Histomorphology and Immunophenotype of Eczematous Skin Lesions Revisited—Skin Biopsies Are Not Reliable in Differentiating Allergic Contact Dermatitis, Irritant Contact Dermatitis, and Atopic Dermatitis

Epidermal spongiotic Langerhans cell collections, but not eosinophils, are a clue to the diagnosis of allergic contact dermatitis: A series of 170 clinically- and patch test-confirmed cases

BACKGROUND

Allergic contact dermatitis cannot be reliably differentiated from other forms of spongiotic/eczematous dermatitis by histology alone. Textbooks and recent studies have variably supported the specificity of dermal eosinophils, eosinophilic spongiosis, and Langerhans cell collections, among other features.

OBJECTIVE

To assess which histopathologic features favor a diagnosis of allergic contact dermatitis.

METHODS

In this case control study with prospective validation, patients were evaluated by patch testing and skin biopsy. Lesional histopathologic features were independently assessed.

RESULTS

One hundred seventy cases fulfilled inclusion criteria. Langerhans cell collections were more likely to be found in allergic contact dermatitis (29/111, 26%) (P = .03). Heavy dermal eosinophilic infiltration was associated with diagnoses other than allergic contact dermatitis. No significant differences were found for any other predictor variables.

LIMITATIONS

Mostly retrospective study with small validation sample.

CONCLUSION

This largest study to date is the first to independently confirm Langerhans cell collections as the single histopathologic feature most closely associated with allergic contact dermatitis.

Management of Atopic Hand Dermatitis

Atopic hand dermatitis (AHD), a manifestation of atopic dermatitis, can have a profound negative effect on a patient's disease-related quality of life due to its visibility, chronic nature, and overall discomfort that it causes. AHD differs from other forms of chronic hand eczema due to its likely distinct, complex pathogenesis, which is a combination of environmental triggers, genetic predisposition, and immune dysfunction. A proper diagnosis of AHD is made through clinical evaluation and the ability to establish subtle clinical differences between AHD and other conditions. Diagnosis is the first step to a treatment plan that diverges from a one-size-fits-all approach.

Contact Allergy Screening for Atopic Dermatitis

Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are common inflammatory skin diseases in both children and adults that present similarly and often coexist. Patch testing is the gold standard for establishing the diagnosis of ACD and can often help distinct between the 2 conditions. Patch testing is more challenging in patients with underlying AD due to potential for angry back reactions. In this review, we discuss the current evidence and guidelines regarding the screening for contact allergies in patients with AD. We also discuss the most frequent relevant allergens in adults and children with atopic dermatitis.

Disease burden, clinical management and unmet treatment need of patients with moderate to severe atopic dermatitis; consensus statements, insights and practices from CERTADE (Central/Eastern EU, Russia, Turkiye AD Experts) Delphi panel

Background

There is limited insight into the current disease burden and everyday clinical management of moderate-to- severe AD in Poland, Czechia, Russia, and Turkiye. Therefore, this study aimed to get information-driven insights regarding the current disease burden and clinical management of patients with moderate-to-severe AD with common and differentiating aspects of the patient journey and establish a consensus.

Methods

In this modified 2-round Delphi panel, 133 questions were asked in total to 27 dermatologists. A consensus was achieved when 70% of the panel members strongly agreed or agreed (or strongly disagreed or disagreed) with an item. Statements with <40% agreement dropped from the Delphi rounds and were not repeated.

Results

The results state that AD has a significant impact on the quality of life for both patients and their families with social and economic consequences in these countries. While there were significant dissimilarities regarding the current treatment approach by preference order and treatment duration among participants, there was also a high percentage of consensus on literature and guideline-based statements. Current topical therapies and the immune response modifiers were not found to be sufficient by panelists to cover the therapeutic needs of patients with moderate-to-severe AD. Moreover, panelists highlighted the significant burden of adverse events with the off-label use of currently available immunosuppressants.

Conclusions

These results underlined that there is a significant disease burden with an unmet treatment need for patients with moderate-to-severe AD in Poland, Czechia, Russia, and Turkiye.

Allergic Contact Dermatitis in Pediatric Practice

BACKGROUND

Allergic contact dermatitis (ACD) is prevalent among pediatric population, adolescent and young adults. Patients with ACD experience a lot of sociopsychological and qualityof- life (QoL) difficulties. Children and their caregivers alike are vulnerable to the burden of ACD.

OBJECTIVES

We have, in this paper, provided an overview of ACD and discussed common and unusual causes of ACD.

METHODS

We performed an up-to-date literature review in the English language on "allergic contact dermatitis" via PubMed Clinical Queries, using the keywords "allergic contact dermatitis" in August 2022. The search included meta-analyses, randomized controlled trials, clinical trials, casecontrol studies, cohort studies, observational studies, clinical guidelines, case series, case reports, and reviews. The search was restricted to English literature and children.

RESULTS

ACD may be acute or chronic and it affects more than 20% of children and adults with significant quality-of-life impairments. ACD is manifested by varying degrees of cutaneous edema, vesiculation, and erythema. The hypersensitivity reaction is one of the most prevalent forms of immunotoxicity in humans. Localized acute ACD lesions can be managed with high-potency topical steroids; if ACD is severe or extensive, systemic corticosteroid therapy is often required to provide relief within 24 hours. In patients with more severe dermatitis, oral prednisone should be tapered over 2-3 weeks. Rapid discontinuation of corticosteroids can result in rebound dermatitis. Patch testing should be performed if treatment fails and the specific allergen or diagnosis remains unknown.

CONCLUSION

ACD is common and can be a physically, psychologically, and economically burdensome disease. Diagnosis of ACD is primarily based on history (exposure to an allergen) and physical examination (morphology and location of the eruption). Skin patch test can help determine the causative allergen. Allergen avoidance is the cornerstone of management. Topical mid- or highpotency corticosteroids are the mainstay of treatment for lesions on less than 20% of the body area. Severe cases of ACD may require treatment with systemic corticosteroids.

The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

Machine learning for classification of cutaneous sebaceous neoplasms: implementing decision tree model using cytological and architectural features

BACKGROUND

This observational study aims to describe and compare histopathological, architectural, and nuclear characteristics of sebaceous lesions and utilized these characteristics to develop a predictive classification approach using machine learning algorithms.

METHODS

This cross-sectional study was conducted on Iranian patients with sebaceous tumors from two hospitals between March 2015 and March 2019. Pathology slides were reviewed by two pathologists and the architectural and cytological attributes were recorded. Multiple decision tree models were trained using 5-fold cross validation to determine the most important predictor variables and to develop a simple prediction model.

RESULTS

This study assessed the characteristics of 123 sebaceous tumors. Histopathological findings, including pagetoid appearance, neurovascular invasion, atypical mitosis, extensive necrotic area, poor cell differentiation, and non-lobular tumor growth pattern, as well as nuclear features, including highly irregular nuclear contour, and large nuclear size were exclusively observed in carcinomatous tumors. Among non-carcinomatous lesions, some sebaceoma and sebaceous adenoma cases had features like high mitotic activity, which can be misleading and complicate diagnosis. Based on multiple decision tree models, the five most critical variables for lesion categorization were identified as: basaloid cell count, peripheral basaloid cell layers, tumor margin, nuclear size, and chromatin.

CONCLUSIONS

This study implemented a machine learning modeling approach to help optimally categorize sebaceous lesions based on architectural and nuclear features. However, studies of larger sample sizes are needed to ensure the accuracy of our suggested predictive model.

Diseases from the Spectrum of Dermatitis and Eczema: Can "Omics" Sciences Help with Better Systematics and More Accurate Differential Diagnosis?

Researchers active in the field of inflammatory skin diseases from the spectrum of dermatitis and eczema are well aware of a considerable overlap in the clinical pictures and proposed sets of diagnostic criteria for these diseases, which can hardly be overcome through the clinical or epidemiological research. In effect, patients are included in studies based on vague and overlapping criteria, while heterogeneous study populations may, in turn, lead to non-representative outcomes and continued confusion. In this narrative review, a systematics of diseases from the spectrum of dermatitis and eczema is proposed based on the origins of causative factors and the pathomechanisms involved. Difficulties in differentiating between these diseases are discussed, and the extent to which advances in the "omics" sciences might help to overcome them is considered. Of all the "omics" research in this field, more than 90% of the published papers were devoted to atopic dermatitis, with a striking underrepresentation of other diseases from the spectrum of dermatitis and eczema, conditions which collectively exceed the rates of atopic dermatitis by far. A greater "omics" research effort is urgently needed to tackle other dermatitides, like allergic, irritant and protein contact dermatitis, as well as radiation, seborrheic, stasis or autoimmune dermatitis. Atopic dermatitis findings should be validated not only against healthy donors but also other dermatitides. A clinic-oriented approach is proposed for future "omics" studies in the field of dermatitis and eczema.

Investigation of Adverse Reactions in Tattooed Skin through Histological and Chemical Analysis

BACKGROUND

Just as the number of tattooed people has increased in recent years, so has the number of adverse reactions in tattooed skin. Tattoo colourants contain numerous, partly unidentified substances, which have the potential to provoke adverse skin reactions like allergies or granulomatous reactions. Identification of the triggering substances is often difficult or even impossible.

METHODS

Ten patients with typical adverse reactions in tattooed skin were enrolled in the study. Skin punch biopsies were taken and the paraffin-embedded specimens were analysed by standard haematoxylin and eosin and anti-CD3 stainings. Tattoo colourants provided by patients and punch biopsies of patients were analysed with different chromatography and mass spectrometry methods and X-ray fluorescence. Blood samples of 2 patients were screened for angiotensin-converting enzyme (ACE) and soluble interleukin-2 receptor (sIL-2R).

RESULTS

Histology showed variable skin reactions such as eosinophilic infiltrate, granulomatous reactions, or pseudolymphoma. CD3+ T lymphocytes dominated the dermal cellular infiltrate. Most patients had adverse skin reactions in red tattoos (n = 7), followed by white tattoos (n = 2). The red tattooed skin areas predominantly contained Pigment Red (P.R.) 170, but also P.R. 266, Pigment Orange (P.O.) 13, P.O. 16, and Pigment Blue (P.B.) 15. The white colourant of 1 patient contained rutile titanium dioxide but also other metals like nickel and chromium and methyl dehydroabietate - known as the main ingredient of colophonium. None of the 2 patients showed increased levels of ACE and sIL-2R related to sarcoidosis. Seven of the study participants showed partial or complete remission after treatment with topical steroids, intralesional steroids, or topical tacrolimus.

CONCLUSIONS

The combination of the methods presented might be a rational approach to identify the substances that trigger adverse reactions in tattoos. Such an approach might help make tattoo colourants safer in the future if such trigger substances could be omitted.

Allergic contact dermatitis of the eyelids: An interdisciplinary review

PURPOSE

A review of the published literature on the pathogenesis and treatment of eyelid allergic contact dermatitis and ocular surface involvement.

METHODS

Literature search of MEDLINE (Ovid) was conducted using for allergic contact dermatitis and disease of the eyelid or periorbital skin. Dates included in search criteria were from January 1, 2010 to January 12, 2023. 120 articles were reviewed by at least two authors.

RESULTS

Allergic eyelid contact dermatitis(ACD) is a Type IV hypersensitivity reaction to chemical exposure of sensitized eyelid skin. Most patients improve with avoidance strategies. Understanding chemicals that may trigger eyelid ACD, identifying allergens with patch testing, and use of topical steroids can help patients with this challenging disease.

CONCLUSIONS

Recalcitrant allergic eyelid dermatitis can be addressed by an interdisciplinary team and avoidance strategies based on patch testing.

Immunological Pathomechanisms of Spongiotic Dermatitis in Skin Lesions of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic pruritic skin disease with a complex pathogenesis underlying its heterogeneous clinical phenotypes and endotypes. The skin manifestation of AD reflects the cytokine milieu of a type-2-dominant immunity axis induced by genetic predisposition, innate immunity dysregulation, epidermal barrier defects, and allergic inflammation. However, the detailed pathomechanism of eczematous dermatitis, which is the principal characteristic of AD, remains unclear. This review examines previous studies demonstrating research progress in this area and considers the immunological pathomechanism of “spongiotic dermatitis”, which is the histopathological hallmark of eczematous dermatitis. Studies in this field have revealed the importance of IgE-mediated delayed-type hypersensitivity, the Fas/Fas-ligand system, and cell-mediated cytotoxicity in inducing the apoptosis of keratinocytes in spongiotic dermatitis. Recent studies have demonstrated that, together with infiltrating CD4 T cells, IgE-expressing dendritic cells (i.e., inflammatory dendritic epidermal cells and Langerhans cells) that capture specific allergens (i.e., house dust mites) are present in the spongiotic epidermis of lichenified eczema in patients with IgE-allergic AD. These findings suggest that IgE-mediated delayed-type hypersensitivity plays a pivotal role in the pathogenesis of spongiotic dermatitis in the skin lesions of AD.

Current emerging and investigational drugs for the treatment of chronic hand eczema

INTRODUCTION

: Chronic hand eczema (CHE) is a highly prevalent, burdensome condition associated with functional impairment. Currently, topical therapeutics are the mainstay of CHE management. However, many cases are refractory to existing topical therapeutics, and the few existing systemic options are often limited in efficacy and by their side effect profiles.

AREAS COVERED

: Following a brief overview of CHE pathogenesis and existing treatments, this review will outline the mechanisms and available data on emerging and investigational drugs currently being studied in clinical trials for the treatment of CHE.

EXPERT OPINION

: Immunomodulatory drugs such as topical and systemic JAK inhibitors and Th2-targeting antibodies such as dupilumab are currently under investigation for CHE treatment, with early promise. Management of CHE will likely move toward more targeted treatments through clinical trials and away from broad immunosuppressants such as cyclosporine and methotrexate, which have previously been investigated for CHE and have more side effects. In coming years, CHE patients may benefit from a wider range of both topical and systemic therapeutics that target immune pathways relevant to the various CHE subtypes.

Unique molecular signatures typify skin inflammation induced by chemical allergens and irritants

BACKGROUND

Skin exposure to chemicals may induce an inflammatory disease known as contact dermatitis (CD). Distinguishing the allergic and irritant forms of CD often proves challenging in the clinic.

METHODS

To characterize the molecular signatures of chemical-induced skin inflammation, we conducted a comprehensive transcriptomic analysis on the skin lesions of 47 patients with positive patch tests to reference contact allergens and nonallergenic irritants.

RESULTS

A clear segregation was observed between allergen- and irritant-induced gene profiles. Distinct modules pertaining to the epidermal compartment, metabolism, and proliferation were induced by both contact allergens and irritants; whereas only contact allergens prompted strong activation of adaptive immunity, notably of cytotoxic T-cell responses. Our results also confirmed that: (a) unique pathways characterize allergen- and irritant-induced dermatitis; (b) the intensity of the clinical reaction correlates with the magnitude of immune activation. Finally, using a machine-learning approach, we identified and validated several minimal combinations of biomarkers to distinguish contact allergy from irritation.

CONCLUSION

These results highlight the value of molecular profiling of chemical-induced skin inflammation for improving the diagnosis of allergic versus irritant contact dermatitis.

Immunohistopathological Analysis of Immunoglobulin E-Positive Epidermal Dendritic Cells with House Dust Mite Antigens in Naturally Occurring Skin Lesions of Adult and Elderly Patients with Atopic Dermatitis

The immunopathogenic role of house dust mite (HDM) allergens in the development of skin lesions in atopic dermatitis (AD) has not yet been precisely clarified. We immunohistopathologically evaluated the localization of immunoglobulin E (IgE)-positive epidermal dendritic cells with HDM antigens in the skin lesions of patients with IgE-allergic AD. Using double-immunofluorescence and single-immunochemical staining methods, we analyzed biopsy specimens from the skin lesions of six patients with IgE-allergic AD and HDM allergy and 11 control subjects with inflammatory skin disorders. Inflammatory dendritic epidermal cells (IDECs; CD11c+ and CD206+ cells) were markedly observed in the central area of the spongiotic epidermis of skin lesions in all AD patients. Furthermore, IgE-positive IDECs with HDM antigens in the central areas of the spongiosis were found in four of the six (66.7%) AD patients. Langerhans cells (LCs; CD207+ cells) with HDM antigens were also observed in the peripheral areas of the spongiosis. Infiltration of CD4+ and CD8+ T cells in association with IgE-positive IDECs and LCs with HDM antigens was seen in the spongiotic epidermis. An IgE-mediated delayed-type hypersensitivity reaction, in combination with IgE-bearing dendritic cells, specific T cells, keratinocytes, and HDM antigens, may lead to spongiotic tissue formation in eczematous dermatitis in AD.

Developing a standardized approach for assessing mast cells and eosinophils on tissue biopsies: A Work Group Report of the AAAAI Allergic Skin Diseases Committee

Mast cells and eosinophils are commonly found, expectedly or unexpectedly, in human tissue biopsies. Although the clinical significance of their presence, absence, quantity, and quality continues to be investigated in homeostasis and disease, there are currently gaps in knowledge related to what constitutes quantitatively relevant increases in mast cell and eosinophil number in tissue specimens for several clinical conditions. Diagnostically relevant thresholds of mast cell and eosinophil numbers have been proposed and generally accepted by the medical community for a few conditions, such as systemic mastocytosis and eosinophilic esophagitis. However, for other mast cell- and eosinophil-associated disorders, broad discrepancies remain regarding diagnostic thresholds and how samples are processed, routinely and/or specially stained, and interpreted and/or reported by pathologists. These discrepancies can obfuscate or delay a patient's correct diagnosis. Therefore, a work group was assembled to review the literature and develop a standardized consensus for assessing the presence of mast cells and eosinophils for a spectrum of clinical conditions, including systemic mastocytosis and cutaneous mastocytosis, mast cell activation syndrome, eosinophilic esophagitis, eosinophilic gastritis/enteritis, and hypereosinophilia/hypereosinophilic syndrome. The intent of this work group is to build a consensus among pathology, allergy, dermatology, hematology/oncology, and gastroenterology stakeholders for qualitatively and quantitatively assessing mast cells and eosinophils in skin, gastrointestinal, and bone marrow pathologic specimens for the benefit of clinical practice and patients.

What Is New in Occupational Allergic Contact Dermatitis in the Year of the COVID Pandemic?

PURPOSE OF REVIEW

This article aims to summarize some recent trends in occupational allergic contact dermatitis (ACD), including dermatitis related to pandemic-level personal protective equipment in healthcare workers, hazards patients may experience when working from home, and occupational perspectives on the recent American Contact Dermatitis Society (ACDS) allergens of the year and ACDS Core Allergen Series updates.

RECENT FINDINGS

Recent ACDS Allergens of the Year may be particularly relevant to healthcare workers, including isobornyl acrylate, which is present in glucose sensors and propylene glycol present in hand cleansers and disinfectants. Lavender, limonene, and linalool, all of which are new additions to the ACDS Core Allergen Series, have been reported as causes for occupational ACD in massage therapists and aromatherapists. Isothiazolinone allergy continues to rise in both consumer and occupational settings. Finally, the COVID-19 pandemic has resulted in a wave of occupational ACD in healthcare workers to personal protective equipment, and revealed new potential allergens for individuals working from home. Occupational allergic contact dermatitis continues to exert a significant occupational disease burden. Remaining aware of the current trends in allergens may allow for earlier recognition, diagnosis, and treatment, subsequently helping our patients to work in healthier and safer environments.

Ameliorative effects of total coumarins from the fructus of Cnidium monnieri (L.) Cuss. on 2,4-dinitrochlorobenzene-induced atopic dermatitis in rats

Atopic dermatitis (AD), which is characterized by intense pruritus and serious inflammation, is a chronic skin disease. Modern studies have testified that the total coumarins from the fructus of Cnidium monnieri (TCFC) possess evident biological activities based on their coumarin compounds. The purpose of this manuscript is to investigate the effects of topical use of TCFC on immune response, inflammation, and skin barrier function in rats with 2,4-dinitrochlorobenzene (DNCB)-induced AD. Results indicated that the skin lesion scores of rats were obviously reduced after the management of TCFC, and the spleen and thymus indices also were markedly repressed. TCFC significantly inhibited the overproduction of TNF-α, interferon-γ, interleukin (IL)-4, IL-13, thymic stromal lymphopoietin, and immunoglobulin E; the epidermal thickness and number of mast cells were notably decreased. The western blot experiment was conducted to determine the effects of TCFC on the mitogen-activated protein kinases signaling pathway. Results indicated that phosphorylation of extracellular signal-regulated kinases, p38, and c-Jun amino-terminal kinases was significantly blocked by TCFC. In addition, TCFC could upregulate the expression of filaggrin in dorsal skin, which means that TCFC showed a protective effect on skin barrier disruption. Furthermore, TCFC downregulated the levels of IL-1β, IL-4, IL-31, and TSLP mRNA and upregulated the expression of filaggrin mRNA in the dorsal skin of rats. Our research demonstrated the ameliorative effects of TCFC on AD-like rats by inhibiting immune response and inflammation and recovering skin barrier function.

A review of contact dermatitis

OBJECTIVE

To familiarize the reader with the mechanisms and causes of contact dermatitis.

DATA SOURCES

Recent research articles, relevant review articles, and case series/reports in English from PubMed database, mostly from 2010 onwards.

STUDY SELECTIONS

Most data were in the form of retrospective studies. Efforts were made to include clinical trials; however, for newer allergens and data on biologics, case series and case reports were included. Older studies regarding the mechanism were included if they were of particular importance.

RESULTS

An understanding of this review should enable the reader to approach the patient with unknown dermatitis with a better understanding of the cause and management.

CONCLUSION

Clinical suspicion for relevant allergens combined with the interpretation of patch tests are important in the diagnosis and treatment of patients with contact dermatitis.

Chronic Hand Eczema Guidelines From an Expert Panel of the International Eczema Council

Background

Assessment of chronic hand eczema (CHE) is complex and warrants standardization.

Objective

We sought to guide clinicians on the assessment of CHE.

Methods

An electronic questionnaire regarding the diagnosis and assessment of CHE was completed by councilors (n=45) of the International Eczema Council, an international group of clinicians and researchers with expertise in CHE. The survey consisted of 52 statements for consensus.

Results

Overall, nine statements (17.3%) had strong, twenty-three (44.2%) moderate, 12 (23.1%) low, and 8 (15.4%) very low levels of agreement. Five statements had considerable disagreement, including the value of conducting a skin biopsy (62.2% disagreement), investigating for possible type 1 reactions (60.0%), conducting a fungal culture (44.4%), finding no history of relevant allergens and/or irritants (31.1%) in most or all cases, and performing patch testing irrespective of lesion location and morphology (28.9%). Agreement was generally highest among respondents from Europe (28.6–77.8% agreement), followed by Asia (7.1%–35.7% agreement), North America (0%–35.5% agreement), and other (0%–13.3% agreement).

Conclusions

There were substantial differences of agreement, suggesting there are many knowledge and/or practice gaps with respect to CHE. Future research is needed to inform evidence-based and/or consensus guidelines for CHE.

Not All Fun and Games: A Case Report of Contact Dermatitis Related to Slime and Play-Doh

Slime and Play-Doh have been gaining popularity among adolescents and preteens. Both are gooey, viscoelastic substances that can be morphed and molded into virtually anything imaginable. Slime can be made from several household products including school glue and borax, which have both been linked to cases of irritant and allergic contact dermatitis, conditions that historically involve activation of many immune-regulatory cells such as Langerhans' cells and T cells. We review the rising incidence of contact dermatitis related to Slime and Play-Doh, pathogenesis, and hallmark findings, along with several treatment options to help clinicians expediently diagnose and treat the condition.

CD44 expression in human skin: High expression in irritant and allergic contact dermatitis and moderate expression in psoriasis lesions in comparison with healthy controls

BACKGROUND

Previous research using animal models demonstrated that CD44 expression may contribute to directing inflammatory cells into skin lesions during inflammation development in allergic contact dermatitis (ACD).

OBJECTIVES

To examine CD44 expression in patients with ACD and irritant contact dermatitis (ICD), and to compare it to patients with psoriatic lesions and healthy controls' (HCs) skin.

METHODS

This study included 200 patients comprising four groups of 50 each: ACD, ICD, psoriasis vulgaris, and HCs. CD44 expression was determined by immunohistochemical analysis using an optical microscope, and the results were visualized semiquantitatively by determining the percentage of immunoreactive cells in the epidermis, dermis, and on lymphocytes.

RESULTS

The highest CD44 expression was found in ICD, followed by ACD, psoriasis vulgaris, and lastly, the HCs (P < .001). Epidermal CD44 expression was significantly higher in contact dermatoses (especially in ICD) compared with psoriasis and healthy skin (P < .001). Similarly, CD44 expression in the dermis and on lymphocytes was strongest in ICD, although less pronounced than in the epidermis.

CONCLUSIONS

Because significantly elevated CD44 expression in ICD might be related to its function in maintaining and preserving the skin barrier in affected patients, further research on disease pathogenesis and new treatment options is needed.

Cytologic Grading of Cutaneous Sebaceous Neoplasms: Does it Help to Differentiate Benign From Malignant?

Both architectural and cytologic characteristics are used to distinguish benign from malignant sebaceous neoplasms; however, specific cytopathologic features of sebocytes have not been well defined. The authors assessed architectural and cytological features of 63 sebaceous neoplasms [15 sebaceous hyperplasias, 12 sebaceomas, 16 sebaceous adenomas (SA), 14 sebaceous carcinomas (SC), and 6 ocular sebaceous carcinoma (OSC)] to investigate whether cytological grading may facilitate classification of lesions. Among other criteria, nuclear pleomorphism (size, nucleolar appearance, membrane irregularity, crowding, mitoses, and chromatin pattern) was assessed and 3 theoretical nuclear grades established. Immunohistochemistry for CK10, p16, adipophilin and ki67 was performed on 7 cases of each type of tumor. Most sebaceous neoplasms, except OSC, showed a bland architectural silhouette. However, SA, SC, and OSC revealed larger nuclei (≥14 μm in ≥50% of cases), evident to multiple nucleoli, membrane irregularity, coarse to clumped chromatin, and nuclear grade ≥2 (latter in ≥56% of cases); by contrast, sebaceous hyperplasia and sebaceomas showed smaller nuclei (≤10 μm in ≥50% of cases), smooth borders, inconspicuous nucleoli, fine chromatin, and grade 1 nuclei (latter in 100% of cases). In the setting of a well-circumscribed architecture, cytologic features gain importance in the classification of sebaceous neoplasms. Interestingly, cytologic similarities found in SA and SC may indicate a close relationship of both neoplasms.

[Skin biopsy of inflammatory skin diseases in childhood-when is it reasonable?]

Compared with adulthood, inflammatory skin diseases are relatively rarely biopsied in children. Apart from the invasiveness of the procedure, the required local anesthesia, and the risks of infection and scarring, the psychological trauma of the operation has a higher impact in childhood. If a biopsy is performed, expectations towards the dermatopathology report are high. However, the evaluation of biopsies taken from children is challenging for the dermatopathologist: on the one hand, because the biopsies are often tiny or just superficial shaves and, on the other hand, because criteria for evaluation have mostly been developed from findings in adult biopsy specimens. In children, the immune system is still in the process of maturation and, therefore, infiltrates in the skin may look different from those seen in adults; however, knowledge about that is very limited to date. Moreover, numerous rare genodermatoses may manifest themselves first in childhood and need to be considered in the differential diagnosis while experience with them is often limited. Starting from the clinical presentation, this article presents histopathological features of possible differential diagnoses in order to demonstrate the value or necessity of a skin biopsy in a pediatric patient. In addition, communication with parents and child, methods of local anesthesia and biopsy techniques will be considered.