Drugs with antihistaminic properties as a cause of atypical cutaneous lymphoid hyperplasia

A diagnostic dilemma: distinguishing a sulfasalazine induced DRESS hypersensitivity syndrome from a CD30 + lymphoma in a young patient

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe hypersensitivity reaction characterized by cutaneous rash, lymphadenopathy, fever, eosinophilia, leukocytosis, and life-threatening organ dysfunctions. We describe the case of a 26 year old patient admitted to the Emergency Department for DRESS syndrome after sulfasalazine treatment for rheumatoid arthritis in the right knee. Whole body computer tomography showed multiple neck, chest, and abdominal lymphadenopathy with splenomegaly, massive ascites and severe hepatic cytolysis. Serology results for Epstein-Barr Virus (EBV), influenza, measles, rubella, hepatitis A and B were negative. The histologic analysis of skin, lymph node and bone marrow biopsies could not indicate a classical Hodgkin's Disease or iatrogenic immunodeficiency/EBV-associated lymphoproliferative disorder (LPD), Hodgkin type. The relatively small caliber of the CD30 + immunoreactive blastoid cells in the lymph nodes suggested reactive immunoblasts rather than Hodgkin cells. The morphologic aspects of the lymph node biopsies with predominance of T-cells were compatible with the diagnosis of a sulfasalazine-induced DRESS syndrome as the patient had a high RegiSCAR score for DRESS. [DRESS Syndrome Foundation: Diagnosis and Treatment. (2023)] The patient's complex clinical course, marked by two hospital admissions, highlights the challenges in diagnosing and managing DRESS. This case underscores the need for individualized care, close patient monitoring, and further research to better understand DRESS's underlying mechanisms and optimal therapeutic strategies.

EBER in situ hybridization in subcutaneous aluminum granulomas/lymphoid hyperplasia: A diagnostic clue to differentiate injection-associated lymphoid hyperplasia from other forms of pseudolymphomas and cutaneous lymphomas

BACKGROUND

Subcutaneous vaccination or desensitization may induce persistent nodules at the injection sites. Without the knowledge of prior injection, histopathological work-up may be challenging.

OBJECTIVE

Aim of this study was to contribute to the histopathological work-up of unclear subcutaneous nodules, especially their differentiation from cutaneous lymphoma.

METHODS

We retrospectively reviewed clinical data and histopathological slides of four patients with subcutaneous nodules, which were suspected to suffer from cutaneous T- or B-cell lymphoma. Sections of these cases and 12 negative controls were stained with hematoxylin and eosin and a standardized immunohistochemical panel of B- and T-cell markers including EBER in situ hybridization as well as electron microscopy.

RESULTS

In all cases, large histiocytes with granular cytoplasm compatible with intracellular aluminum hydroxide were present. EBER in situ hybridization revealed positive staining of these granular histiocytes while staining was absent in negative controls.

LIMITATIONS

Post hoc completion of medical history revealed that vaccination or specific immunotherapy had been applied before at the biopsy site in only three out of four patients; one patient was lost to follow-up.

CONCLUSION

EBER in situ hybridization is an adjunctive tool to differentiate aluminum-induced granuloma/lymphoid hyperplasia from other forms of pseudolymphoma and cutaneous B- or T-cell lymphomas.

Clinical and Histopathological Characteristics of Cutaneous Lymphoid Hyperplasia: A Comparative Study According to Causative Factors

Cutaneous lymphoid hyperplasia (CLH) is a heterogeneous type of reactive lymphocytic infiltration resembling cutaneous lymphoma clinically and histopathologically. Few studies describe the relationship between the causative agents and histopathological and immunohistochemical characteristics of CLH. We investigated the clinical and histopathological characteristics of 50 patients with cutaneous CLH and analyzed them according to causative factors and predominant cell types (B or T cells). We retrospectively reviewed medical records to identify causative agents, and histopathological and immunohistochemical features. The majority of infiltrating lymphocytes were T cells (60%). T cell-dominant CLH showed papuloplaque lesions, whereas B cell-dominant CLH lesions were nodular. The infiltration pattern differed between T and B cells. In terms of prognosis, B-cell-predominant lesions tended to respond better to treatment than T-cell-predominant lesions. Hair dyes tended to be associated with multiple CLH lesions in older patients. CLH lesions associated with drugs were located on the head and neck. Insect bites were likely to cause a solitary papular lesion. Histopathologically, infiltration depth was located more superficially than other causes and featured intense eosinophilic infiltration. Thus, our study demonstrated that CLH presents different clinicopathological features according to causative agents and predominant lymphocytic types.

Lymphoma or pseudolymphoma: A report of six cases and review of the literature

To explore and compare the clinical presentations and pathologic features of cutaneous pseudolymphomas (CPL) with primary cutaneous lymphomas. Review literature in order to improve the treatment of CPL. Six cases of CPLs were collected. The clinical, pathologic, and immunohistochemical features were performed and analyzed in Peking Union Medical College Hospital in 2018. Of six patients, the distributions and clinical manifestations of skin lesions are varied. The pathologic features consisted of atypical prominent lymphocytes infiltration. Of them, two cases imitated mycosis fungoides, one case mimicked primary cutaneous aggressive pidermotropic CD8+ cytotoxic T-cell lymphoma, one case was diagnosed as Jessner-Kanof lymphocyte infiltration and two cases primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder. With respect to etiology, one was result from insects bite and the others were on account of drugs. All cases were treated with systemic or local glucocorticoid. The skin lesions and systemic symptoms showed notable improvement after treatment. Follow-up visits were 2 years, half a year, and months, respectively, without relapse. These unique types of CPL were similar to cutaneous lymphomas in clinical manifestation and pathology. They were all sensitive to the treatment of externally or orally using glucocorticoid. The prognosis is generally good but needs long-term follow-up.

Epidermotropic B-Cell Lymphoma: A Unique Subset of CXCR3-Positive Marginal Zone Lymphoma

BACKGROUND

Epidermotropic B-cell lymphoma is a very rare entity that has primarily been reported in the literature as anecdotal case reports. The majority of the reported cases exhibit a diffuse skin rash affecting middle-aged to older adults with a male predominance. The exact mechanism of marginal zone B-cell localization to the epidermis is unclear.

MATERIAL AND METHODS

To describe a very rare subset of cutaneous B-cell lymphoma and explore potential pathogenetic mechanisms for the epidermotropic tendency, the hospital database and literature review was conducted to isolate cases of epidermotropic B-cell lymphoma. Routine hematoxylin and eosin stain followed by selective phenotypic studies.

RESULTS

Two of the cases were encountered in the hospital database, whereas 5 cases have been previously reported; material was requested on previously reported cases and was received on 3 of them. In one of the 2 cases encountered in our database, the patient presented with a progressive skin rash over 7 months resembling pityriasis rosea. Subsequent to a diagnosis of B-cell lymphoma, further staging revealed bone marrow involvement. The other patient, an elderly female, presented with isolated nodules. The biopsies of both cases showed areas of superficial band-like lymphocytic infiltration with large monocytoid appearance and an epidermotropic pattern of lymphocyte migration into the epidermis. Neoplastic cells were extensively positive for CD20, CD79a, and BCL-2 and negative for CD10 and BCL-6. Of interest, a similar pityriasis rosea-like presentation was encountered in the cases reported in the literature. All patients were elderly males with established bone marrow, peripheral blood, and spleen involvement several months to years after the initial cutaneous presentation in 3 of them. None of the patients to date have died of lymphoma. CXCR3 epidermotropic B cells were detected in both our cases and in 3 of the 3 previously published cases.

CONCLUSIONS

Epidermotropic B-cell lymphoma represents a subset of marginal zone lymphoma characterized by a papulosquamous rash most frequently resembling pityriasis rosea, occurring almost exclusively in older males. We speculate that aberrant expression of CXCR3 in marginal zone lymphoma of the skin is associated with migration of lymphoma cells to the epidermis and could lead to an epidermotropic pattern given the known role of CXCR3 expression in neoplastic T cells in the localization of mycosis fungoides to the epidermis. There is a tendency toward bone marrow, spleen, and peripheral blood involvement.

Investigating potential exogenous tumor initiating and promoting factors for Cutaneous T-Cell Lymphomas (CTCL), a rare skin malignancy

Most skin malignancies are caused by external and often preventable environmental agents. Multiple reports demonstrated that cutaneous T-cell lymphomas (CTCL) can occur in married couples and cluster in families. Furthermore, recent studies document geographic clustering of this malignancy in Texas as well as in other areas of the United States. Multiple infectious, occupational, and medication causes have been proposed as triggers or promoters of this malignancy including hydrochlorothiazide diuretics, Staphylococcus aureus, dermatophytes, Mycobacterium leprae, Chlamydia pneumoniae, human T-Cell lymphotropic virus type 1 (HTLV1), Epstein-Barr virus (EBV), and herpes simplex virus (HSV). In this report, we review recent evidence evaluating the involvement of these agents in cancer initiation/progression. Most importantly, recent molecular experimental evidence documented for the first time that S. aureus can activate oncogenic STAT3 signaling in malignant T cells. Specifically, S. aureus Enterotoxin type A (SEA) was recently shown to trigger non-malignant infiltrating T cells to release IL-2 and other cytokines. These signals upon binging to their cognate receptors on malignant T cells are then able to activate STAT3 and STAT5 oncogenic signaling and promote cancer progression and IL-17 secretion. In light of these findings, it might be important for patients with exacerbation of their CTCL symptoms to maintain high index of suspicion and treat these individuals for S. aureus colonization and/or sepsis with topical and systemic antibiotics.

Lamotrigine-induced Hypersensitivity Syndrome with Histologic Features of CD30+ Lymphoma

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome or drug-induced hypersensitivity syndrome (DIHS) is a severe adverse drug reaction. It can present with clinical, paraclinical, and histological findings mimicking skin and/or systemic lymphomas. We report the first case of a lamotrigine-induced DRESS with histologic features of a cutaneous CD30+ lymphoma. The patient responded well to a tapering course of oral steroids. This case highlights the atypical presentation of a lamotrigine-induced DRESS/DIHS in the presence of a cutaneous and a lymph node CD30 + lymphocytic infiltrate mimicking systemic lymphoma. Pathologists and clinicians must be aware of this “lymphomatous” presentation of drug reactions.

Hydrochlorothiazide and cutaneous T cell lymphoma: prospective analysis and case series

BACKGROUND

Mycosis fungoides (MF) and leukemic Sézary syndrome (SS) are the most common cutaneous T cell lymphomas (CTCL), but their etiology remains unknown. After patients were observed with hydrochlorothiazide (HCTZ)-associated CTCL, HCTZ was examined as a putative chronic antigen in a cohort of prospectively staged patients.

METHODS

Demographic and drug exposure data was examined from 1443 confirmed MF and SS patients. Hypertensive CTCL patients were divided into HCTZ users or nonusers for statistical analysis by chi-square and t tests. Causality in a case series was rated by the Naranjo Adverse Drug Reaction Probability Scale.

RESULTS

A total of 815 of 1443 MF and SS patients (56.5%) were hypertensive; 205 (25.2%) were taking HCTZ at initial staging. Comparing stage of patients who were using or not using HCTZ, the most significant difference was between stage I and stage IV (odds ratio of 0.45; 95% confidence interval of 0.25-0.78, P = .003), demonstrating reduced likelihood of being stage IV in patients who were on HCTZ. Seventy-seven percent of the MF patients on HCTZ were stage I. A total of 125 patients of 196 (63.8%) started HCTZ prior to developing CTCL lesions, and 35 of 121 (28.0%) started within 1 year of first skin rash. Thirty-six of 125 patients (28.8%) experienced complete or partial remissions after discontinuing HCTZ. A monoclonal T cell receptor rearrangement was detected more frequently in the hypertensive stage I patients not taking HCTZ as compared with those who were (55.3% vs 69.1%, P = .032). Three patients were rechallenged and developed MF lesions that resolved or improved with discontinuation.

CONCLUSIONS

HCTZ is commonly prescribed and may be a putative antigen in a small subset of early MF patients. Careful drug histories and a trial off medication are warranted.

Histopathology of drug eruptions - general criteria, common patterns, and differential diagnosis

Drug eruptions are among the most common inflammatory diseases of the skin and also among those biopsied most often. Yet, the value of histopathologic examination of drug eruptions has often been disputed. One reason is that the spectrum of histopathologic changes in drug eruptions is broad. Nevertheless, each histopathologic pattern assumed by drug eruptions has a limited number of differential diagnoses, and numerous criteria and clues are available to distinguish drug eruptions from other diseases associated with those patterns. By recognition of common patterns, consideration of differential diagnoses, and attention to distinct clues, a histopathologic diagnosis of drug eruption can usually be made with confidence.

The pathogenesis of primary cicatricial alopecias

Cicatricial (scarring) alopecia results from irreversible damage to epithelial stem cells located in the bulge region of the hair follicle, generally as a result of inflammatory mechanisms (eg, in the context of autoimmune disease). In primary cicactricial alopecia (PCA), the hair follicle itself is the key target of autoaggressive immunity. This group of permanent hair loss disorders can be classified into distinct subgroups, characterized by the predominant peri-follicular inflammatory cell type. In none of these PCA forms do we know exactly why hair follicles begin to attract such an infiltrate. Thus, it is not surprising that halting or even reversing this inflammation in PCA is often extremely difficult. However, increasing evidence suggests that healthy hair follicle epithelial stem cells enjoy relative protection from inflammatory assault by being located in an immunologically "privileged" niche. Because this protection may collapse in PCA, one key challenge in PCA research is to identify the specific signaling pathways that endanger, or restore, the relative immunoprotection of these stem cells. After a summary of pathobiological principles that underlie the development and clinical phenotype of PCA, we close by defining key open questions that need to be answered if more effective treatment modalities for this therapeutically very frustrating, but biologically fascinating, group of diseases are to be developed.

Investigation on the association between atopic dermatitis and the development of mycosis fungoides in dogs: a retrospective case-control study

In human medicine, the relationship between the immunodysregulation observed in atopic dermatitis (AD) and the development of mycosis fungoides (MF) has triggered considerable interest due to the increasing number of patients with MF who have a previous history of AD. The purpose of this retrospective case-control study was to investigate whether dogs diagnosed with MF were more likely to have AD. The records of 96 000 canine patients at the University of Florida were searched. Inclusion criteria were a clinical and histological diagnosis of MF. Dogs admitted to the University of Florida, Veterinary Medical Center during the same time period (1991-2004) without a diagnosis of MF were included as controls. Four controls for each study dog were randomly selected (matched by year of admission). Frequency of AD and other exposure variables were compared among case and control dogs by using conditional logistic regression. Records of 19 dogs with a diagnosis of MF were identified. Five of them (5/19, 26.3%) had previous diagnosis of AD. The odds of having MF was 12 times (OR = 12.54; 95% CI = 1.95-80.39; P < 0.01) higher in dogs with AD than in dogs without AD. In conclusion, this study suggests an association between AD and MF in dogs. Future studies are necessary to confirm this finding and to investigate the pathogenic mechanisms involved in this association.

Cutaneous marginal zone B-cell lymphoma in the setting of fluoxetine therapy: a hypothesis regarding pathogenesis based on in vitro suppression of T-cell-proliferative response

INTRODUCTION

Drugs may be an important cause of atypical lymphocytic infiltration. Oftentimes, these infiltrates are in the context of pseudolymphomata. We report a patient who developed lymphocytoma cutis temporally associated with initiation of fluoxetine therapy that later went on to develop cutaneous marginal zone B-cell lymphoma. The response of peripheral blood lymphocytes to fluoxetine and other drugs was examined in an attempt to ascertain the potential role for drugs in the propagation of these infiltrates.

MATERIALS AND METHODS

Routine light microscopic analysis and phenotypic studies were performed on tissue obtained from a skin biopsy. Lymphocyte mitogenic studies were carried out using increasing concentrations of fluoxetine, bupropion, and two anticonvulsants.

RESULTS

An initial biopsy was consistent with lymphocytoma cutis. The patient stopped fluoxetine associated with lesional regression. The lesions recurred despite being off fluoxetine; a repeat biopsy was compatible with marginal zone lymphoma. Lymphocyte proliferation assays revealed a suppressive effect on T-lymphocyte proliferation at physiologic concentrations. Other tested drugs did not have a similar suppressive effect.

CONCLUSIONS

Fluoxetine may be associated with pseudolymphomata and marginal zone lymphoma. The inhibitory effects on T-lymphocyte function and more specifically T-suppressor function may lead to excessive antigen-driven B-cell proliferation.

My approach to superficial inflammatory dermatoses

Superficial inflammatory dermatoses are very common and comprise a wide, complex variety of clinical conditions. Accurate histological diagnosis, although it can sometimes be difficult to establish, is essential for clinical management. Knowledge of the microanatomy of the skin is important to recognise the variable histological patterns of inflammatory skin diseases. This article reviews the non-vesiculobullous/pustular inflammatory superficial dermatoses based on the compartmental microanatomy of the skin.

Vaccination-induced cutaneous pseudolymphoma

BACKGROUND

Although mild early cutaneous transient reactions to vaccinations are common, late-onset chronic lesions have been scarcely reported. We report herein a series of 9 patients presenting with cutaneous and subcutaneous pseudolymphoma.

OBSERVATIONS

Nine patients presenting with late-onset, chronic skin lesions occurring at the site of antihepatitis B (8 cases) and antihepatitis A (one case) vaccination were reported. Histopathologic and immunohistochemic studies, and molecular analysis of clonality of skin biopsy specimens, were performed. Furthermore, the presence of vaccine products was investigated in skin lesions by using histochemical, microanalytic, and electronic microscopy techniques.

RESULTS

Histopathologic studies showed dermal and hypodermal lymphocytic follicular infiltrates with germinal center formation. The center of follicles was mostly composed of B cells without atypia, whereas CD4+ T cells were predominant at the periphery. Molecular analysis of clonality revealed a polyclonal pattern of B-cell and T-cell subsets. Aluminium deposits were evidenced in all cases by using histochemical staining in all cases, and by microanalysis and ultrastructural studies in one case. Associated manifestations were vitiligo (one case) and chronic fatigue with myalgia (two cases).

CONCLUSION

Cutaneous lymphoid hyperplasia is a potential adverse effect of vaccinations including aluminium hydroxide as an adjuvant. Further prospective studies are warranted to evaluate the incidence of this complication in the immunized population.

Assessment of T-cell Clonality via T-cell Receptor-γ Rearrangements in Cutaneous T-cell–Dominant Infiltrates Using Polymerase Chain Reaction and Single-stranded DNA Conformational Polymorphism Assay

Discerning the pathologic significance of cutaneous T-cell infiltrates can pose a diagnostic challenge for dermatopathologists. Reactive conditions such as drug-associated lymphomatoid hypersensitivity and lymphomatoid lupus erythematosus can demonstrate lymphoid atypia and a phenotype resembling cutaneous T-cell lymphoma (CTCL). Further, lymphoid dyscrasias such as pityriasis lichenoides chronica, large plaque parapsoriasis, and atypical pigmentary purpura confuse the picture because they not only mimic CTCL but also represent prelymphomatous states with inherent malignant potential. Although the emergence of a dominant clone has been considered a clue indicative of a T-cell dyscrasia, there are reports concerning the identification of monoclonality in biopsies of reactive lymphoid infiltrates. We have conducted a modified single-stranded DNA conformational polymorphism (SSCP) assay using paraffin-embedded, formalin-fixed tissue on 92 T-cell-rich biopsies to determine the relative specificity and sensitivity of this methodology. In addition, laser capture microdissection (LCM) was performed on 22 of the 92 samples to isolate the area of interest and to compare its specificity and sensitivity with those SSCP assays performed without LCM. We found that monoclonality or oligoclonality is 86% specific for preneoplastic and neoplastic states, whereas the finding of polyclonality appears to be relatively specific for a reactive process. Some cases of reversible T-cell dyscrasia produced a molecular profile mimicking lymphoma or prelymphomatous states by virtue of monoclonality or oligoclonality. Although LCM appears to improve the sensitivity for detecting preneoplastic conditions, the relative specificity appears to be the same as that encountered with routine SSCP.

Carbamazepine-Induced Pseudo Mycosis Fungoides

OBJECTIVE

To report a case of pseudo mycosis fungoides due to carbamazepine.

CASE SUMMARY

A 54-year-old man experienced a skin lesion resembling mycosis fungoides without any systemic symptoms or signs 2 months after he had begun carbamazepine treatment for his seizures. Skin-punch biopsy specimens revealed mycosis fungoides-like histopathologic appearance. After drug discontinuation, the patient experienced complete remission of the clinical and pathologic findings. This suggests a diagnosis of pseudo mycosis fungoides due to carbamazepine.

DISCUSSION

Mycosis fungoides is the cutaneous T-cell lymphoma of the skin that needs aggressive chemotherapy and radiation treatment. Pseudo mycosis fungoides is a condition caused by certain drugs that has a similar clinical and histopathologic appearance to mycosis fungoides. When the causative drug is discontinued, the lesions resolve completely.

CONCLUSIONS

An objective causality assessment revealed that carbamazepine was highly probable as the cause of the adverse reaction. Patients who are diagnosed with mycosis fungoides should be asked about any drug use, and clinicians should recognize signs of pseudo mycosis fungoides.

The utility of the in situ detection of T-cell receptor Beta rearrangements in cutaneous T-cell-dominant infiltrates

The diagnostic assessment of cutaneous T-cell infiltrates is problematic for dermatopathologists. A variety of conditions, including lymphomatoid hypersensitivity reactions and lymphomatoid lupus erythematosus, can demonstrate lymphoid atypia and phenotypic changes that can mimic cutaneous T-cell lymphoma (CTCL). A similar issue revolves around lymphoid dyscrasias, which includes parapsoriasis, atypical pigmentary purpura, pityriasis lichenoides chronica, indeterminate lymphocytic lobular panniculitis, and lymphomatoid papulosis, which can progress to CTCL. A reverse transcription (RT) in situ PCR assay for T-cell receptor beta rearrangements (TCRbeta) was used to assess T-cell clonality in formalin-fixed, paraffin-embedded tissues. In 7 of 8 cases of classic CTCL, the RT in situ PCR assay for TCRbeta rearrangement showed monoclonality; the other was biclonal. Further, in cases with multiple lesions over time, the same T-cell clone could be detected including in those patients whose biopsies showed large-cell transformation. Monoclonality was also demonstrated in each of 2 cases of cutaneous lymphomatoid papulosis. Demonstration of oligoclonality (and one case of biclonality) by RT in situ PCR was confined to those cases that either represented prelymphomatous conditions such as large plaque parapsoriasis or pityriasis lichenoides or lesions of drug-induced lymphomatoid hypersensitivity that all demonstrated clinical regression. In conclusion, RT in situ PCR for TCRbeta, which can be done on formalin-fixed biopsies and allows direct correlation of the molecular data with the histology, is a useful adjunctive test in the differentiation of CTCL from its mimics.

Lymphomatoid drug eruption mimicking digitate dermatosis: cross reactivity between two drugs that suppress angiotensin II function

A 75-year-old male presented with an eruption characteristic of digitate dermatosis. The eruption cleared completely after discontinuation of lisinopril (angiotensin converting enzyme inhibitor). Eighteen months later a similar eruption recurred after using valsartan (a competitive inhibitor of angiotensin II receptor). The eruption cleared after discontinuation of valsartan. Histologic findings in both eruptions were consistent with lymphomatoid drug eruption. This case is interesting in that the eruption occurred after the intake of two structurally unrelated drugs that interfere with angiotensin II function. This observation may shed light on the mechanisms that may be operative in provoking the lymphomatoid drug eruption.

Cutaneous lymphoid hyperplasia: a lymphoproliferative continuum with lymphomatous potential

Cutaneous lymphoid hyperplasia (CLH) has been proposed to be the benign end of a continuum of lymphoproliferative disorders with cutaneous lymphoma at its malignant extreme. An intermediate condition, known as "clonal CLH," was first recognized by us and shown to be a transitional state capable of eventuating in overt lymphoma. To better determine the prevalence of dominant clonality and risk of lymphoma among CLH cases, we studied the immunohistology and clonality of fresh-frozen samples from 44 CLH patients referred to a multidisciplinary cutaneous lymphoproliferative disorders program. Using a large panel of lymphoid markers, the cases were divided into 38 typical mixed B-cell/T-cell type CLH and 6 T-cell-rich type (T-CLH), the latter containing > 90% T cells. Of the 44 patients, 38 had solitary or localized lesions (4 cases of T-CLH), and 6 had regional/generalized lesions (2 cases of T-CLH). Forty cases were of idiopathic etiology. Suspected etiologies among 4 other cases included mercuric tattoo pigment, doxepin, clozapine, and bacterial infection. Immunoglobulin heavy chain (IgH) and T-cell receptor (TCR)-gamma gene rearrangements (GR) were studied using polymerase chain reaction assays, which are approximately 80% sensitive. Overall, 27 cases (61%) showed clonal CLH: 12 IgH+ (27%; 3 cases of T-CLH); 13 TCR+ (30%; 1 case of T-CLH); and 2 IgH+/TCR+ (4%; neither case was T-CLH). Two cases (4%; 1 case of T-CLH) progressed to cutaneous B-cell lymphoma. Both of these patients presented with regional lesions. Our findings indicate that clonal overgrowth is common in CLH, links CLH to lymphoma, and probably involves both B- and T-cell lineages (although TCR GR by B cells and vice versa could not be ruled out). The high prevalence of dominant clonality in our series may have resulted from the sensitivity of our PCR assays as well as patient selection.

Atypical lymphoid infiltration occurring at the site of a healed varicella zoster infection

Herpes zoster infection has been associated with a number of cutaneous reactions. The authors report the first case of a patient with an atypical epidermotropic lymphoid infiltrate that arose within skin previously affected by herpes varicella zoster. The differential diagnosis of such lesions and review of literature on previous cutaneous infiltrates occurring at sites of zoster infection are discussed

Pagetoid reticulosis: a case report and review of the literature

The histologic finding of a pagetoid epidermotropic growth pattern is associated with a variety of conditions that range from reactive to neoplastic in nature. Included among these conditions is the uncommon skin disorder pagetoid reticulosis. Pagetoid reticulosis may present clinically as a solitary, indolent plaque-like lesion. Conversely, it may manifest as a more generalized clinically aggressive disease. The generalized form may develop into systemic lymphoma, leading to severe morbidity and death. We present a case of pagetoid reticulosis of the perioral region, a rare anatomic site for this condition. Histopathologic and immunohistochemical findings were consistent with a diagnosis of isolated pagetoid reticulosis. This review discusses the nature of pagetoid reticulosis and addresses past and current concepts regarding the condition.

Drug-induced reversible lymphoid dyscrasia: a clonal lymphomatoid dermatitis of memory and activated T cells

Certain systemic conditions predispose patients to excessive lymphocyte responses to immune-perturbing drugs, which may progress to malignant lymphoma. Many pathologists and clinicians believe that differentiation of pseudolymphoma from cutaneous T cell lymphoma (CTCL) can be reliably made through phenotypic and molecular analysis. We encountered 15 cases of atypical cutaneous T-cell lymphoid hyperplasia in the setting of drug therapy. We explored phenotypic anomalies using antibodies to CD2, 3, 4, 7, 8, 20, 30 and CD62 K and sought T-cell receptor gene rearrangements by a polymerase chain reaction methodology. The lymphoid infiltrates showed reproducible CD7 and/or CD62 K deletion in concert with T cell clonality and variable CD30 positivity-findings similar to those of CTCL-but the rashes resolved or improved substantially after drug modulation. We hypothesize that the infiltrates represent an unrepressed expansion of CD7- and CD62 K-negative activated memory T lymphocytes in response to antigenic triggers. We propose the term "drug-induced reversible lymphoid dyscrasia" to describe this entity.

Cutaneous T-cell lymphoproliferative disorders: approach for the surgical pathologist: recent advances and clarification of confused issues

Cutaneous T-cell lymphoproliferative disorders (CTCLs) remain a subject of confusion and controversy. In this review, the authors discuss diagnostic criteria and classification, including the role of immunohistochemistry and gene rearrangement studies. In addition, cutaneous T-cell pseudolymphomas, the current status of parapsoriasis and other premalignant syndromes, and the clinicopathological variants of mycosis fungoides are discussed. CD30-positive lymphoproliferative disorders and a number of rare variants of CTCL including granulamatous slack skin, subcutaneous (panniculitic) T-cell lymphoma, gamma-delta cutaneous lymphoma, NK/NK-like T-cell lymphoma, and primary cutaneous CD8-positive epidermotropic cytotoxic T-cell lymphoma are also considered.

Necrotizing eosinophilic folliculitis as a manifestation of the atopic diathesis

BACKGROUND

Eosinophilic folliculitis (EF) is an idiopathic eruption of sterile pustules and papules involving the trunk, face, and extremities, associated in many cases with human immunodeficiency virus (HIV) infection. The classic histopathology is one of follicular-based, eosinophilic spongiosis with variable microabscess formation. We describe nine HIV-negative patients who manifested a novel form of pustular EF in the setting of atopy.

MATERIALS AND METHODS

Paraffin sections of skin biopsies from ten patients, stained with hematoxylin and eosin and special preparations to evaluate for microbial pathogens, were examined. Detailed clinical histories and serologic studies were obtained.

RESULTS

Among the clinical presentations in seven men, two women, and one girl (age range, 11-62 years) were ulcerative and/or nodular plaques mainly on the face and/or extremities, sometimes in an annular configuration. The clinical considerations included deep mycotic infection, ulcerative herpes, systemic vasculitis, Mucha Haberman disease, and pyoderma gangrenosum. All patients had a personal and/or family history of atopy. Co-existent medical illnesses included psoriasis, lupus erythematosus, and lymphoproliferative disease. One patient was on a calcium channel blocker, one on multiple antidepressants, and two on antihistamines, all of which are associated with immune dysregulation. All skin biopsies showed variable intra- follicular eosinophilic microabscesses, follicular necrosis, folliculocentric necrotizing eosinophilic vasculitis, marked degeneration of connective tissue fiber elements, and striking tissue eosinophilia, including flame figure formation and dermal eosinophilic abscesses. Apart from commensals, such as Pityrosporum and Demodex, microbial pathogens were not identified.

CONCLUSIONS

The presentations differed from conventional EF by virtue of a strong association with atopy and by the presence of ulceration, nodule formation, follicular and dermal necrosis, and eosinophilic vasculitis. We propose the term "necrotizing eosinophilic folliculitis," and suggest that the basis of this novel form of EF is an unrepressed T-helper lymphocyte type 2 (Th2)-dominant response to various epicutaneous stimuli in patients with atopy, the prototypic immune dysregulatory state associated with a Th2-dominant cytokine milieu.

Cutaneous pseudolymphoma, lymphomatoid contact dermatitis type, as an unusual cause of symmetrical upper eyelid nodules

We describe a 74-year-old woman who rapidly developed bilateral voluminous nodules on the upper eyelids, following 4 months' treatment for chalazion. Histological and immunohistochemical findings were suggestive of cutaneous pseudolymphoma (CPL), and extensive screening for malignant lymphoma (ML) remained negative. Cutaneous pseudolymphomas are inflammatory diseases that can simulate ML either clinically, histopathologically, or both. They are a rare cause of nodules of the upper eyelids, usually characterized by a benign evolution, that can be secondary to ultraviolet sensitivity, adverse reactions to systemic medications and contact sensitization, among others. In our case, epicutaneous patch tests were strongly positive for a series of allergens contained in the ophthalmological preparations used; therefore, they were suggestive that the patient had CPL, lymphomatoid contact dermatitis type. In addition, the patient had been treated previously with several drugs, known to cause CPL and immune dysregulation. Complete regression of the lesions required treatment with systemic steroids and chlorambucil. No relapse occurred within a 5-year follow-up period.

Cutaneous lymphoid hyperplasias

Benign hyperplastic lymphoid infiltrates of the skin (pseudolymphoma, older term) simulate lymphoma clinically and histologically. They can be divided into B-cell predominant (typical cutaneous lymphoid hyperplasia (CLH), angiolymphoid hyperplasia, Kimura's disease, and Castleman's disease) and T-cell predominant (T-cell CLH, lymphomatoid contact dermatitis, and lymphomatoid drug eruption). Both types may represent exaggerated reactions to diverse external antigens (insect bite, tattoo, zoster, trauma, among others). A composite assessment of clinical presentation and behavior, routine histology, immunophenotyping, and molecular studies is essential for the diagnosis of benign cutaneous lymphoid infiltrates. Treatment includes antibiotics, intralesional and systemic corticosteroids, excision, radiotherapy, and immunosuppressants. Treatment depends on the assessment and biologic behavior, which is usually benign. Molecular biologic analysis has shown that a significant proportion of cases harbor occult B- or T-cell clones (clonal CLH). Progression to overt cutaneous lymphoma has been observed in a minority of cases. Patients with clonal populations of B or T cells and persistent lesions should be closely observed for emergence of a lymphoma.

Solitary skin lesions with histopathologic features of early mycosis fungoides

Mycosis fungoides (MF) is a cutaneous T-cell lymphoma that usually begins with cutaneous patches that evolve into plaques and tumors. A few recent reports describe a solitary variant of MF distinct from localized pagetoid reticulosis, a disease in which solitary verrucous lesions occur on acral skin. Solitary skin lesions with some of the histopathologic features of MF rarely occur during treatment with several drugs, especially antidepressants or antihistamines. We analyzed the clinicopathologic features of 20 patients with solitary skin lesions showing histopathologic features of patch- or early plaque-stage MF. Eight men and 12 women (mean age 50.6, range 23-82, median 49) had solitary, small erythematous patches or plaques located on the trunk (16 cases, 6 of them on the breast), upper extremities (3 cases), and inguinal region (1 case). Ten patients were treated with one or more drugs; only two of them received antidepressants or antihistamines. Histopathologic examination revealed in all cases a band-like infiltrate in the upper dermis, frequently with epidermotropism of solitary lymphocytes. Atypical lymphocytes were present in a minority of cases. Immunohistology showed a predominance of CD3+ T lymphocytes, in most cases admixed with clusters of CD20+ B-cells. Only a small proportion of the infiltrate was CD8+. Molecular analysis of the rearrangement of the T-cell receptor genes was performed in 16 cases using the polymerase chain reaction (PCR) technique and revealed a monoclonal band in 8 of them. After surgical excision, 2/14 patients had a recurrence near the surgical scar. In 18 patients with complete follow-up data, no evidence of "classic" MF could be observed after a mean follow-up of 31.9 months. Solitary skin lesions with the histopathologic features of MF can be considered as a distinct clinicopathologic entity, probably representing a solitary variant of mycosis fungoides.

Atypical pigmentary purpura: a clinical, histopathologic, and genotypic study

BACKGROUND

The pigmentary purpuras (PPs) are a heterogeneous group of dermatoses defined by specific clinicopathologic features but sharing, at the light microscopic level, superficially disposed dermal lymphocytic infiltrates and hemorrhage. The term atypical pigmentary purpura (APP) is used by the authors in reference to cases of PP in which individual lesions, although clinically presenting as PP, show morphological features typically associated with mycosis fungoides (MF) including Sezary cells and epidermotropism. The integrated concept of lymphocyte atypia and PP is a confusing and enigmatic one to which reference in the literature has been previously made. Specifically, there are reports of PP presaging fully evolved MF, lymphoid atypia has been identified in lesions of routine PP and MF with purpuric features has been described. The clinical, light microscopic, and genomic features of biopsied lesions showing pathological features of APP and which clinically were consistent with PP is explored.

DESIGN

The light microscopy of skin biopsy specimens from 34 patients with a pathological diagnosis of APP was correlated to medical and drug histories. In 14 cases, adequate tissue was present in the paraffin blocks to allow DNA extraction. The polymerase chain reaction (PCR) was used in these 14 cases to explore for rearrangement of the T-cell receptor. Fisher's exact test and pair wise exact tests were used to assess the significance of histological differences between cases determined by dinical features to be of MF- or drug-related origin, or to be idiopathic in nature.

RESULTS

Of 34 patients, 7 were held to have MF related PP; specifically these patients had violaceous, infiltrative, variably purpuric plaques on trunk, buttocks, and thighs accompanied by typical PP lesions which occurred either concomitant to or preceded the MF lesions. In 10 cases, a diagnosis of idiopathic PP was made whereby the clinical presentation was characteristic of PP; there were no concomitant lesions suspicious for MF and a drug-based origin was excluded. A drug-based origin was established in 17 patients based on lesional onset related to initiation (5 patients) and/or resolution after discontinuation (12 patients) of drugs including calcium channel blockers, lipid-lowering agents, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, antihistamines, antidepressants, or analgesics. There was considerable overlap histologically between all 3 groups including the degree of lymphoid atypia in the dermis, the presence of dermal-based Sezary cells, the degree and pattern of epidermotropism, the paucity of other inflammatory cell elements, and the presence of laminated dermal sclerosis. Morphological features predictive of MF related APP over the other 2 groups were intraepidermal lymphocytes which were more atypical than the dermal-based infiltrate. Intraepidermal Sezary cells were less frequent in biopsies of drug-related APP relative to idiopathic PP (IPP) and MF related PP. PCR studies conducted in 14 cases (2 cases of MF, 6 cases of drug-related APP, and 6 cases of IPP) revealed clonality in 2 cases of drug-related APP and 2 cases of IPP; the 2 studied MF-related cases did nor show clonal restriction.

CONCLUSION

APP should not be equated with purpuric MF; it is not necessarily a precursor lesion of MF, and may be of drug-based origin. Clinical features are critical to the final assessment because there is overlap pathologically in the 3 clinical subtypes of APP.

Recent advances in the pathology of cutaneous drug eruptions

Cutaneous reactions to drug therapy may be of either immunologic or nonimmunologic etiology. It is important that the dermatologist and pathologist be familiar with these types of cutaneous reactions. This article discusses the clinical features, pathogenesis, and histopathology of various cutaneous drug eruptions.

Lichenoid and subacute cutaneous lupus erythematosus-like dermatitis associated with antihistamine therapy

The authors report the occurrence of lichenoid and/or subacute lupus erythematosus-like eruptions in a group of patients receiving agents with antihistaminic properties. In 1 of the patients the eruption clinically resembled lichen planus, while in 5 patients the eruption resembled subacute cutaneous lupus erythematosus (SCLE). At a light microscopic level all cases showed a lichenoid dermatitis and in 4 cases the lesions were interpreted as representing subacute lupus-like eruptions by virtue of the presence of alternating cell poor and lichenoid interface dermatitis, suprabasilar lymphocytosis around degenerating keratinocytes, and dermal mucinosis. Despite the resemblance at a clinical and light microscopic level to SCLE, anti-Ro seropositivity could not be established in any of the cases. One case, however, did demonstrate antihistone antibodies in concert with a high antinuclear antibody titer. A causal association was implicated by virtue of lesional resolution following drug withdrawal. The association of cutaneous eruptions resembling SCLE with antihistamine intake is seemingly a novel one. The possible pathogenetic basis of the eruptions is discussed.

Analysis of clonality of atypical cutaneous lymphoid infiltrates associated with drug therapy by PCR/DGGE

Atypical lymphocytic infiltrates that mimic cutaneous lymphoma (ie, pseudolymphoma) are often observed in skin biopsy specimens from patients with altered immune function. The latter may reflect systemic immune dysregulatory states such as collagen vascular disease or human immunodeficiency virus infection. Among the iatrogenic causes are drug therapy with agents that abrogate lymphocyte function. These drugs encompass the anticonvulsants, antidepressants, phenothiazines, calcium channel blockers, and angiotensin-converting enzyme inhibitors. The appellation of lymphomatoid hypersensitivity reaction has been applied to cases of drug-associated pseudolymphoma. Pathologically and clinically, the distinction of such cases from cutaneous lymphoma is difficult. We employed the polymerase chain reaction (PCR) on archival material of proven drug-associated lymphomatoid hypersensitivity reactions both to explore its utility as an adjunct in diagnosis and to investigate the genotypic aberrations induced by drug therapy. Formalin-fixed, paraffin-embedded biopsy specimens from seven cutaneous T-cell lymphomas (CTCL), one nodal T-cell lymphoma, two cutaneous B-cell lymphomas, three typical hypersensitivity reactions, one tonsil, and 14 lymphomatoid hypersensitivity reactions were studied. Control cases for which DNA derived from fresh tissue was used include the Jurkat T-cell tumor line, placenta, one nodal B-cell lymphoma, and one case of reactive lymph node hyperplasia. DNA was obtained and purified by standard methods, then amplified with oligonucleotide primers specific for the T-cell receptor gamma locus and the immunoglobulin heavy chain genes. T-cell amplicons were analyzed by denaturing gradient gel electrophoresis (DGGE) and B-cell amplicons by either nondenaturing polyacrylamide or agarose gel electrophoresis. The nodal and Jurkat T-cell lymphomas, six of seven CTCL, one cutaneous B-cell lymphoma, and 2 of 14 lymphomatoid hypersensitivity reactions showed dominant ("monoclonal") T-cell gene rearrangement patterns, and the remainder of cases were polyclonal. A causal relationship between drug therapy and skin eruption was ascertained in the two patients showing T-cell rearrangements, and both experienced complete and sustained lesional resolution on discontinuation of the implicated drug. The only immunoglobulin heavy chain gene rearrangements detected by PCR were in two of the three B-cell lymphomas. We conclude that PCR/DGGE is a powerful method for assaying T-cell clonality in archival tissue and can aid in the discrimination of reactive from malignant cutaneous infiltrates with appropriate clinicopathologic correlation. Recognition that a monoclonal TCRgamma rearrangement can be observed in cases of drug-associated lymphomatoid hypersensitivity may help in avoiding a misdiagnosis of malignant lymphoma.

Antinuclear antibody seropositivity in patients with cutaneous T-cell lymphoma

BACKGROUND

We attempted to determine the frequency and clinical relevance of antinuclear antibody (ANA) testing and positive ANA test results in patients with cutaneous T-cell lymphoma (CTCL).

METHODS

A retrospective chart and computer record review was conducted to determine the frequency of ANA testing in CTCL patients and the rate of seropositivity. Patients with a positive ANA were further examined to define possible explanations of the positive test.

RESULTS

Of 381 patients with CTCL, 66 (17%) had ANA tests; 8 of these (12.1%) were found to have an ANA titer greater than or equal to 1:40. Of patients with a positive ANA test, one was found to have chronic cutaneous lupus erythematosus histologically and clinically mimicking CTCL. Others were found to have a comorbid connective tissue disorder, some had apparent drug-induced antinuclear antibodies, and some had no identifiable reason for a positive ANA test.

CONCLUSION

ANA seropositivity does not appear to be increased in CTCL patients, and the ANA test remains a useful screening tool for differentiating between CTCL and connective tissue disorders.

Cutaneous pseudolymphomas

Cutaneous pseudolymphoma refers to a heterogeneous group of benign reactive T- or B-cell lymphoproliferative processes of diverse causes that simulate cutaneous lymphomas clinically and/or histologically. The inflammatory infiltrate is bandlike, nodular, or diffuse and is composed predominantly of lymphocytes with or without other inflammatory cells. Depending on the predominant cell type in the infiltrate, cutaneous pseudolymphomas are divided into T- and B-cell pseudolymphomas. Cutaneous T-cell pseudolymphomas include idiopathic cutaneous T-cell pseudolymphoma, lymphomatoid drug reactions, lymphomatoid contact dermatitis, persistent nodular arthropod-bite reactions, nodular scabies, actinic reticuloid, and lymphomatoid papulosis. Cutaneous B-cell pseudolymphomas include idiopathic lymphocytoma cutis, borrelial lymphocytoma cutis, tattoo-induced lymphocytoma cutis, post-zoster scar lymphocytoma cutis, and some persistent nodular arthropod-bite reactions. This review attempts to discuss current aspects of the classification, pathogenesis, clinical spectrum, histopathologic and immunohistochemical diagnosis, and laboratory investigations for clonality in the various types of cutaneous pseudolymphomas.

Atypical lymphoid infiltrates arising in cutaneous lesions of connective tissue disease

Atypical lymphoid infiltrates occurring in the setting of connective-tissue disease (CTD) comprise malignant neoplasms of B-cell or T-cell phenotypes and various reactive lymphoid hyperplasias, such as myoepithelial sialadenitis, lymphocytic thyroiditis, and lymphocytic interstitial pneumonitis. We describe 17 patients with atypical lymphoid infiltrates arising in cutaneous lesions of CTD, the spectrum of which included lupus erythematosus, dermatomyositis, relapsing polychondritis, and lichen sclerosus et atrophicus. There were two principal categories, pseudolymphoma and malignant lymphoma, the former representing 15 of the 17 cases. The clinical and histologic features and possible pathogenetic mechanisms are discussed.

The clinical and histomorphological features of pityriasis rubra pilaris. A comparative analysis with psoriasis

Pityriasis rubra pilaris (PRP) is an idiopathic erythematous scaling eruption which can be difficult to distinguish from psoriasis. We explored the clinical features, including background medical illnesses and potential triggers in patients with PRP, and also its histomorphologic spectrum. Patients with PRP were selected by natural language search of dermatopathology databases containing 250,000 cases accessioned over a 3-year period. A detailed medical history was obtained on each patient via office chart review and patient interviews. We compared the histologic findings in skin biopsies from patients with PRP to those of biopsies matched for site and age from control patients with psoriasis. Certain aspects of the clinical presentations encountered in the study group patients have not been previously emphasized, including eruptions compatible with a vesiculobullous disorder in 4 patients. Several patients had evidence of underlying iatrogenic or systemic immune dysregulatory states and certain triggers could be isolated such as emotional stress and prior exposure to microbial pathogens. Histomorphologic features predictive of PRP included follicular plugging, an increased granular cell layer, and acantholysis. While seen in a minority of biopsies of PRP, morphologic discriminators supportive of a diagnosis of psoriasis included neutrophils in the parakeratotic scale crust, and dermal papillae capillary ectasia with vessels lying in direct apposition to the epidermis. Other morphologic features were encountered in biopsies of PRP which have received little emphasis in the dermatopathology literature, including epithelial atrophy, significant dermal inflammation, the presence of eosinophils and plasma cells within the inflammatory infiltrates, an abnormal granular cell layer, and epidermolytic hyperkeratosis, albeit none were statistically signficant predictors of PRP over psoriasis. Nevertheless, their identification emphasizes the varied histologic spectrum of PRP. The almost ubiquitous finding of acantholysis and the presence of an abnormal granular cell layer in many biopsies of PRP suggests that abnormal keratins or defects in the retinol signalling pathway may be of pathogenetic importance.

Idiopathic perniosis and its mimics: a clinical and histological study of 38 cases

Perniosis is a term applied to cold-induced painful or pruritic erythematous or violaceous acral papular or nodular lesions. We examined 39 skin biopsies from 38 patients who presented with acral purpuric lesions, suggesting a diagnosis of perniosis clinically or pathologically. The presence of a systemic or extracutaneous disease was established in 17 patients, including 5 with systemic lupus erythematosus (SLE), 3 with antiphospholipid antibodies, in 1 in whom there was underlying HIV disease, 2 with viral hepatitis, 2 with rheumatoid arthritis (RA), 2 with cryofibrinogenemia, 1 with hypergammaglobulinemia, 1 with iritis, and 1 with Crohn's disease. In the other 21 patients, the clinical presentations prompted further studies in 12, which showed a positive antinuclear antibody (ANA) in 10. A diagnosis of idiopathic perniosis (IP) was rendered in all 21 of these patients including those in whom a positive ANA was discovered, based on the absence of any other serological markers, signs, or symptoms indicative of a specific systemic disease complex; many had Raynaud's phenomenon, small joint arthralgias, atopy, or a family history of either connective tissue disease or Raynaud's disease. The histopathology of IP comprised a superficial and deep angiocentric lymphocytic infiltrate with papillary dermal edema and lymphocytic exocytosis directed to retia and acrosyringia. A few cases showed a mild vacuolopathic or lichenoid interface dermatitis, adventitial dermal mucinosis, lymphocytic eccrine hidradenitis, vascular ectasia, and thrombosis confined to dermal papillae capillaries. The biopsies from patients with iritis, RA, and Crohn's disease showed a granulomatous vasculitis and a granuloma annulare-like tissue reaction. The biopsies from the patients with SLE, cryofibrinogenemia, primary antiphospholipid antibody syndrome, and hypergammaglobulinemia shared a similar histopathology comprising an interface dermatitis, superficial and deep angiocentric and eccrinotropic lymphocytic infiltrates, vascular ectasia, and dermal mucinosis with prominent involvement of the eccrine coil. Many cases did not show features of IP, namely papillary dermal edema, thrombosis of dermal papillary capillaries, and lymphocytic exocytosis into the retia and acrosyringia. There was frequent vascular fibrin deposition involving reticular dermal vessels. The latter two variables were statistically significant discriminators between IP and in perniotic lesions observed in the setting of underlying systemic disease. With respect to the latter, some cases occurred in the setting of cold exposure and were designated by us as "secondary perniosis" (SP), whereas others showed no specific association with cold exposure and were designated as perniotic mimics (PMs) based exclusively on the gross and microscopic morphology of the lesions.

Skin reactions to hydroxyzine

Sensitivity to histamine H1-antagonists has mainly been observed with phenothiazine and ethylenediamine, and is very rare with hydroxyzine. We report 3 cases of sensitization to hydroxyzine, which was prescribed to treat urticaria and atopic dermatitis. A generalized maculopapular eruption appeared shortly after taking the drug. Patch tests with Atarax tablet were positive +3, and +2 or +3 with different dilutions of hydroxyzine. Patch tests with ethylenediamine, piperazine and other antihistamines were negative; therefore, there is no cross-allergy. We believe these rapid systemic reactions to hydroxyzine after the initial dose may have been due to prior systemic sensitivity to this drug, which cannot be used topically. Allergy to antihistamines must be considered when cutaneous lesions worsen on such therapy.

Subacute cutaneous lupus erythematosus arising in the setting of calcium channel blocker therapy

After 6 months to 5 years of calcium channel blocker (CCB) therapy for arterial hypertension, nine patients developed photoinduced annular or papulosquamous eruptions consonant clinically with subacute cutaneous lupus erythematosus (SCLE). Four patients were receiving diltiazem, four received verapamil, and one was taking nifedipine. Serology showed antinuclear antibodies (ANA) in seven of nine patients, anti-Ro antibodies in five, and anti-La antibodies in five, with three patients having only anti-La antibodies. Skin biopsy specimens in all nine patients were held to be characteristic of SCLE based on light microscopy, direct, and indirect immunofluorescence. The CCB was discontinued in all; in 8 patients in whom the CCB was stopped, the eruption resolved. A proposed mechanism by which the CCBs may have precipitated the eruptions is offered.

Drug-induced pseudolymphoma and drug hypersensitivity syndrome (Drug Rash with Eosinophilia and Systemic Symptoms: DRESS)

Since the first description by Saltzstein in 1959, the denomination of drug-induced pseudolymphoma was used to describe two cutaneous adverse drug reactions with a histological picture mimicking malignant lymphoma. On the basis of clinical presentation, this term includes two different patterns: (1) hypersensitivity syndrome which begins acutely in the first 2 months after the initiation of the drug and associates fever, a severe skin disease with characteristic infiltrated papules and facial edema or an exfoliative dermatitis, lymphadenopathy, hematologic abnormalities (hypereosinophilia, atypical lymphocytes) and organ involvement such as hepatitis, carditis, interstitial nephritis, or interstitial pneumonitis. The cutaneous histological pattern shows a lymphocytic infiltrate, sometimes mimicking a cutaneous lymphoma, and the mortality rate is about 10%. When organ involvement exists, corticosteroids are often prescribed with dramatic improvement. Relapses may occur. (2) drug-induced pseudolymphoma which has a more insidious beginning with nodules and infiltrated plaques appearing several weeks after the beginning of the drug without constitutional symptoms. A pseudolymphoma pattern is seen on cutaneous histological slides. Complete improvement is usual after drug withdrawal, but a delayed lymphoma is possible. To decrease the ambiguity of the denomination of hypersensitivity syndrome, we propose the term of DRESS (Drug Rash with Eosinophilia and Systemic Symptoms).

Drug-induced immune dysregulation as a cause of atypical cutaneous lymphoid infiltrates: a hypothesis

The authors encountered 22 patients in whom a skin biopsy showed atypical lymphoid hyperplasia and in whom a subsequent drug history showed indigestion of one or more agents before lesional onset. In 13 patients, the biopsy had been performed to rule out a diagnosis of malignant lymphoma, whereas the other nine the clinical impression was that of a drug eruption. Among the more frequently prescribed agents were calcium-channel blockers, angiotensin-converting enzyme (ACE) inhibitors, antidepressants, antihistamines, beta-blockers, benzodiazepines and lipid-lowering agents, all of which are either known to perturb lymphocyte function or have been implicated as a cause of pseudolymphomata. Twelve of the patients were on two or more of these drugs. The effect of drug modulation on the clinical course was assessed. The clinical presentations were as one or more erythematous plaques or multiple infiltrative papules, or as solitary nodules. The patient had been on one or more of the aforementioned drugs from 2 weeks to 5 years before developing the lesions. Resolution of the eruptions occurred in 17 patients within 1 to 32 weeks (mean, 7 weeks) of discontinuing the medication. Five additional patients had complete excision of solitary lesions without recurrence. A history of atopy, autoimmune disease, or previous carcinoma was elicited in five patients. All biopsy specimens showed atypical lymphoid infiltrates, which assumed one or more of the following patterns: mycosis fungoides (MF)-like, a lymphomatoid vascular reaction, lymphocytoma cutis and follicular mucinosis. Based on the histopathology of the biopsied lesions and the clinical course being one of lesional resolution after cessation of drug therapy or excision of a solitary lesion without subsequent recurrence, a diagnosis of drug-associated lymphomatoid hypersensitivity was established in all specimens. A diagnosis of drug-associated pseudolymphoma should be excluded before a diagnosis of cutaneous lymphoma is rendered, and should be considered if the patient is on a drug known to alter lymphocyte function, particularly in the setting of systemic immune dysregulation or multidrug therapy where agent may act synergistically or cumulatively to alter lymphoid function. The authors postulate that the drug may promote an aberrant immune response to an antigen that may be the drug itself or some other stimulus. A skin biopsy may be particularly helpful, as the lesions of drug-associated pseudolymphoma have a morphology distinctive from malignant lymphoma.