Clonality in the setting of Sweet's syndrome and pyoderma gangrenosum is not limited to underlying myeloproliferative disease

The Neutrophilic Dermatoses, or the Cutaneous Expressions of Neutrophilic Inflammation

Acute febrile neutrophilic dermatosis, or Sweet syndrome, has been described in 1964 and is now considered as a prototypical condition of the group of the neutrophilic dermatoses. Since this time, many clinical conditions have been included in this group and a clinical-pathological classification in 3 subgroups has been proposed. Neutrophilic infiltrates can localize in all internal organs. This defines the neutrophilic disease, which induces difficult diagnostic and therapeutic problems. Autoinflammation is the main pathophysiological mechanism of the neutrophilic dermatoses. There is a special link between myeloid malignancies (leukemia and myelodysplasia) and the neutrophilic dermatoses.

From Histiocytoid Sweet Syndrome to Myelodysplasia Cutis: History and Perspectives

In 2005, a new histologic variant of Sweet syndrome (SS) has been described and termed histiocytoid SS (HSS). Clinically, patients had a typical SS, but on skin biopsy, the infiltrates were composed of immature nonblast myeloid cells. Nearly 50% of patients with HSS have myelodysplastic syndrome (MDS). HSS may be the first manifestation leading to the diagnosis of MDS. In 2015, a new category of myeloid dermatosis has been proposed, called myelodysplasia cutis, describing the specific skin infiltration by myelodysplastic cells in patients with MDS.

Characterisation of IL-1 family members in Sweet syndrome highlights the overexpression of IL-1β and IL-1R3 as possible therapeutic targets

Sweet syndrome (SS) as a prototypic neutrophilic dermatosis (NDs) shares certain clinical and histologic features with monogenic auto-inflammatory disorders in which interleukin (IL)-1 cytokine family members play an important role. This has led to the proposal that NDs are polygenic auto-inflammatory diseases and has fuelled research to further understand the role of IL-1 family members in the pathogenesis of NDs. The aim of this study was to characterise the expression of the IL-1 family members IL-1β, IL-36γ, IL-33 and IL-1R3 (IL-1RaP) in SS. The expression profile of IL-1β, IL-33, IL-36γ and their common co-receptor IL-1R3 was analysed by immunohistochemistry, in situ hybridisation and double immunofluorescence (IF) in healthy control skin (HC) and lesional skin samples of SS. Marked overexpression of IL-1β in the dermis of SS (p < 0.001), and a non-significant increase in dermal (p = 0.087) and epidermal (p = 0.345) IL-36γ expression compared to HC was observed. Significantly increased IL-1R3 expression within the dermal infiltrate of SS skin samples (p = 0.02) was also observed, whereas no difference in IL-33 expression was found between SS and HC (p = 0.7139). In situ hybridisation revealed a good correlation between gene expression levels and the above protein expression levels. Double IF identifies neutrophils and macrophages as the predominant sources of IL-1β. This study shows that IL-1β produced by macrophages and neutrophils and IL-1R3 are significantly overexpressed in SS, thereby indicating a potential pathogenic role for this cytokine and receptor in SS.

Cutaneous manifestations of inflammatory bowel disease: basic characteristics, therapy, and potential pathophysiological associations

Inflammatory bowel disease (IBD) is a chronic inflammatory disease typically involving the gastrointestinal tract but not limited to it. IBD can be subdivided into Crohn's disease (CD) and ulcerative colitis (UC). Extraintestinal manifestations (EIMs) are observed in up to 47% of patients with IBD, with the most frequent reports of cutaneous manifestations. Among these, pyoderma gangrenosum (PG) and erythema nodosum (EN) are the two most common skin manifestations in IBD, and both are immune-related inflammatory skin diseases. The presence of cutaneous EIMs may either be concordant with intestinal disease activity or have an independent course. Despite some progress in research on EIMs, for instance, ectopic expression of gut-specific mucosal address cell adhesion molecule-1 (MAdCAM-1) and chemokine CCL25 on the vascular endothelium of the portal tract have been demonstrated in IBD-related primary sclerosing cholangitis (PSC), little is understood about the potential pathophysiological associations between IBD and cutaneous EIMs. Whether cutaneous EIMs are inflammatory events with a commonly shared genetic background or environmental risk factors with IBD but independent of IBD or are the result of an extraintestinal extension of intestinal inflammation, remains unclear. The review aims to provide an overview of the two most representative cutaneous manifestations of IBD, describe IBD's epidemiology, clinical characteristics, and histology, and discuss the immunopathophysiology and existing treatment strategies with biologic agents, with a focus on the potential pathophysiological associations between IBD and cutaneous EIMs.

Clonal haematopoiesis and dysregulation of the immune system

Age-related diseases are frequently linked to pathological immune dysfunction, including excessive inflammation, autoreactivity and immunodeficiency. Recent analyses of human genetic data have revealed that somatic mutations and mosaic chromosomal alterations in blood cells - a condition known as clonal haematopoiesis (CH) - are associated with ageing and pathological immune dysfunction. Indeed, large-scale epidemiological studies and experimental mouse models have demonstrated that CH can promote cardiovascular disease, chronic obstructive pulmonary disease, chronic liver disease, osteoporosis and gout. The genes most frequently mutated in CH, the epigenetic regulators TET2 and DNMT3A, implicate increased chemokine expression and inflammasome hyperactivation in myeloid cells as a possible mechanistic connection between CH and age-related diseases. In addition, TET2 and DNMT3A mutations in lymphoid cells have been shown to drive methylation-dependent alterations in differentiation and function. Here we review the observational and mechanistic studies describing the connection between CH and pathological immune dysfunction, the effects of CH-associated genetic alterations on the function of myeloid and lymphoid cells, and the clinical and therapeutic implications of CH as a target for immunomodulation.

Characteristics of Sweet syndrome in patients with or without malignancy

Sweet syndrome is a neutrophilic dermatosis occasionally associated with malignancies. Due to its rarity, the clinical features of Sweet syndrome are still unclear. Thus, we aimed to analyze clinical features, treatment, and outcomes of these patients according to associated disease. We conducted a retrospective, longitudinal cohort study from January 2000 to August 2020. We reviewed the medical records of 52 patients with Sweet syndrome. The median age of patients was 57.5 years old (range, 17-84), and 48.1% were female. Of the 52 patients analyzed, 27 patients (51.9%) had malignancy-associated Sweet syndrome. Sweet syndrome was diagnosed concurrently with (N = 8), before (N = 5), and after (N = 14) the diagnosis of malignancy. The idiopathic Sweet syndrome was most common in the non-malignancy group (56.0%). Myelodysplastic syndrome was the most common malignancy associated with Sweet syndrome (47.6%). Leukopenia (p = 0.005), anemia (p < 0.001), and thrombocytopenia (p = 0.008) were significantly associated with malignancy. The majority of patients showed rapid improvement of symptoms after steroid administration. The symptoms of some patients with malignancy did not improve with steroid alone; however, their symptoms often improved when steroids were combined with a treatment for the associated malignancy. Relapse and aggravation of Sweet syndrome were common in the malignancy group. Sweet syndrome showed a broad spectrum of clinical features related to various diseases. Sweet syndrome often occurred as a paraneoplastic feature. Therefore, active systemic evaluation is needed in the first diagnosis of Sweet syndrome without clear etiology.

Neutrophilic Dermatoses: a Clinical Update

Purpose of Review

Neutrophilic dermatoses are defined by the presence of a sterile neutrophilic infiltrate on histopathology. This review focuses on the pathogenesis, epidemiology, clinicopathological features, diagnosis, and management of four disorders: Sweet syndrome, pyoderma gangrenosum, Behçet syndrome, and neutrophilic eccrine hidradenitis.

Recent Findings

Recent studies have provided insight into the complex pathogenesis of neutrophilic dermatoses. Evidence supports an intricate interplay of abnormal neutrophil function and inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic predisposition.

Summary

Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, and neoplastic disorders, as well as drug reactions. Emerging diagnostic and therapeutic frameworks identify an expanding role for biologic and targeted anti-inflammatory therapies.

Inflammatory and Immune Disorders Associated with Myelodysplastic Syndromes

Systemic auto-inflammatory or autoimmune diseases (SIADs) develop in up to a quarter of patients with myelodysplastic syndromes (MDS) or chronic myelomonocytic leukemia (CMML). With or without the occurrence of SIADs, the distribution of MDS subtypes and the international or CMML-specific prognostic scoring systems have been similar between MDS/CMML patients. Moreover, various SIADs have been described in association with MDS, ranging from limited clinical manifestations to systemic diseases affecting multiple organs. Defined clinical entities including systemic vasculitis, connective tissue diseases, inflammatory arthritis and neutrophilic diseases are frequently reported; however, unclassified or isolated organ impairment can also be seen. Although the presence of SIADs does not impact the overall survival nor disease progression to acute myeloid leukemia, they can help with avoiding steroid dependence and make associated adverse events of immunosuppressive drugs challenging. While therapies using steroids and immunosuppressive treatment remain the backbone of first-line treatment, increasing evidence suggests that MDS specific therapy (hypomethylating agents) and sparing steroids may be effective in treating such complications based on their immunomodulatory effect. The aim of this review was to analyze the epidemiological, pathophysiological, clinical and therapeutic factors of systemic inflammatory and immune disorders associated with MDS.

Pyoderma gangrenosum in hematologic malignancies: A systematic review

BACKGROUND

Pyoderma gangrenosum (PG) is a devastating neutrophilic dermatosis that may be associated with trauma or systemic diseases. The associations, characteristics, and temporal relationship of PG with hematologic malignancies are not well understood.

OBJECTIVE

We performed a systematic review of PG associated with hematologic malignancies using data from case reports, case series, and retrospective studies.

METHODS

We searched MEDLINE, EMBASE, Scopus, and Web of Science from each database's inception to December 12, 2018. Two reviewers independently selected studies and extracted data.

RESULTS

Two hundred seventy-nine publications met the inclusion criteria (340 cases). Myelodysplastic syndrome (MDS) was the most commonly reported hematologic malignancy associated with PG, followed by monoclonal gammopathy of undetermined significance and acute myeloid leukemia. The mean age of patients was 56.5 years, with males being more common. There was a predominance of the ulcerative PG subtype and multifocal distributions across all hematologic malignancies. The majority of MDS cases preceded PG, which was reversed for MGUS.

LIMITATIONS

The data were limited by reporting bias because PG subtypes rely on the rendered diagnosis reported. In addition, the classification for hematologic malignancies has evolved since 1978.

CONCLUSION

Patients with PG should be evaluated for hematologic malignancies, with MDS being the most common.

Neutrophilic Dermatoses Associated with Myeloid Malignancies

Neutrophilic dermatoses (ND) are a group of conditions characterized by an aseptic accumulation of polymorphonuclear leukocytes in the skin. Occurrence of ND in association with myeloid malignancies, mainly myelodysplastic syndrome and myelogenous acute leukemia, is not rare and is often associated with a poor prognosis. Recent findings have improved understanding of the pathophysiology of myeloid malignancy-associated ND. We review the clinical spectrum of myeloid malignancy-associated ND with an emphasis on recently identified mechanisms. Myeloid leukemia cells retain the potential for terminal differentiation into polymorphonuclear leukocytes in the skin. Many studies suggest a clonal link between myeloid malignancies and ND. Activation of autoinflammatory pathways (NOD-like receptor family pyrin domain-containing-3, Familial Mediterranean Fever Gene) in the clonal cells of myeloid disorders may also be involved in this setting.

Pyoderma gangrenosum - a guide to diagnosis and management

Pyoderma gangrenosum (PG) is a reactive non-infectious inflammatory dermatosis falling under the spectrum of the neutrophilic dermatoses. There are several subtypes, with 'classical PG' as the most common form in approximately 85% cases. This presents as an extremely painful erythematous lesion which rapidly progresses to a blistered or necrotic ulcer. There is often a ragged undermined edge with a violaceous/erythematous border. The lower legs are most frequently affected although PG can present at any body site. Other subtypes include bullous, vegetative, pustular, peristomal and superficial granulomatous variants. The differential diagnosis includes all other causes of cutaneous ulceration as there are no definitive laboratory or histopathological criteria for PG. Underlying systemic conditions are found in up to 50% of cases and thus clinicians should investigate thoroughly for such conditions once a diagnosis of PG has been made. Treatment of PG remains largely anecdotal, with no national or international guidelines, and is selected according to severity and rate of progression. Despite being a well-recognised condition, there is often a failure to make an early diagnosis of PG. This diagnosis should be actively considered when assessing ulcers, as prompt treatment may avoid the complications of prolonged systemic therapy, delayed wound healing and scarring.

Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Clonal neutrophil infiltrates in concurrent Sweet's syndrome and acute myeloid leukemia: A case report and literature review

Sweet's syndrome (SS), also known as acute febrile neutrophilic dermatosis is often associated with a hematological malignancy, especially acute myeloid leukemia (AML) and myeloid dysplasia syndrome. Histopathologically, SS is characterized by diffuse infiltrates in the upper dermis, predominantly consisting of mature neutrophils. The origin of neutrophils invading the skin remains unknown. Herein, we report a patient with concurrent acute monoblastic leukemia and SS who initially presented with discrete erythematous papules and nodules on the neck. Single nucleotide polymorphism (SNP) array and next generation sequencing (NGS) revealed a concordant fms-related tyrosine kinase-3 (FLT-3) gene mutation in the bone marrow and skin lesion, indicating that the neutrophilic infiltrates were clonally related to the underlying myeloid neoplasm. This is the first case report of concurrent SS and AML, in which SNP array and NGS analysis were applied to confirm the clonality of the neutrophilic infiltrates.

Neutrophilic dermatoses: Pathogenesis, Sweet syndrome, neutrophilic eccrine hidradenitis, and Behçet disease

Neutrophilic dermatoses are a heterogeneous group of inflammatory skin disorders that present with unique clinical features but are unified by the presence of a sterile, predominantly neutrophilic infiltrate on histopathology. The morphology of cutaneous lesions associated with these disorders is heterogeneous, which renders diagnosis challenging. Moreover, a thorough evaluation is required to exclude diseases that mimic these disorders and to diagnose potential associated infectious, inflammatory, and neoplastic processes. While some neutrophilic dermatoses may resolve spontaneously, most require treatment to achieve remission. Delays in diagnosis and treatment can lead to significant patient morbidity and even mortality. Therapeutic modalities range from systemic corticosteroids to novel biologic agents, and the treatment literature is rapidly expanding. The first article in this continuing medical education series explores the pathogenesis of neutrophilic dermatoses and reviews the epidemiology, clinical and histopathologic features, diagnosis, and management of Sweet syndrome, neutrophilic eccrine hidradenitis, and Behçet disease.

Sweet syndrome in patients with and without malignancy: A retrospective analysis of 83 patients from a tertiary academic referral center

BACKGROUND

Sweet syndrome is a neutrophilic dermatosis that may be categorized into classic, malignancy-associated, and drug-induced subtypes. Few studies have systematically analyzed this rare disorder.

OBJECTIVE

To describe the clinicopathologic characteristics and treatment of Sweet syndrome and identify characteristics associated with concurrent malignancy.

METHODS

We retrospectively reviewed patients with Sweet syndrome at the University of Pennsylvania from 2005 to 2015.

RESULTS

We identified 83 patients (mean age, 57 years; 51% male) with Sweet syndrome: 30% with the classic form, 44% with the malignancy-associated form, 24% with the drug-induced form in the setting of malignancy, and 2% with the drug-induced form. Acute myeloid leukemia was the most common malignancy (in 24 of 83 patients [29%]). Filgrastim was the most common medication (used in 8 of 83 patients [10%]). Leukopenia (P < .001), anemia (P = .002), thrombocytopenia (P < .001), absence of arthralgia (P < .001), and histiocytoid or subcutaneous histopathology (P = .024) were associated with malignancy (χ² test).

LIMITATIONS

This was a retrospective study that represents patients from a single tertiary academic referral center, which may limit its generalizability to other settings.

CONCLUSION

When caring for patients with Sweet syndrome, dermatologists should be aware of the potential association of leukopenia, anemia, thrombocytopenia, absence of arthralgia, and histiocytoid or subcutaneous histopathology with malignancy.

Clinicopathologic, Immunohistochemical, and Molecular Features of Histiocytoid Sweet Syndrome

Importance

Histiocytoid Sweet syndrome is a rare histopathologic variant of Sweet syndrome. The nature of the histiocytoid infiltrate has generated considerable controversy in the literature.

Objective

The main goal of this study was to conduct a comprehensive overview of the immunohistochemical phenotype of the infiltrate in histiocytoid Sweet syndrome. We also analyze whether this variant of Sweet syndrome is more frequently associated with hematologic malignancies than classic Sweet syndrome.

Design

This is a retrospective case series study of the clinicopathologic, immunohistochemical, and molecular features of 33 patients with a clinicopathologic diagnosis of histiocytoid Sweet syndrome was conducted in the dermatology departments of 5 university hospitals and a private laboratory of dermatopathology.

Main Outcome and Measures

The clinical, histopathological, immunohistochemical, and follow-up features of 33 patients with histiocytoid Sweet syndrome were analyzed. In some cases, cytogenetic studies of the dermal infiltrate were also performed. We compare our findings with those of the literature.

Results

The dermal infiltrate from the 33 study patients (20 female; median age, 49 years; age range, 5-93 years; and 13 male; median age, 42 years; age range, 4-76 years) was mainly composed of myeloperoxidase-positive immature myelomonocytic cells with histiocytoid morphology. No cytogenetic anomalies were found in the infiltrate except in 1 case in which neoplastic cells of chronic myelogenous leukemia were intermingled with the cells of histiocytoid Sweet syndrome. Authentic histiocytes were also found in most cases, with a mature immunoprofile, but they appeared to be a minor component of the infiltrate. Histiocytoid Sweet syndrome was not more frequently related with hematologic malignancies than classic neutrophilic Sweet syndrome.

Conclusions and Relevance

The dermal infiltrate of cutaneous lesions of histiocytoid Sweet syndrome is composed mostly of immature cells of myeloid lineage. This infiltrate should not be interpreted as leukemia cutis.

Pyoderma Gangrenosum: An Update on Pathophysiology, Diagnosis and Treatment

Pyoderma gangrenosum (PG) is a rare inflammatory neutrophilic disorder with prototypical clinical presentations. Its pathophysiology is complex and not fully explained. Recent information regarding the genetic basis of PG and the role of auto-inflammation provides a better understanding of the disease and new therapeutic targets. PG equally affects patients of both sexes and of any age. Uncontrolled cutaneous neutrophilic inflammation is the cornerstone in a genetically predisposed individual. Multimodality management is often required to reduce inflammation, optimize wound healing, and treat underlying disease. A gold standard for the management of PG does not exist and high-level evidence is limited. Multiple factors must be taken into account when deciding on the optimum treatment for individual patients: location, number and size of lesion/ulceration(s), extracutaneous involvement, presence of associated disease, cost, and side effects of treatment, as well as patient comorbidities and preferences. Refractory and rapidly progressive cases require early initiation of systemic therapy. Newer targeted therapies represent a promising pathway for the management of PG, and the main focus of this review is the management and evidence supporting the role of new targeted therapies in PG.

Disorders characterized by predominant or exclusive dermal inflammation

Some cutaneous inflammatory disorders are typified by a predominant or exclusive localization in the dermis. They can be further subdivided by the principal cell types into lymphocytic, neutrophilic, and eosinophilic infiltrates, and mixtures of them are also seen in a proportion of cases. This review considers such conditions. Included among the lymphoid lesions are viral exanthems, pigmented purpuras, gyrate erythemas, polymorphous light eruption, lupus tumidus, and cutaneous lymphoid hyperplasia. Neutrophilic infiltrates are represented by infections, Sweet syndrome, pyoderma gangrenosum, and hidradenitis suppurativa, as well as a group of so-called "autoinflammatory" dermatitides comprising polymorphonuclear leukocytes. Eosinophil-dominated lesions include arthropod bite reactions, cutaneous parasitic infestations, the urticarial phase of bullous pemphigoid, Wells syndrome (eosinophilic cellulitis), hypereosinophilic syndrome, and Churg-Strauss disease. In other conditions, eosinophils are admixed with neutrophils in the corium, with or without small-vessel vasculitis. Exemplary disorders with those patterns include drug eruptions, chronic idiopathic urticaria, urticarial vasculitis, granuloma faciale, and Schnitzler syndrome (chronic urticarial with a monoclonal gammopathy).

Acute promyelocytic leukemia-associated Sweet's syndrome mimicking an axillary abscess: A case report with review of literature

A subcutaneous painful left axillary nodule was clinically diagnosed as abscess. Fine-needle aspiration biopsy (FNAB) revealed smears full of mature neutrophils. Background was free of fibrinous necrotic material and degenerating and necrotic neutrophils, which is characteristic of abscess. No organisms were detectable on special staining, and culture was sterile. A cytological differential diagnosis of abscess or Sweet's syndrome (SS) was offered, and the latter was confirmed. SS, also known as acute febrile neutrophilic dermatosis, shows diffuse dermal neutrophilic infiltrate without vasculitis on biopsy. Our case is probably the first where SS was diagnosed on FNAB. SS is a differential diagnosis for painful skin nodules. FNAB smears of painful skin nodules that yield abundant neutrophils should be carefully evaluated for necrosis, fibrin and degenerated neutrophils. The absence of these in an appropriate clinical setting points towards a neutrophilic dermatosis like SS.

Pyoderma gangrenosum and Sweet syndrome: the prototypic neutrophilic dermatoses

Pyoderma gangrenosum, a dramatic ulcerative skin disease, and Sweet syndrome, a papular dermatosis, were described independently. It was subsequently shown that they share many characteristics, including clinical overlap and the frequent association with multisystemic disorders. The group of the neutrophilic dermatoses encompasses these two dermatoses, as well as other conditions having in common an aseptic neutrophilic infiltrate predominating in the epidermis and/or the dermis and/or the subcutis. Some patients also experience neutrophilic infiltrates in other organs, defining the neutrophilic disease. Recent research suggests that the neutrophilic dermatoses could be considered as the cutaneous expression of the autoinflammation, an aberrant hyperproduction of interleukin-1. Autoinflammation is responsible for monogenic diseases, and is also involved in the mechanism of many polygenic conditions, including the neutrophilic dermatoses.

Characteristics of Sweet Syndrome in patients with acute myeloid leukemia

INTRODUCTION

Sweet syndrome (SS) is associated with hematologic malignancies including acute myeloid leukemia (AML).

PATIENTS AND METHODS

Records of patients with AML treated at our institution were reviewed to identify those with SS. Patient characteristics, laboratory values, and cytogenetic and molecular abnormalities were retrospectively reviewed.

RESULTS

We identified 21 of 2178 (1%) AML patients who demonstrated clinical signs and symptoms, and histological features consistent with SS. Eleven patients (52%) were classified as AML with myelodysplasia-related features and 3 patients had therapy-related AML. Three patients had received treatment with granulocyte colony stimulation factor, 1 patient liposomal all-trans-retinoic acid, and 2 patients received hypomethylating agents before development of SS. Cytogenetic analysis revealed diploid karyotype in 7 patients (33%); -5/del(5q) in 8 patients (38%): 3 patients had -5/del(5q) as the sole abnormality and 5 patients had -5/del(5q) as part of complex cytogenetics; and complex cytogenetics in 5 patients (24%). Gene mutations in FMS-related tyrosine kinase-3 (FLT3) gene were identified in 7 of 18 evaluable patients (39%), including FLT3-internal tandem duplication in 4 patients and FLT3-D835 tyrosine kinase domain mutation in 3 patients.

CONCLUSION

SS occurs in 1% of AML patients; -5/del(5q) karyotype, FLT3 mutations, and AML with myelodysplasia-related features were more frequent among patients with SS.

Sweet's syndrome in a patient with haemophilia, HIV and hepatitis C infection

Sweet's syndrome is a rare skin condition associated with both drug treatment and a number of different disease processes including haematological malignancies, inflammatory conditions and HIV infection. In this case report, we present a patient with HIV, haemophilia and hepatitis C who presented to our team with significant thrombocytopaenia and Sweet's syndrome. We discuss the difficulties with diagnosis and management in the context of multiple co-morbidities and suggest that both hepatitis C and HIV may have been aetiologically involved by suppressing platelet production and also causing bone marrow-driven neutrophilic disease.

20q- clonality in a case of oral sweet syndrome and myelodysplasia

We report the case of a patient with myelodysplasia who had Sweet syndrome of the oral cavity. An atypical myeloid immunophenotype was present in the gingival biopsy specimen and in a concurrent bone marrow specimen. Fluorescence in situ hybridization performed on the gingival biopsy specimen demonstrated the same del(20q) cytogenetic abnormality present in the bone marrow, confirming the presence of a clonally related myeloid proliferation in both tissues. This is the first reported case of Sweet syndrome and myelodysplasia in which the chromosomal abnormality was identified in the neutrophilic infiltrate, confirming the neutrophilic infiltrate to be clonally related to the underlying myeloid neoplasm.

Alteration in the gene encoding protein tyrosine phosphatase nonreceptor type 6 (PTPN6/SHP1) may contribute to neutrophilic dermatoses

We have found a B2 repeat insertion in the gene encoding protein tyrosine phosphatase nonreceptor type 6 (PTPN6) in a mouse that developed a skin disorder with clinical and histopathological features resembling those seen in human neutrophilic dermatoses. Neutrophilic dermatoses are a group of complex heterogeneous autoinflammatory diseases that all demonstrate excessive neutrophil infiltration of the skin. Therefore, we tested the cDNA and genomic DNA sequences of PTPN6 from patients with Sweet's syndrome (SW) and pyoderma gangrenosum and found numerous novel splice variants in different combinations. Isoforms resulting from deletions of exons 2, 5, 11, and 15 and retention of intron 1 or 5 were the most common in a patients with a familial case of SW, who had a neonatal onset of an inflammatory disorder with skin lesions and a biopsy specimen consistent with SW. These isoforms were associated with a heterozygous E441G mutation and a heterozygous 1.7-kbp deletion in the promoter region of the PTPN6 gene. Although full-length PTPN6 was detected in all other patients with either pyoderma gangrenosum or SW, it was always associated with splice variants: a partial deletion of exon 4 with the complete deletion of exon 5, alterations that were not detected in healthy controls. The defect in transcriptional regulation of the hematopoietic PTPN6 appears to be involved in the pathogenesis of certain subsets of the heterogeneous group of neutrophilic dermatoses.

Dermatoses neutrofílicas: parte I

Os autores apresentam uma revisão das dermatoses neutrofílicas que possuem grande repercussão à saúde dos pacientes: síndrome de Sweet, pioderma gangrenoso, doença de Behçet e urticária neutrofílica. São discutidos, baseados nos resultados e conclusões de estudos relevantes publicados recentemente e na experiência dos autores, os principais aspectos clínicos, as importantes alterações histopatológicas e as opções para o manejo.

Unusual causes of cutaneous ulceration

Skin ulceration is a major source of morbidity and is often difficult to manage. Ulcers caused by an inflammatory cause or microvascular occlusion are particularly challenging in terms of diagnosis and treatment. The management of such ulcers requires careful assessment of associated systemic conditions and a thorough analysis of the ulcer's clinical and histologic findings. In this article, the authors discuss several examples of inflammatory ulcers and the approach to the diagnosis and treatment of these ulcers.

Sweet's syndrome in association with common variable immunodeficiency

Sweet's syndrome (SS), a rare reactive neutrophilic dermatosis, has been reported to occur in association with a variety of systemic disorders, categorized by von den Diesch into idiopathic, paraneoplastic, pregnancy and parainflammatory subgroups. The parainflammatory group has been well defined, and includes a wide spectrum of infectious triggers and disorders of immune dysregulation. To date, however, no cases of SS have been described in the context of common variable immunodeficiency (CVID). We report a case of paediatric-onset SS, previously reported as idiopathic, with a subsequent diagnosis of CVID.

Sweet's syndrome--a comprehensive review of an acute febrile neutrophilic dermatosis

Sweet's syndrome (the eponym for acute febrile neutrophilic dermatosis) is characterized by a constellation of clinical symptoms, physical features, and pathologic findings which include fever, neutrophilia, tender erythematous skin lesions (papules, nodules, and plaques), and a diffuse infiltrate consisting predominantly of mature neutrophils that are typically located in the upper dermis. Several hundreds cases of Sweet's syndrome have been published. Sweet's syndrome presents in three clinical settings: classical (or idiopathic), malignancy-associated, and drug-induced. Classical Sweet's syndrome (CSS) usually presents in women between the age of 30 to 50 years, it is often preceded by an upper respiratory tract infection and may be associated with inflammatory bowel disease and pregnancy. Approximately one-third of patients with CSS experience recurrence of the dermatosis. The malignancy-associated Sweet's syndrome (MASS) can occur as a paraneoplastic syndrome in patients with an established cancer or individuals whose Sweet's syndrome-related hematologic dyscrasia or solid tumor was previously undiscovered; MASS is most commonly related to acute myelogenous leukemia. The dermatosis can precede, follow, or appear concurrent with the diagnosis of the patient's cancer. Hence, MASS can be the cutaneous harbinger of either an undiagnosed visceral malignancy in a previously cancer-free individual or an unsuspected cancer recurrence in an oncology patient. Drug-induced Sweet's syndrome (DISS) most commonly occurs in patients who have been treated with granulocyte-colony stimulating factor, however, other medications may also be associated with DISS. The pathogenesis of Sweet's syndrome may be multifactorial and still remains to be definitively established. Clinical and laboratory evidence suggests that cytokines have an etiologic role. Systemic corticosteroids are the therapeutic gold standard for Sweet's syndrome. After initiation of treatment with systemic corticosteroids, there is a prompt response consisting of dramatic improvement of both the dermatosis-related symptoms and skin lesions. Topical application of high potency corticosteroids or intralesional corticosteroids may be efficacious for treating localized lesions. Other first-line oral systemic agents are potassium iodide and colchicine. Second-line oral systemic agents include indomethacin, clofazimine, cyclosporine, and dapsone. The symptoms and lesions of Sweet's syndrome may resolved spontaneously, without any therapeutic intervention; however, recurrence may follow either spontaneous remission or therapy-induced clinical resolution.