Necrotizing Sweet syndrome: a new variant of neutrophilic dermatosis mimicking necrotizing fasciitis

Necrotizing Sweet Syndrome of the Hand and Forearm in the Immediate Postoperative Period: Case Report

Necrotizing soft tissue infection (NSTI) is a feared and potentially morbid postoperative complication requiring prompt surgical intervention. Cutaneous conditions that mimic NSTI have been reported and rarely occur in the postoperative period. Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a dermatologic condition characterized by fever, neutrophil-predominant leukocytosis, and painful skin lesions. Necrotizing Sweet syndrome (NSS) is an aggressive variant that causes a clinical appearance of localized skin necrosis and histologic evidence of necrotic foci extending to the deep aspects of the soft tissues and involving fascia and/or skeletal muscle. Necrotizing Sweet syndrome can be easily mistaken for NSTI. Contrary to infection, Sweet syndrome and NSS are worsened by surgical intervention due to the phenomenon of pathergy and readily respond to corticosteroid treatment. We present the case of a 54-year-old woman who developed NSS following an uncomplicated fasciectomy for Dupuytren disease.

Sweet syndrome in pregnancy: A narrative review

The aim of this review is to increase obstetrician awareness of pregnancy-associated Sweet syndrome. Patients present with fever, leukocytosis, and skin eruption, which can mimic other infectious or inflammatory conditions, but do not respond to antibiotics. A search using PubMed, EMBASE, and Web of Science Core Collection was conducted to review all reported cases of pregnancy-associated Sweet syndrome, an acute febrile neutrophilic dermatosis occurring during pregnancy or postpartum. A total of 33 episodes among 30 patients were identified, with the majority (54.5% [18]) of cases occurring within the second trimester. Among the 30 patients, skin lesions most commonly affected the head and neck (73.3% [22]), with rare oral or ocular involvement. Leukocytosis was the most common laboratory finding, reported in 96.7% [29] of patients, with neutrophil predominance noted in 70.0% [21]. The diagnosis was confirmed for all patients with pathognomonic results of skin biopsies. Of the 27 cases detailing treatment, systemic corticosteroids were most frequently used (19 cases), followed by conservative management (seven cases), and dapsone (one case). The dapsone-treated patient and 15 of the 19 steroid-treated patients experienced resolution, but additional management strategies were required in the remaining four individuals. Spontaneous resolution occurred during pregnancy in six of the seven conservatively managed individuals, with one patient experiencing spontaneous abortion shortly after skin eruption at 10 weeks of gestation. No associated maternal deaths were reported. Obstetric complications of pregnancy-associated Sweet syndrome included endomyometritis, sterile placental abscesses, and abdominal wall necrosis. Delivery of healthy infants occurred in 24 of the 25 cases that presented fetal outcome, which included two infants who underwent medically indicated preterm deliveries.

Periorbital necrotizing sweet syndrome: A report of two cases mimicking necrotizing soft tissue infections

Purpose

Two cases are described of necrotizing Sweet syndrome (nSS), a rare variant of acute febrile neutrophilic dermatosis that mimics necrotizing soft tissue infections.

Observation

A 74-year-old female with myelodysplastic syndrome (MDS) presented with isolated periorbital nSS that closely mimicked necrotizing fasciitis (NF); she displayed pathergy to debridement, was exquisitely responsive to corticosteroids, and underwent successful first-stage reconstruction of the eyelid with full-thickness skin grafting. A second 40-year-old female patient with relapsed acute myelogenous leukemia (AML) presented with multifocal nSS most prominently involving the eyelid. Positive herpes zoster virus (HSV) PCR and bacterial superinfection complicated the diagnosis. She improved with chemotherapy for AML and corticosteroid therapy.

Conclusion

nSS is rare and a high level of clinical suspicion as well as an understanding of its distinguishing features is necessary to avoid undue morbidity. Identification of pathergy, histopathology, microbiology, and clinical context are critical to avoid misdiagnosis of infection.

Suspected coexistence of perianal necrotizing sweet syndrome in chronic myelomonocytic leukemia: A case report

BACKGROUND

Chronic myelomonocytic leukemia (CMML) complicated with Sweet syndrome (SS) is a rare hematological neoplasm. However, cases of concomitant development of perianal necrotizing SS (NSS) have not been reported.

CASE SUMMARY

We report a case of a 49-year-old male patient who underwent sequential procedures for hemorrhoids and perianal abscess. He developed postoperative incision infection and was referred to the department where the authors work. Initially, perianal necrotizing fasciitis secondary to incision infection after perianal abscess surgery was suspected. Despite receiving antibiotic therapy and undergoing surgical debridement, deeper necrotic areas formed in the patient's perianal wounds, accompanied by persistent high fever. Blood and fungal cultures yielded negative results. The final diagnosis was corrected to be CMML with suspected concomitant perianal NSS.

CONCLUSION

CMML with perianal NSS is a rare condition, often misdiagnosed as perianal abscess or perianal necrotizing fasciitis. Conventional antibiotic therapy and surgical debridement are ineffective in managing this condition.

Sweet Syndrome and Neutrophilic Dermatosis of the Dorsal Hands

Sweet syndrome is a rare cutaneous condition with a broad clinical differential diagnosis. It can be classified into 3 subtypes: classic, malignancy-associated, and drug-induced. There are numerous associated disorders and provoking medications. Uncommonly, it can present as a multiorgan disease and cause significant morbidity. Systemic corticosteroids are the gold standard of treatment and yield rapid improvements in both lesions and symptoms. Nonsteroidal therapies may be effective alternatives, although high-quality comparative data are lacking. Some treatments for Sweet syndrome have paradoxically been implicated in the induction of disease.

Neoplastic or inflammatory? A case report of Sweet syndrome with CD30+ cells in a patient with B-lymphoblastic leukemia

CD30+ cells are typically part of lymphoproliferative disorders but can also be seen in inflammatory dermatoses. We present a case of 47-year-old man with a history of B-lymphoblastic leukemia (B-ALL) who presented with fever, leukocytosis, and papulonodular skin lesions, involving the extremities and trunk. A punch biopsy specimen demonstrated papillary dermal edema with a neutrophilic and histiocytic infiltrate extending into the subcutis. The infiltrate also harbored scattered large cells that were positive for CD30 and demonstrated the immunohistochemical profile of monocytes. A diagnosis of histiocytoid Sweet syndrome with CD30+ cells was made. The case is unique, demonstrating a combination of Sweet syndrome variants with subcutis involvement, histiocytoid morphology, and large CD30+ cells. A prior history of B-ALL and immunohistochemical profile of monocytes with immature morphology broadened the differential diagnosis and added to the diagnostic challenge.

Periorbital Necrotizing Sweet's Syndrome: A Case Report

Sweet's syndrome (acute febrile neutrophilic dermatosis) is an uncommon inflammatory condition most often associated with painful skin lesions of the head, neck, and upper extremities. To the authors' knowledge, this case report is the only published record of the necrotizing clinical variant of Sweet's syndrome in the periorbital space. This case follows a 91-year-old female who presented with generalized cutaneous eruptions of tender erythematous plaques, including a necrotic plaque of the left upper eyelid, and pancytopenia. A biopsy of an inner thigh lesion was consistent with Sweet's syndrome. Initially diagnosed with preseptal cellulitis, the patient experienced marked clinical improvement with corticosteroids. This, coupled with the histopathologic findings of her thigh biopsy and the absence of eyelid margins, led to the diagnosis of periorbital necrotizing Sweet's syndrome. Although cases of Sweet's syndrome in the periorbital region are rare, these diagnoses should not be overlooked and may be critical to patient care.

Necrotizing Fasciitis? A Mimic Produced by an Unusual Presentation of Necrotizing Neutrophilic Dermatosis of the Hand: A Case Report

CASE

A 50-year-old woman presented to our emergency department with hand pain and a laceration. Despite administration of antibiotics, the patient progressively worsened leading to a concern for a necrotizing soft-tissue infection. She underwent multiple debridements yet continued to worsen clinically. Tissue biopsy was eventually consistent with a necrotizing neutrophilic dermatosis. The patient was then started on oral steroids with rapid improvement of her clinical status and hand examination.

CONCLUSION

While neutrophilic dermatoses are rare, the orthopaedic surgeon treating soft-tissue infections should maintain a broad differential when treatment of a potential necrotizing infection has not led to diagnostic closure and clinical improvement.

Sweet Syndrome Associated with Myelodysplastic Syndrome-A Review of a Multidisciplinary Approach

Sweet syndrome (SS) is a rare disease described as a febrile neutrophilic dermatosis with acute onset, the pathogenesis of which has not yet been elucidated. The syndrome is characterized by the sudden onset of erythematous infiltrated papules or plaques located on the upper body and is associated with fever, leukocytosis and neutrophilia. The lesions show a dense dermal infiltration with mature neutrophils. The condition is responsive to systemic steroids. The central nervous system, bones, muscles, eyes, ears, mouth, heart, lung, liver, kidneys, intestines, and spleen may be affected by SS as extracutaneous manifestations. More and more cases have been found to be associated with malignancies, particularly myelodysplastic syndrome, and, less frequently, other hematologic malignancies or solid tumors. Approximately 21% of patients with SS have an associated malignancy and up to 80% of MASS cases are associated with hematological diseases, predominantly myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Myelodysplastic syndrome is a clonal disease of the bone marrow characterized by inefficient hematopoiesis, dysplasia of the bone marrow and peripheral cytopenias. Affected patients have a high risk of leukemic transformation. After analyzing later studies and current practical aspects regarding MDS-related SS, we suggest an algorithm for evaluating these patients.

Giant Cellulitis-like Sweet Syndrome Following Varicose Vein Surgery: A Rare Variant of Sweet Syndrome Mimicking Cellulitis

Giant cellulitis-like Sweet syndrome (GCS) is the most recently defined variant of Sweet syndrome (SS) which could clinically mimic wide-spreading cellulitis. Although there has been only paucity of reports in the literature, it mostly appears at lower half of the body and histologically shows dense infiltration of neutrophils with occasional histiocytoid mononuclear cells. Although its exact etiology has not been clarified, abnormal conditions (e.g., infection, malignancy and drugs) could be related triggering factors and trauma itself can be one of the causative elements as a 'pathergy phenomenon'. GCS could be confusing manifestation especially when appeared in postoperative condition. A 69-year-old female presented with an erythematous edematous papules and plaques on the right thigh after varicose vein surgery. Skin biopsy revealed diffuse neutrophilic infiltrates that was consistent with SS. To our knowledge, there has been no report of GCS as a postoperative complication after varicose vein surgery. Physicians should be aware of this uncommon reactive neutrophilic dermatoses mimicking infectious cutaneous disease.

Brain transplantation of genetically corrected Sanfilippo type B neural stem cells induces partial cross-correction of the disease

Sanfilippo syndrome type B (mucopolysaccharidosis type IIIB) is a recessive genetic disorder that severely affects the brain due to a deficiency in the enzyme α-N-acetylglucosaminidase (NAGLU), leading to intra-lysosomal accumulation of partially degraded heparan sulfate. There are no effective treatments for this disorder. In this project, we carried out an ex vivo correction of neural stem cells derived from Naglu -/- mice (iNSCs) induced pluripotent stem cells (iPSC) using a modified enzyme in which human NAGLU is fused to an insulin-like growth factor II receptor binding peptide in order to improve enzyme uptake. After brain transplantation of corrected iNSCs into Naglu -/- mice and long-term evaluation of their impact, we successfully detected NAGLU-IGFII activity in all transplanted animals. We found decreased lysosomal accumulation and reduced astrocytosis and microglial activation throughout transplanted brains. We also identified a novel neuropathological phenotype in untreated Naglu -/- brains with decreased levels of the neuronal marker Map2 and accumulation of synaptophysin-positive aggregates. Upon transplantation, we restored levels of Map2 expression and significantly reduced formation of synaptophysin-positive aggregates. Our findings suggest that genetically engineered iNSCs can be used to effectively deliver the missing enzyme to the brain and treat Sanfilippo type B-associated neuropathology.

A Case Report of Rapidly Necrotizing Fasciitis Post-Falling Down Treated Reconstructively

Necrotizing fasciitis (NF) is a necrotizing soft tissue infection that can result in fast tissue loss, necrosis, and potentially fatal acute sepsis. Diabetes, cancer, alcohol abuse, and chronic liver and renal disease are all risk factors for NF. In this case report, a 19-year-old man with a negative past medical and surgical history was diagnosed with aggressive rapidly progressive necrotizing fasciitis of the left lower extremity after a recent history of falling down from a skateboard. A successful treatment with long-term debridement surgeries followed by reconstructive surgery with skin grafting was made. Although the severity of this condition, the patient was able to resume a normal range of motion of the concerned extremity. NF has been described in the literature, but early diagnosis, which is crucial for successful management, rests a challenge.

Neutrophilic Dermatosis and Management Strategies for the Inpatient Dermatologist

Purpose of Review

Neutrophilic dermatoses are a heterogeneous group of disorders with significant overlap in associated conditions, clinical presentation, and histopathologic features. This review provides a structural overview of neutrophilic dermatoses that may present in the inpatient setting along with diagnostic work-up and management strategies.

Recent Findings

Sweet's syndrome has been found in patients with coronavirus disease 2019 (COVID-19). Pyoderma gangrenosum (PG) has been shown to be equally associated with ulcerative colitis and Crohn's disease. A clinical trial shows that cyclosporine is equally effective as prednisone in treating PG. Neutrophilic eccrine hidradenitis has been found in the setting of newer antineoplastic medications, such as BRAF inhibitors, as well as in the setting of malignancy without chemotherapy exposure.

Summary

Neutrophilic dermatoses are a rare and complex group of dermatoses with varying and overlapping clinical presentations. Physicians should be aware of the growing list of associated diseases in order to build a better differential diagnosis or to potentially investigate for co-existing disease.

A Case Report of Necrotizing Neutrophilic Dermatosis: A Sheep in Wolf's Clothing

Neutrophilic dermatosis (ND) is a category of diseases characterized by trauma-induced, autoinflammatory cutaneous eruption. Comorbid systemic disease is common with a predilection for malignancy, inflammatory bowel disease, and rheumatologic disease. Rarely, it can manifest with aseptic shock, an entity referred to as necrotizing neutrophilic dermatosis (NND). NND may occur in the postoperative setting and is often misdiagnosed as a necrotizing soft tissue infection. Unfortunately, the treatment for a necrotizing soft tissue infection, namely, wide debridement, is often detrimental in the setting of NND. We present the case of a woman with underlying myelodysplastic syndrome who developed episodic postoperative hemodynamic collapse followed by delayed necrotic peristomal ulceration following colonic diversion for complicated diverticulitis. Infectious workup and operative re-exploration were unrevealing. Pathologic assessment of affected skin tissue showed changes consistent with ND, ultimately leading to the diagnosis of NND. Her clinical course dramatically improved with the initiation of immunosuppressive therapy. The mimicry of NND to a potentially lethal necrotizing soft-tissue infection creates a grave diagnostic dilemma in the postoperative period. A general lack of knowledge of NND among non-dermatologic specialists produces an opportunity for misdiagnosis and inappropriate surgical interventions, namely, serial debridement. Several clinical cues may aid in the earlier recognition of NND. The cornerstone of treatment involves systemic corticosteroid therapy with adjunctive therapy for refractory cases. NND must be considered in the differential diagnosis of necrotizing soft tissue infection as early recognition may result in the avoidance of deleterious surgical interventions.

New Practical Aspects of Sweet Syndrome

Sweet syndrome (SS), or acute febrile neutrophilic dermatosis, is an inflammatory, non-infectious skin reaction characterized clinically by tender, erythematous papules/plaques/pustules/nodules commonly appearing on the upper limbs, trunk, and head and neck; histologically, SS is characterized by dense neutrophilic infiltrate in the dermis. SS is accompanied by fever; an elevation of inflammatory markers (e.g., erythrocyte sedimentation rate, C reactive protein) in serum may also be observed. Although most cases of SS are idiopathic, SS also occurs in the setting of malignancy or following administration of an associated drug. SS has also been reported in association with pregnancy and a burgeoning list of infectious (most commonly upper respiratory tract infections) and inflammatory diseases; likewise, the litany of possible iatrogenic triggers has also grown. Over the past several years, a wider spectrum of SS presentation has been realized, with several reports highlighting novel clinical and histological variants. Corticosteroids continue to be efficacious first-line therapy for the majority of patients with SS, although novel steroid-sparing agents have been recently added to the therapeutic armamentarium against refractory SS. New mechanisms of SS induction have also been recognized, although the precise etiology of SS still remains elusive. Here, we catalogue the various clinical and histological presentations of SS, summarize recently reported disease associations and iatrogenic triggers, and review treatment options. We also attempt to frame the findings of this review in the context of established and emerging paradigms of SS pathogenesis.

Diagnosis of Sweet's syndrome in otolaryngology

Sweet's syndrome (acute febrile neutrophilic dermatosis) consists of acute onset of painful cutaneous erythematous lesions, mostly found in the upper extremities followed by the head and neck region, particularly in patients with underlying malignancies. We describe the case of a woman in her mid-30s, who was treated for acute myeloid leukaemia and presented with a severe painful and progressive erythematous lesion of the retroauricular skin. Clinical features, laboratory tests, blood cultures and histological biopsy yielded a diagnosis of Sweet's syndrome. The treatment consisted of oral and topical corticosteroids and her signs and symptoms resolved within 1 week. Although Sweet's syndrome is uncommon, awareness among otolaryngologists is crucial to ensure a prompt diagnosis, cure and referral to an oncologist (if not already involved) for patients with Sweet's syndrome in the head and neck area.

Skin and Soft Tissue Infections in Non-Human Immunodeficiency Virus Immunocompromised Hosts

Skin and soft tissue infections among the non-human immunodeficiency virus infected immunosuppressed population are a serious and growing concern. Many pathogens can cause cutaneous infections in these patients owing to the highly varied and profound immune deficits. Although patients can be infected by typical organisms, the diversity and antimicrobial-resistant nature of the organisms causing these infections result in significant morbidity and mortality. The diagnostic approach to these infections in immunocompromised hosts can differ dramatically depending on the potential causative organisms. An understanding of new immunosuppressive treatments and evolving antimicrobial resistance patterns are required to optimally manage these difficult cases.

Sweet's syndrome associated with hematological malignancies

BACKGROUND

Sweet's syndrome, or acute febrile neutrophilic dermatosis, is often mistaken for a skin infection given its similar clinical presentation.

OBJECTIVE

To describe the clinical presentations and management of a rare dermatologic condition associated with hematological malignancies.

METHODS

Case series; Chart review of patients at Moffitt Cancer Center between 2017 and 2020.

RESULTS

The subjects are a 79 year-old man (Patient 1) with Myelodysplastic Syndrome (MDS), a 66 year-old woman (Patient 2) with Acute Myeloid Leukemia (AML), a 56 year-old man (Patient 3) with AML, and a 69 year-old man (Patient 4) with MDS. Patient 1 was initially misdiagnosed with neutropenic fever. Patient 2 was incidentally discovered to have erythematous skin lesions prior to initiating chemotherapy. Before starting second line chemotherapy, patient 3 developed pathergy at the site of a PICC line. Patient 4 developed erythema around a newly placed port before initiating chemotherapy. Only patients 1 and 3 received glucocorticoids. Patients 2, 3, and 4 were able to initiate chemotherapy without further complications.

LIMITATIONS

Heterogeneity of subjects in terms of prognostic factors, stage at diagnosis, and treatment strategies.

CONCLUSION

Early recognition and treatment of malignancy-associated Sweet's syndrome is imperative to limit patient morbidity and expeditiously provide anti-cancer treatments.

Neutrophilic dermatoses with unusual and atypical presentations

Neutrophilic dermatoses (NDs) are a group of reactive, noninfectious autoinflammatory diseases characterized by (1) infiltration of the epidermis, dermis, and or/hypodermis by neutrophils; (2) their association with distinct diseases (eg, hematologic malignancy and chronic inflammatory diseases); (3) potential extracutaneous involvement; and (4) response to anti-inflammatory drugs, such as corticosteroids, dapsone, colchicine, and novel biologic therapies, such as the anti-interleukin-1 blockade. Although distinct NDs have been described, transitional forms with overlapping features are often identified. These justify a simplified classification of NDs with three major forms: superficial (epidermal or pustular) NDs, dermal (en plaques) NDs, and deep NDs. We review selected or novel variants of NDs, including subcorneal pustular dermatosis, the group of immunoglobulin A neutrophilic dermatoses, amicrobial pustular dermatosis of the folds, and neutrophilic urticarial dermatosis, as well as atypical forms of Sweet syndrome and pyoderma gangrenosum closely mimicking severe infectious diseases. Knowledge of these variants is essential for proper diagnosis, adequate management, and avoidance of a dangerous escalation of therapy, such as unnecessary immunosuppression or extensive surgery.

Necrotizing neutrophilic dermatosis: A diagnostic challenge with a need for multi-disciplinary recognition, a case report

Introduction

Necrotizing neutrophilic dermatoses can clinically resemble necrotizing fasciitis and therefore pose a diagnostic and therapeutic challenge. Given their similar presentations, misdiagnosis and inappropriate or delayed treatments are possible.

Presentation of case

We discuss the case of a woman with acute myeloid leukemia who presented with fevers, chills, cough, and a leg wound. She underwent amputation of her lower extremity after she was presumed to have necrotizing fasciitis; however, symptoms persisted. She was ultimately diagnosed with and treated for necrotizing Sweet's syndrome with notable clinical improvement.

Discussion

Both, necrotizing neutrophilic dermatoses and necrotizing fasciitis, grossly affect the skin and are associated with rapidly progressing systemic features including fevers, chills, leukocytosis, and elevated inflammatory markers. Recent literature in dermatology addresses these similarities and the appropriate approach to management; however, it is critical that medical and surgical subspecialties have an understanding of necrotizing neutrophilic dermatoses and their clinical presentations, diagnostic approaches, as well as therapeutic interventions. Familiarity with this entity can mitigate the risk of misdiagnosis, morbidity, and mortality.

Conclusion

With this report, we seek to review the features that are suggestive of and aid in the diagnosis of necrotizing neutrophilic dermatoses to help prevent significant and avoidable morbidity.

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Necrotizing neutrophilic dermatoses are a rare skin condition that can easily be misdiagnosed as necrotizing fasciitis.

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Providers from specialties like internal medicine, oncology, and surgery may encounter necrotizing neutrophilic dermatosis.

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Familiarity with the management of necrotizing neutrophilic dermatoses can reduce avoidable morbidity.

Genital Sweet's Syndrome in a patient with Acute Myelogenous Leukemia

A 71 year old male presented to the emergency room for evaluation of acute erythema, edema and pain of the penis and scrotum. There was initial concern for Fournier's gangrene, however labs were unremarkable and vital signs were stable. He did not improve with antibiotics. Biopsy results showed neutrophil infiltration consistent with Sweet's Syndrome. He was started on corticosteroids and discharged home in stable condition. In a hemodynamically stable patient not responding to antibiotic therapy, close observation is prudent until the tissue biopsy results.

Recurrent soft tissue inflammation, necrotizing fascitis or Sweet syndrome, diagnostic dilemma

Necrotizing Sweet syndrome is a recently described entity that can pose significant challenges for management. Although necrotizing fasciitis can be rapidly fatal in the absence of prompt surgical management, necrotizing Sweet syndrome may actually be worsened by any surgical intervention. Authors want to emphasize and increase awareness of this rare presentation.

Clinical Features of Neutrophilic Dermatosis Variants Resembling Necrotizing Fasciitis

Importance

Pyoderma gangrenosum and necrotizing Sweet syndrome are diagnostically challenging variants of neutrophilic dermatosis that can clinically mimic the cutaneous and systemic features of necrotizing fasciitis. Improved characterization of these rare variants is needed, as improper diagnosis may lead to inappropriate or delayed treatment and the potential for morbidity.

Objective

To determine the characteristics of necrotizing neutrophilic dermatosis to improve diagnostic accuracy and distinguish from infection.

Design, Setting, and Participants

A case series of patients with necrotizing neutrophilic dermatosis treated at 3 academic hospitals (University of California San Francisco, Oregon Health and Science University, and University of Minnesota) from January 1, 2015, to December 31, 2017, was performed along with a literature review of related articles published between January 1, 1980, and December 31, 2017. Data were obtained from medical records as well as Medline and Embase databases. All patients had signs resembling necrotizing infection and had a final diagnosis of pyoderma gangrenosum with systemic features or necrotizing Sweet syndrome. Patients were excluded if a diagnosis other than neutrophilic dermatosis was made, if key clinical information was missing, and if reported in a non-English language.

Main Outcomes and Measures

Description of key characteristics of necrotizing neutrophilic dermatosis.

Results

Overall, 54 patients with necrotizing neutrophilic dermatosis were included, of which 40 had pyoderma gangrenosum with systemic features and 14 had necrotizing Sweet syndrome. Of the 54 patients, 29 (54%) were male and 25 (46%) were female, with a mean (SD) age of 51 (19) years. Skin lesions commonly occurred on the lower (19 [35%]) and upper (13 [24%]) extremities and developed after a surgical procedure (22 [41%]) or skin trauma (10 [19%]). Shock was reported in 14 patients (26%), and leukemoid reaction was seen in 15 patients (28%). Of the patients with necrotizing neutrophilic dermatosis, 51 (94%) were initially misdiagnosed as necrotizing fasciitis and subsequently received inappropriate treatment. Debridement was performed in 42 patients (78%), with a mean (SD) of 2 (2 [range, 1-12]) debridements per patient. Four amputations (7%) were performed. Forty-nine patients (91%) received antibiotics when necrotizing neutrophilic dermatosis was misdiagnosed as an infection, and 50 patients (93%) received systemic corticosteroids; all patients responded to immunosuppressants.

Conclusions and Relevance

A complex spectrum of clinical findings of pyoderma gangrenosum and Sweet syndrome with prominent systemic inflammation exists that defines a new subset of neutrophilic dermatoses, termed necrotizing neutrophilic dermatoses; recognizing the difference between this variant and severe infection may prevent unnecessary surgical procedures and prolonged disease morbidity associated with a misdiagnosis and may expedite appropriate medical management.

Autoinflammatory Disorders: A Review and Update on Pathogenesis and Treatment

The autoinflammatory diseases comprise a broad spectrum of disorders characterized by unchecked activation of the innate immune system. Whereas aberrations in adaptive immunity have long been identified in 'autoimmune' disorders, the concept of 'autoinflammation' emerged relatively recently, first describing a group of clinical disorders characterized by spontaneous episodes of systemic inflammation without manifestations typical of autoimmune disorders. Improved knowledge of innate immune mechanisms, coupled with remarkable progress in genomics and an expanding number of clinical cases, has since led to an increasing number of disorders classified as autoinflammatory or containing an autoinflammatory component. Biologic therapies targeting specific components of the innate immune system have provided immense clinical benefit, and have further elucidated the role of innate immunity in autoinflammatory disorders. This article reviews the basic mechanisms of autoinflammation, followed by an update on the pathophysiology and treatment of the monogenic and multifactorial autoinflammatory diseases, and the common dermatologic conditions in which autoinflammation plays a major role.

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.

Sweet's syndrome: a clinical entity need to discriminate against acute haematogenous periprosthetic joint infection

Sweet's syndrome (SS) or acute febrile neutrophilic dermatosis is an uncommon condition. It is characterized by fever, polymorphonuclear leukocytosis, painful erythematous cutaneous plaques, and dense dermal infiltrate of neutrophils without vasculitis at the site of skin lesions. Lesions in SS might enlarge and coalesce with increasing dermal oedema, resulting in pseudo-vesicular appearance mimicking joint infections. Here, a rare case of SS mimicking acute haematogenous periprosthetic infection in a 74-year-old woman with a history of total knee arthroplasty is reported. This report aims to elaborate clinical various manifestations of SS in a patient with a history of total knee arthroplasty. In addition, this report describes how to discriminate inflammation between SS and periprosthetic joint infection. Level of evidence V.

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.

Necrotizing Sweet Syndrome of the Upper Extremity After Elective Hand Surgery

Sweet syndrome, or acute febrile neutrophilic dermatosis, is a systemic disease process mainly characterized by hyperpyrexia and skin lesions. A newly described entity, necrotizing Sweet syndrome, is a severe and locally aggressive dermatological condition that clinically and histopathologically resembles a necrotizing soft tissue infection. It is characterized by pathergy, a nonspecific inflammatory response to cutaneous trauma resulting in a propagation of the disease. In contrast to a necrotizing infection, this condition responds to systemic steroids. A high clinical suspicion is required in order to distinguish a necrotizing polymicrobial infection from noninfectious necrotizing Sweet syndrome. We present a case following elective hand surgery.

Inflammatory Dermatopathology for General Surgical Pathologists

Owing to the wide variety and complexity of inflammatory skin diseases, inflammatory dermatopathology can be a challenging topic for dermatopathologists and general surgical pathologists alike. Following a basic tissue reaction pattern approach, this article reviews the most common and important entities of each pattern, with emphasis on differential diagnosis, diagnostic pitfalls, and appropriate workup when indicated. A few dermatologic emergencies are also discussed.

Necrotizing Soft Tissue Infection or Sweet Syndrome: Surgery Versus No Surgery?: A Case Report

The authors report a case of necrotizing Sweet syndrome in a 24-year-old transsexual male who presented with recurrent myonecrosis of the neck/upper chest. On index admission, computer tomography revealed gas and fat stranding of the sternocleidomastoid and pectoralis major muscle-findings suggestive of a necrotizing soft tissue infection. Despite debridement procedures and intravenous antibiotic therapy, myonecrosis of the affected areas persisted. Evaluation of tissue samples by dermatopathology revealed neutrophilic infiltration extending into the dermis and muscle necrosis, findings consistent with necrotizing Sweet syndrome. The initiation of IV corticosteroids, the gold-standard treatment for necrotizing Sweet syndrome, lead to significant clinical improvement. When soft tissue infections do not respond to debridement and broad-spectrum antimicrobial coverage, perioperative care providers should consider necrotizing Sweet syndrome as an underlying cause. By facilitating the early diagnosis and appropriate management of unique conditions such as necrotizing Sweet syndrome, anesthesiologists can not only play a more visible role as leaders in the emerging perioperative surgical home model, but they may also prevent significant patient morbidity and reduce unnecessary utilization of health care resources.

Sweet Syndrome: A Review and Update

Sweet syndrome is the most representative entity of febrile neutrophilic dermatoses. It typically presents in patients with pirexya, neutrophilia, painful tender erytomatous papules, nodules and plaques often distributed asymmetrically. Frequent sites include the face, neck and upper extremities. Affected sites show a characteristical neutrophilic infiltrate in the upper dermis. Its etiology remains elucidated, but it seems that can be mediated by a hypersensitivity reaction in which cytokines, followed by infiltration of neutrophils, may be involved. Systemic corticosteroids are the first-line of treatment in most cases. We present a concise review of the pathogenesis, classification, diagnosis and treatment update of this entity.

Multi-organ involvement of Sweet's syndrome: a case report and literature review

The hallmark of Sweet's syndrome (SS) is the infiltration of mature neutrophils in the upper dermis. We herein report a case of SS with multi-organ involvement. A 32-year-old man presented with fever, anemia and dyspnea. He was given antibiotics, without any improvements. Later, a number of erythematous lesions appeared, accompanied by deteriorating respiratory and cardiovascular functions. A diagnosis of SS was confirmed on a skin biopsy, and the patient was given corticosteroids, the dose of which was reduced after one month. The organ function subsequently deteriorated, and he ultimately died of multi-organ failure. Early recognition of SS with multi-organ involvement is important in patients with SS.

Neutrophilic panniculitis: algorithmic approach to a heterogeneous group of disorders

CONTEXT

Neutrophilic panniculitis encompasses an etiologically and morphologically heterogeneous group of disorders. Correct histopathologic diagnosis is important in identifying certain systemic diseases and guiding appropriate treatment.

OBJECTIVE

To review the clinical and histopathologic features of different types of neutrophilic panniculitis, and to provide a diagnostic algorithm for these disorders.

DATA SOURCES

A review of the literature with emphasis on the distinguishing features of different entities was performed.

CONCLUSIONS

Evaluation for neutrophilic panniculitis entails paying close attention to the pattern of inflammation, the type of fat necrosis present, any evidence of vascular damage, and other relevant histopathologic features. An algorithmic approach integrating all histopathologic, clinical, and laboratory findings is required for correct diagnosis.

Noma and cervicofacial necrotizing fasciitis: clinicopathological differentiation and an illustrative case report of noma

Noma predominantly affects malnourished young children. The pathogenesis of noma is complex and multifactorial, involving interaction between local polybacterial infection on the one hand, and malnutrition, immunosuppression, or systemic bacterial or viral infections on the other hand. Noma is considered to be an opportunistic disease, but the immediate cause is uncertain. Immunosuppression associated with a high HIV load may be an important risk factor in South Africa. Cervicofacial necrotizing fasciitis, on the other hand, occurs mainly in adults. It is frequently a consequence of an odontogenic infection and is characterized by an irregular pattern of rapidly spreading necrosis of fascia, muscle, and skin. We present an unusual case of noma in a 32-year-old malnourished HIV-seropositive female with AIDS in whom, within a period of 3 days, the initial intraoral necrotizing process spread rapidly and caused circular full thickness perforating destruction of the lower lip. Prompt diagnosis and treatment brought about control of the active disease and limited the extension of the established noma and of progression of the disease at other affected oral sites.

[Dermatological conditions requiring intensive care]

Some skin conditions may require treatment in intensive care units. The early diagnosis of life-threatening dermatoses is a considerable challenge. We review skin diseases which may require intensive care. In addition to Stevens-Johnson syndrome and toxic epidermal necrolysis, representing adverse skin reactions, we discuss staphylococcal scalded skin syndrome and necrotizing fasciitis as infection-associated dermatoses, as well as angioedema. We focus on the course of disease describing clinical presentations, diagnostics and therapeutic strategies with respect to critical medical conditions.