Sweet syndrome associated with moderate leukocyte adhesion deficiency type I: a case report and review of the literature.

Sweet syndrome is an acute febrile neutrophilic dermatosis characterized by the infiltration of neutrophils into the skin. It may occur idiopathically or be linked to malignancies, inflammatory or autoimmune diseases. Leukocyte adhesion deficiency type I (LAD-I) is an inborn error immunity wherein leukocytes lack adhesion molecules necessary for migration to infection sites due to mutations in the CD18 gene encoding ß2 integrins. We present a case of a 16-month-old female initially diagnosed and treated for Sweet syndrome based on histopathological findings with recurrent flare episodes. Subsequent workup revealed LAD-I, making this case the first documented association between Sweet syndrome and LAD-I. Moreover, we reviewed the pertinent literatures detailing the concurrence of neutrophilic dermatosis and immunodeficiency disorders. This case underscores the significance of comprehensive evaluation for Sweet syndrome patients who are refractory to conventional treatments.

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.

Sweet Syndrome as a Herpetiform Mimic: A Diagnostic Challenge.

ABSTRACT: The authors present a singular case of Sweet syndrome (acute febrile neutrophilic dermatosis) manifesting with an unusual herpetiform clinical presentation, underscoring the imperative for its inclusion in differential diagnoses of herpetic infections. A 26-year-old female patient with a systemic lupus erythematosus history presented with facial edema, hyperthermia, cephalalgia, and polyarticular pain. Dermatological examination revealed clustered, vesicle-like papules on erythematous, edematous skin, mimicking herpetic infection. Elevated acute-phase reactants and urine anomalies were noted. Histopathology confirmed Sweet syndrome, characterized by superficial and deep neutrophilic dermatitis, karyorrhexis, and papillary dermal edema. The patient responded to corticosteroid therapy and a brief antibiotic course, resolving both systemic and cutaneous symptoms. This case is remarkable for its atypical herpetiform presentation, a clinical rarity in Sweet syndrome, challenging the conventional diagnostic process. It emphasizes the necessity of considering Sweet syndrome in differential diagnoses when encountering herpetiform lesions, particularly in patients with autoimmune backgrounds. This case contributes significantly to the understanding of Sweet syndrome's clinical variability and highlights the critical role of thorough clinicopathological evaluation in achieving accurate diagnosis in complex dermatological disorders.

Sweet syndrome with peripheral neuropathy in a patient with metastatic clear cell renal cell carcinoma.

A female patient in her 70s with a newly diagnosed clear cell renal cell carcinoma (ccRCC) with osseous metastasis presented with sudden onset erythematous painful blistering skin lesions on the dorsum of both hands, with associated intermittent fever episodes. Blood tests showed elevated inflammatory marker levels (C reactive protein 257.8 mg/dL, leucocytes 17.79×109/L, with 94% neutrophils). Histologically, there was predominately neutrophil dermal infiltrate without leucocytoclastic vasculitis. The diagnostic criteria of Sweet syndrome were fulfilled. A week later, the patient developed abrupt left-hand palsy, which was confirmed as a medial and ulnar sensorimotor axonal peripheral neuropathy of paraneoplastic origin. The patient was prescribed a course of oral high-dose steroids, which significantly improved the skin lesions. The peripheral nerve palsy improved after 3 months. This case describes the two very rare concurrent paraneoplastic manifestations of ccRCC occurring simultaneously, which have been rarely reported.

Sweet syndrome induced by FLT3 inhibitors: case report and literature review.

BACKGROUND: Acute febrile neutrophilic dermatosis, also commonly referred to as Sweet syndrome, is often associated with tumors, infections, immune disorders and medications. FLT3 inhibitor-induced Sweet syndrome is a rare complication. METHODS AND RESULTS: We report a patient with relapsed and refractory acute monocytic leukemia harboring high-frequency FLT3-ITD and DNMT3a mutations. The FLT3 inhibitor gilteritinib was administered for reinduction therapy after failure of chemotherapy with a combination of venetoclax, decitabine, aclarubicin, cytarabine and granulocyte colony-stimulating factor. The leukemia patient achieved remission after 1 month of treatment. However, Sweet syndrome induced by gilteritinib, which was confirmed by skin biopsy, developed during induction therapy. Similar cases of Sweet syndrome following FLT3 inhibitor therapy for acute myeloid leukemia were reviewed. CONCLUSION: Attention should be given to this rare complication when FLT3 inhibitors are used for acute myeloid leukemia therapy, and appropriate treatments need to be administered in a timely manner.

Neutrophilic dermatosis in a patient with an IKZF1 variant and a review of monogenic autoinflammatory disorders presenting with neutrophilic dermatoses.

Monogenic diseases of immune dysregulation should be considered in the evaluation of children presenting with recurrent neutrophilic dermatoses in association with systemic signs of inflammation, autoimmune disease, hematologic abnormalities, and opportunistic or recurrent infections. We report the case of a 2-year-old boy presenting with a neutrophilic dermatosis, found to have a novel likely pathogenic germline variant of the IKAROS Family Zinc Finger 1 (IKZF1) gene; the mutation likely results in a loss of function dimerization defective protein based on reports and studies of similar variants. IKZF1 variants could potentially lead to aberrant neutrophil chemotaxis and development of neutrophilic dermatoses. Long-term surveillance is required to monitor the development of hematologic malignancy, autoimmunity, immunodeficiency, and infection in patients with pathogenic IKZF1 germline variants.

Mercaptopurine-induced Sweet's syndrome.

Sweet's syndrome is an acute febrile neutrophilic dermatosis. Drug-induced Sweet's syndrome typically occurs soon after drug administration, with rapid resolution of symptoms with cessation of the offending agent. We report a man in his early 40s who presented with fever and widespread erythematous rash on a background of recently diagnosed mild stricturing ileal Crohn's disease. He was commenced on 6-mercaptopurine 12 days before presentation. Skin biopsy demonstrated diffuse infiltration of neutrophils in the upper dermis, dermal oedema, eosinophils and fibrin deposition. Symptoms rapidly improved with cessation of 6-mercaptopurine without requiring systemic corticosteroids.

Overview of Neutrophilic Biology, Pathophysiology, and Classification of Neutrophilic Dermatoses.

Neutrophilic dermatoses are a group of inflammatory skin conditions characterized by a neutrophilic infiltrate on histopathology with no evidence of infection. These conditions present with a wide range of clinical manifestations, including pustules, bullae, abscesses, papules, nodules, plaques, and ulcers. The classification of neutrophilic dermatoses is based on the localization of neutrophils in the skin. The pathogenic mechanisms of neutrophilic dermatoses involve autoinflammation, neutrophilic dysfunction, clonal somatic mutation and differentiation of the myeloid precursors as encountered in myeloid neoplasm.

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.

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.

Pediatric Neutrophilic Dermatoses.

The term neutrophilic dermatosis encompasses a heterogeneous group of diseases, often associated with an underlying internal noninfectious disease, with an overlapping histopathologic background characterized by perivascular and diffuse neutrophilic infiltrates in one or more layers of the skin; extracutaneous neutrophilic infiltrates may be associated. Neutrophilic dermatoses are not frequent in children and, when they appear in this age group, represent a diagnostic and therapeutic challenge. Apart from the classic neutrophilic dermatoses such as pyoderma gangrenosum, Sweet syndrome, and Behçet disease, a neutrophilic dermatosis can be the presentation of rare genetic diseases of the innate immune system, such as autoinflammatory diseases.

Case Report: Type 2 Leprosy Reaction Mimicking Sweet Syndrome: A Case Report and Literature Review.

Type 2 leprosy reaction is a type of acute inflammation that predominantly affects borderline lepromatous leprosy and lepromatous leprosy patients and occurs before, during, or after therapy. The atypical variant, which resembles Sweet syndrome, could easily lead to misdiagnosis. Here, we report a case of a 52-year-old man who presented with type 2 leprosy reaction that mimicked Sweet syndrome. In addition, we review published cases and summarize their features to raise awareness of this atypical variant to enable improved diagnosis and management.

Sweet syndrome following the ChAdOx1-S vaccine.

We report a case of vaccine-induced Sweet syndrome in a female patient in her 50s presenting with fevers and a scattered red patchy rash on the lower limbs. Seven days prior, she had received the first dose of AstraZeneca ChAdOx1-S vaccine. A skin biopsy confirmed Sweet syndrome. She did not respond to high doses of prednisolone and required methotrexate therapy to induce remission. This is one of the first reports of Sweet syndrome caused by the ChAdOx1-S vaccine and provides further evidence for vaccine-induced dermatosis. This case demonstrates that methotrexate can induce remission in cases of Sweet syndrome resistant to corticosteroids. This report also describes an approach to the differential diagnosis of patients presenting with a rash, fever and malaise.

Myelodysplasia Cutis.

CONTEXT.­: Myelodysplasia cutis is an emerging concept in cutaneous neoplasia. Many of these cases were previously included under the umbrella of histiocytoid Sweet syndrome. However, with the advent of next-generation sequencing, cutaneous involvement by myelodysplastic syndrome is being increasingly recognized. OBJECTIVE.­: To review histiocytoid Sweet syndrome and myelodysplasia cutis and discuss our current understanding of these entities. Additionally, to discuss how next-generation sequencing can be applied in the evaluation of cutaneous infiltrates of immature histiocytoid cells. DATA SOURCES.­: The English-language literature from 2005 to 2023 on the topic of histiocytoid Sweet syndrome and myelodysplasia cutis was reviewed. CONCLUSIONS.­: Biopsy specimens showing infiltrates of histiocytoid, immature myeloid cells may represent cutaneous involvement by myelodysplastic syndrome. Close clinical correlation is recommended in these cases. Recent studies suggest that next-generation sequencing is useful in separating myelodysplasia cutis from true histiocytoid Sweet syndrome. This distinction has important implications for patients.

Azathioprine hypersensitivity: A Sweet-like syndrome.

INTRODUCTION: Azathioprine hypersensitivity can occasionally present as Sweet-like syndrome, a dose-independent side effect characterized by the unanticipated onset of macules, papules, and pustules. CASE PRESENTATION: A 35-year-old woman with systemic lupus erythematosus presented with complaints of generalized maculopapular rash, facial swelling, and bilateral lower extremity edema with a duration of 4 days and a 2-day history of constitutional symptoms within 2 weeks of the beginning of azathioprine therapy to treat existing lupus nephritis (class 2/3). DISCUSSION: Patients who experience azathioprine hypersensitivity syndrome can present with erythema nodosum, small-vessel vasculitis, acute generalized exanthematous pustulosis, Sweet syndrome, and nonspecific dermatosis. The following signs and symptoms are used as criteria to diagnose drug-induced Sweet syndrome: (a) abrupt onset of painful erythematous plaques, (b) histopathological evidence of dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis, (c) temperature higher than 39.7°C, (d) temporal relationship between drug ingestion and clinical presentation, and (e) temporal resolution of lesions after drug withdrawal. Our patient met three out of five criteria and was diagnosed with Sweet-like syndrome. CONCLUSION: Our case highlights the uncommonly presented azathioprine-induced Sweet-like syndrome that occurs abruptly after the commencement of the offending drug. This diagnosis can be established through basic laboratory workup and skin biopsy findings.

A diagnostic challenge-First case of chronic lymphatic leukemia-associated necrotizing sweet syndrome.

Sweet syndrome, also known as acute febrile neutrophilic dermatosis, is a rare disorder typically characterized by the clinical triad including a sudden onset of fever, painful skin lesions, and neutrophilia. The histopathological findings are a dense neutrophilic infiltrate and oedema of the dermis and epidermis without evidence of a vasculitis. Besides treatment of the underlying cause, sweet syndrome is typically treated with high-dose corticosteroids leading to a relapse-free response in 70% of patients. However, if left unrecognized or untreated, the condition may lead to serious complications. Here, we report on the case of a 38-year-old patient in whom, under the assumption of the presence of necrotizing fasciitis, exarticulation of the right arm was performed. In the absence of pathogen detection and insufficient response to anti-infective therapies, the diagnosis of a sweet syndrome was assumed and, later, confirmed by an excellent response to high-dose administration of systematic glucocorticoids. The case emphasizes the need to be aware of this rare syndrome, which can be easily misdiagnosed due to its close resemblance to infection and stresses the need of further research to define distinct diagnostic tools.