Sweet or Not? Azathioprine-Induced Sweet Syndrome Mimicking Erythema Nodosum in a Patient With Inflammatory Bowel Disease

This case report highlights the clinical challenge and need to distinguish Sweet syndrome and erythema nodosum (EN) in a 50-year-old woman with newly initiated azathioprine for inflammatory bowel disease. While she initially presented with clinical features concerning for drug-induced Sweet syndrome, a subsequent histopathological examination confirmed early-stage EN. Both Sweet syndrome and EN share common triggers and therapeutic responses, but have distinctive clinical characteristics. Subtle histologic differences also exist in lesion distribution and depth of infiltration. This case underscores the need for accurate differentiation in patients with inflammatory bowel disease to initiate appropriate management and avoid potential complications.

Comparative immunohistochemical analysis of inflammatory cytokines in distinct subtypes of Sweet syndrome

Background

A dysregulated immune response has been implicated in Sweet syndrome (SS) pathogenesis; however, cytokine profiles across different conditions associated with SS - including adult-onset immunodeficiency (AOID) due to anti-interferon (IFN)-γ autoantibodies - remain unknown.

Objective

To investigate alterations in inflammatory cytokines in skin lesions of distinct subtypes of SS.

Methods

Skin biopsies were collected from 42 AOID- and 52 non-AOID-associated SS patients and 18 healthy controls. The comparative immunohistochemical study was conducted using monoclonal antibodies against interleukin (IL)-1β, IL-6, IL-17, IFN-γ, and tumor necrosis factor-α on paraffin-embedded sections. The quantitative percentage positivity and intensity were calculated using computer-based image analysis.

Results

The results showed stronger and more diffuse dermal immunoreactivity for IFN-γ and IL-17 in the AOID-associated (p < 0.001 and p < 0.001, respectively) and non-AOID-associated SS (p < 0.001 and p < 0.001, respectively) groups. However, no significant differences in the levels of these two cytokines were observed between the AOID- and non-AOID-associated SS groups. Increased expression of IFN-γ together with IL-17 was also noted in almost all subtypes among non-AOID-associated SS.

Conclusions

These results demonstrate that IFN-γ and IL-17 are implicated in immunopathology of all SS subtypes, including AOID-associated SS, despite the presence of anti-IFN-γ autoantibodies.

Pulmonary coccidioidomycosis mimicking malignancy associated with Sweet's syndrome (acute febrile neutrophilic dermatosis)

A suspicious malignant lung nodule with cutaneous reaction is not always cancer, especially in low risk for malignancy patients. A lung biopsy should be taken into consideration. The associated cause of Sweet's syndrome directs the treatment in each patient.

Sweet Syndrome: Clinical Presentation, Malignancy Association, Autoinflammatory Disorders and Treatment Response in a Cohort of 93 Patients with Long-term Follow-up

Sweet syndrome is a neutrophilic dermatosis associated with multiple disorders. This retrospective case-series study of patients with Sweet syndrome in a tertiary hospital in Spain from 2001 to 2021, explores clinicopathological characteristics of Sweet syndrome and variables associated with malignancy, presence of autoinflammatory disorders and differences between histological subtypes. A total of 93 patients were identified: 30% idiopathic, 34% malignancy-associated, 29% reactive to infections or drug-associated, and 6% with an autoimmune/inflammatory condition. Acute myeloid leukaemia was the most common malignancy (16/93) followed by myelodysplastic syndrome (7/93). Patients with acute myeloid leukaemia presented isolated flares, marked cytopaenia and rapid response to treatment, whereas myelodysplastic syndrome followed a chronic-recurrent course. The most frequent associated medications and inflammatory  disorders were filgrastim and hydroxyurea (n = 2);  and inflammatory bowel disease (n = 4). In addition, 3 patients were diagnosed with VEXAS syndrome. Male sex (p = 0.006), fever (p = 0.034), increased erythrocyte sedimentation rate (p < 0.001), anaemia (p < 0.001), and thrombocytopaenia (p < 0.001) were associated with malignancy. Histologically, patients were classified as classic (60%), histiocytoid (22.5%) or subcutaneous (15%), with pain (p = 0.011) and nodules (p < 0.001) being associated with subcutaneous-Sweet syndrome. Sweet syndrome in the context of cytopaenia should alert the presence of malignancy. An  acquired autoinflammatory condition should be explored  in relapsing Sweet syndrome with myelodysplastic syndrome. A minimum follow-up of 6 months is recommended.

A Not-So-Sweet Syndrome: A Case Report of a Male Presenting With Acute Febrile Neutrophilic Dermatosis

Physicians often encounter patients who present with a chief complaint of skin changes or lesions in both acute and primary care settings. Early initiation of appropriate treatment and pharmacotherapy in patients who present with rash is crucial to prevent decompensation, morbidity, and further downstream utilization of hospital resources. Acute febrile neutrophilic dermatosis, more commonly known as Sweet syndrome, is a rare and highly symptomatic inflammatory skin condition. Early recognition of Sweet syndrome is important as it requires specific treatment considerations and often can be a sign of an underlying pro-inflammatory condition, malignancy, or reaction to new medication that must be identified. This article discusses the presentation and management of a 50-year-old male who presented with a classic presentation of Sweet syndrome.

Cutaneous Manifestations of Rheumatoid Arthritis: Diagnosis and Treatment

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disorder characterized by inflammatory arthritis and periarticular structural damage. Available evidence suggests that RA results from complex interactions between genetic susceptibility (e.g., HLA-DRB1), environmental factors (e.g., smoking), and immune dysregulation. Alongside joint-related symptoms, individuals with RA may also experience a wide array of skin issues, including the development of nodules, neutrophilic dermatoses, vasculitis, and vasculopathy. Treatment strategies for these manifestations vary but routinely involve corticosteroids, disease-modifying anti-rheumatic drugs, and biologics, with individualized approaches guided by disease severity. In this review, we provide comprehensive insights into the skin-related issues associated with RA, outlining their clinical characteristics and histopathological findings. Our aim is to facilitate early diagnosis and personalized treatment to improve the quality of life of affected individuals.

Neuro-Sweet Syndrome: A Diagnostic Conundrum

Sweet Syndrome presents as acute fever, leucocytosis and characteristic skin plaques. It can involve many organ systems but rarely affects the nervous system. We report the case of a 51-year-old female that presented with fever, rash, headache and encephalopathy. Brain magnetic resonance imaging showed extensive T2 hyperintensities involving cerebral hemispheres, cerebellum, and brainstem. A skin biopsy revealed dermal infiltration by neutrophils consistent with Sweet Syndrome. She started steroid treatment with a good clinical response. Further questioning revealed that she had a similar episode 10 years prior that had been diagnosed as acute disseminated encephalomyelitis. Neuro-Sweet Syndrome can present with a great array of symptoms and relapses over long periods of time making the diagnosis difficult without a high degree of suspicion. Clinicians should consider this syndrome in the setting of acute encephalitis with white matter lesions that are highly responsive to steroids particularly in the presence of previous similar symptoms.

Recurrent giant cellulitis-like Sweet syndrome induced by SARS-CoV-2 Pfizer-BioNTech mRNA vaccine

Primary and booster vaccines for SARS-CoV-2 are the most effective methods of preventing infection and are generally considered safe. However, many cutaneous adverse events have been reported following vaccination. To date, there have been seven reported cases of Sweet syndrome occurring after the first dose of the SARS-CoV-2 vaccine. We describe a rare case of atypical giant-cellulitis like Sweet syndrome reemerging after receiving the SARS-CoV-2 booster vaccine.

VEXAS syndrome: A dermatological perspective

VEXAS (Vacuoles, E1 enzyme, X-linked, autoinflammatory and somatic mutation) syndrome is a genetically defined disorder identified in 2020, describing patients with inflammatory syndromes associated with haematological dysfunction. It is a severe, treatment-resistant condition, with estimated mortality between 40% and 63%. A wide range of cutaneous manifestations have been described. Here, we report on two patients with treatment-resistant neutrophilic dermatosis and myelodysplastic syndrome, who were subsequently diagnosed with VEXAS syndrome. Our cases highlight the need for dermatologists' awareness of this novel condition and to initiate early referral to haematologists for appropriate multidisciplinary care.

Clostridium difficile Infection Complicated by Transformation of Myelodysplastic Syndrome to Acute Myeloid Leukemia With Leukostasis and Sweet's Syndrome

Myelodysplastic syndrome (MDS) is a premalignant condition characterized by clonal proliferation and ineffective hematopoiesis. The subtype of MDS associated with deletion in the long arm of chromosome 5 is generally associated with older females and carries a good prognosis as it rarely transforms to acute myeloid leukemia. The mechanisms of leukemic transformation are still poorly understood and likely involve a variety of somatic mutations and epigenetic modifications. We present the case of a 70-year-old female with known MDS with deletion 5(q) who presented with anemia, thrombocytopenia, and guaiac positive stool who was subsequently found to be positive for Clostridium difficile infection. During the course of her treatment, she developed significant leukocytosis, splenic infarction, and acute hypoxic respiratory failure requiring high flow nasal cannula. Flow cytometry returned positive for increased blasts of more than 30%. She was transferred to a tertiary care facility for cytoreductive therapy and developed leukostasis and Sweet's syndrome. 

SARS-CoV-2 vaccine induced Sweet syndrome : a case report

Sweet syndrome (SS), also known as acute febrile neutrophilic dermatosis is a rare cutaneous disorder characterized by specific clinical, biological and microscopic findings. Although the exact cause of SS is still unknown, it may be triggered by infections, malignancies and drugs but also occurring after vaccinations such as bacille calmette guerin vaccination and influenza vaccine. While the recently discovered SARS COV2 vaccines are almost safe, many cutaneous and extracutaneous minor adverse effects are reported. We herein describe the fourth case of Sweet Syndrome induced by SARS-COV2 vaccine.

Subcutaneous Sweet Syndrome Presenting as Cellulitis in a Pregnant Female

We report a case of subcutaneous Sweet syndrome in a pregnant woman that was initially believed to be cellulitis. She was admitted after failure of symptom resolution following multiple oral antibiotics as an outpatient. Her rash continued to progress, and she became nauseous with a lack of appetite. Infectious disease, rheumatology, and dermatology were consulted. Skin biopsies were taken, and while awaiting results, due to continued disease progression despite broad-spectrum antibiotic coverage, IV steroids were started with rapid resolution. Eventual biopsy results showed a dense neutrophilic infiltrate in the subcutaneous fat in a lobular distribution without evidence of vasculitis, confirming a diagnosis of subcutaneous Sweet syndrome. This disease is exceedingly rare in pregnant patients, with few reported cases.

Necrotizing Cellulitis and Myositis in a Neutropenic Leukemic Patient

In this article, we review a case of necrotizing cellulitis and myositis in a neutropenic leukemic patient. He underwent a series of investigations to reach the diagnosis of pyoderma gangrenosum (PG). The lesion improved dramatically after pertinent identification and initiation of appropriate treatment. The management of PG is exceedingly challenging due to a lack of proper clinical criteria for detection and guidelines for treatment. PG must be considered as a differential in patients with enlarging, sterile, necrotic lesions, unresponsive to prolonged broad-spectrum antibiotics. Prompt recognition can prevent deeper infections and the formation of a chronic open wound causing cosmetic disfigurement along with other catastrophic complications.

Bowel-associated dermatosis-arthritis syndrome in a child with very early onset inflammatory bowel disease

A 6-year-old boy with severe very early-onset inflammatory bowel disease (VEO-IBD) was admitted for 1 week of high fevers, loose stools, joint pains, and myalgias. He subsequently developed a progressive, papular, and vesiculopustular eruption on his face with rapid spread to his trunk and extremities. Histopathology demonstrated dense dermal neutrophilic inflammation. Findings were consistent with bowel-associated dermatosis-arthritis syndrome (BADAS), which is rarely reported in children and requires further characterization.

Sweet syndrome as an adverse reaction to tyrosine kinase inhibitors: A review

Tyrosine kinase inhibitors are a class of targeted anticancer drugs that inhibit cancer cell proliferation by inactivating proteins involved in signal transduction cascades. Various cutaneous adverse events have been observed after tyrosine kinase inhibitor administration, including Sweet syndrome. We queried the PubMed database to identify 14 cases of Sweet syndrome thought to be secondary to tyrosine kinase inhibitors. Tyrosine kinase inhibitor-induced Sweet syndrome had a median of 2 months latency following drug administration. All cases but one had morphologic features classic for Sweet syndrome (erythematous and tender papules, plaques, or nodules). All cases also had classic histopathologic findings (dermal neutrophilic infiltrate without vasculitis or necrosis). Using diagnostic criteria for drug-induced Sweet syndrome and the Naranjo Drug Reaction Probability Scale for a drug-induced cutaneous eruption, we found that six cases favored a drug-induced etiology over malignancy, two cases favored a malignancy-associated Sweet syndrome, and the remaining eight met drug-induced Sweet syndrome criteria but had low Naranjo scores. Nine cases resulted in medication discontinuation, while five cases continued anticancer therapy and were treated only with corticosteroids with quick resolution of skin lesions. Dermatologists should be aware of this adverse cutaneous reaction to tyrosine kinase inhibitors and should treat on a case-by-case basis, though limited evidence in this review suggests that oncologic therapy may safely be continued with prompt corticosteroid treatment.

Bilateral sudden sensorineural hearing loss with Sweet syndrome: A case report

INTRODUCTION

Sweet syndrome (SS) is an idiopathic autoimmune disease which has been associated with various extracutaneous manifestations. Otologic symptoms secondary to SS are characterized by bilateral, progressive, sensorineural hearing loss, which requires auditory rehabilitation with, for example, cochlear implantation.

PATIENT CONCERNS

A 43-year-old woman complaining of bilateral sudden hearing loss visited the Emergency Department of our University. Abrupt onset of fever peaking up to 40°C and vomiting accompanied the hearing loss and other associated symptoms were: tinnitus that sounded like a machine humming, mild dizziness, a painful rash (on the right upper eyelid, chest, back, forearms, and lower extremities), arthralgia in both the hip and knee joints, and vision loss in the right eye. The patient had no history of autoimmune diseases or surgery.

DIAGNOSIS

Pure tone audiometry and biopsy on the skin lesion were performed. SS with bilateral sudden sensorineural hearing loss was confirmed.

INTERVENTIONS

The patient was treated with intravenous prednisolone and topical steroids.

OUTCOMES

After a week of treatment, skin lesions had improved. And 3 months after treatment, the hearing test showed full recovery.

CONCLUSION

This case emphasizes the point that early diagnosis and timely treatment are essential for hearing recovery in patients with SS who have otologic symptoms.

Panuveitis in Sweet syndrome

Ocular manifestations of Sweet syndrome, or acute febrile neutrophilic dermatosis, are usually limited to the anterior segment. We report the case of a patient with bilateral panuveitis and retinal vasculitis associated with Sweet syndrome. A 45-year-old Asian female with an undiagnosed febrile illness with rash presented with bilateral panuveitis with haemorrhagic occlusive retinal vasculitis. Skin biopsy confirmed Sweet Syndrome. Intraocular inflammation resolved with a combination of topical and systemic corticosteroids as well as intravenous cyclophosphamide, with resulting permanent severe right visual impairment. Although an uncommon condition, Sweet syndrome should be considered in any febrile patient with skin lesions and uveitis.

Secondary Syphilis with Polymorphous and Sweet Syndrome like Lesions: A Rare Case Report

Secondary syphilis can present with wide range of mucocutaneous lesions. Because of its varied morphology, it is considered a great mimicker. However, syphilitic lesions presenting as Sweet syndrome is uncommon. We report a case of a 28 year adult male presenting with erythematous edematous papules and plaques with pseudovesicular appearance, lichenoid annular plaques on skin, and painless indurated ulcer over the glans. The Venereal Disease Research Laboratory test was reactive (1:32 dilutions), and treponema pallidum hemagglutination test was positive. The histopathology from erythematous edematous lesion and genital ulcer revealed neutrophilic abscess and characteristic plasmacytic picture in biopsy, respectively. He was treated successfully with single dose intramuscular injection of benzathin penicillin 2.4 million units. This case is reported for its rarity.

Refractory Sweet Syndrome Treated with Anakinra

Sweet syndrome, otherwise known as acute febrile neutrophilic dermatosis, is an uncommon disorder characterized by the abrupt onset of painful cutaneous lesions, often with fever and leukocytosis, in patients with underlying infection, malignancy, pregnancy, or drug exposure. We present a case of a young female with long-standing Sweet syndrome refractory to standard treatments and several immunomodulators whose symptoms were ultimately controlled with anakinra.

Bullous sweet syndrome healing with prominent secondary anetoderma

A 15-month-old boy presented with 1-4 cm, pink edematous plaques with overlying round erosions and hemorrhagic bullae in the setting of a gastrointestinal illness and was ultimately diagnosed with bullous-type Sweet syndrome. Despite appropriate treatment with oral steroids, the patient's cutaneous lesions healed with secondary anetoderma. This case should prompt practitioners to be aware of bullous-type Sweet syndrome and the possibility of lesions healing with postinflammatory scarring.

Neutrophilic dermatosis of the dorsal hands: response to dapsone monotherapy

Neutrophilic dermatosis of the dorsal hands is considered a rare and localized variant of Sweet's syndrome. Although the etiology is unknown, there are reports of association with infections, neoplasias, autoimmune diseases and medications. Histopathology shows a dense neutrophilic inflammatory infiltrate in the dermis. Treatment is based on the administration of systemic corticosteroids; however, a combination of medications is useful, given the frequency of relapses. The authors report a classic and clinically exuberant case of neutrophilic dermatosis of the dorsal hands, with excellent response to oral dapsone treatment, and offer a brief literature review.

Treatment of Sweet's syndrome in pregnancy

Pregnancy-associated Sweet's syndrome is a rare occurrence (2%), with good prognosis, spontaneous resolution after delivery, and not increased infant morbidity and mortality. However, differential diagnosis is not easy for physician not familiar with skin lesions. Systemic involvement, even though unusual, might occur in nearly every organ of the body, including pericardium, myocardium, and placenta, as well as one report of early fetal miscarriage, questioning the possibility of risks underestimation. We present two further cases, one occurred in a 31-year-old woman at 26 weeks of gestation and the other on a 26-year-old woman at 24 weeks of gestation, primigravidae. Both presented with tender papules and nodules on their face and upper body parts. Laboratory examinations and skin biopsy histology were pathognomonic. Monitoring of general maternal and fetal conditions showed no signs of sufferance, but the decision to accelerate skin symptoms release, being time to delivery quite distant, challenge the treatment options. There are no recommended treatments for Sweet syndrome and the choice is very limited during pregnancy. A short course of oral steroids was very effective, with lesions healing in few days, no relapses or fetal complications. When pregnant patients exhibit fever, neutrophilia, arthralgia or myalgia, and tender erythematous plaques or nodules, Sweet syndrome should be considered. The trained dermatologist is in the leading position to address the differential diagnosis, reassure the patient, and avoid complications, even if they are rare.

Chorea revealing systemic lupus erythematosus in a 13-year old boy: A case report and short review of the literature

Among the neurological manifestations of systemic lupus erythematosus (SLE), chorea is rare, presenting in less than 7% of the pediatric SLE patients. It can appear early in the onset of SLE, be the first or even the sole clinical feature of the illness and has strongly been associated with the presence of antiphospholipid antibodies. We report on the case of a 13-year old boy, admitted with acute onset chorea and finally diagnosed with SLE. Subsequently, we present a short review of the literature on the epidemiology, suggested pathogenesis, clinical presentation and treatment of this rare presentation of SLE.

Potassium iodide in refractory, recurrent pediatric Sweet syndrome: Guidance in dosing and monitoring

We describe a 5-month-old boy with clinical and histopathologic presentation of Sweet syndrome. He responded to systemic corticosteroids, with multiple flares on tapering; potassium iodide was added, which provided complete resolution of Sweet syndrome. Potassium iodide has been used in only a few cases, and no standard dosage has been established in children. We discuss calculation of a pediatric dosage for potassium iodide in Sweet syndrome.

ERG Is a Useful Immunohistochemical Marker to Distinguish Leukemia Cutis From Nonneoplastic Leukocytic Infiltrates in the Skin

Leukemia cutis (LC) and reactive myeloid infiltrates in the skin may be difficult to distinguish pathologically, sometimes even after an extensive immunohistochemical work-up. This poses a serious clinical dilemma, as the prognosis and treatment of either condition are markedly different. Although most reactive myeloid infiltrates require a simple course of corticosteroids before the symptoms regress, the development of LC may require chemotherapeutic or transplant-variant interventions. Erythroblast transformation specific regulated gene-1 (ERG) is a member of the erythroblast transformation specific family of transcription factors, which are downstream effectors of mitogenic signaling transduction pathways. ERG is a key regulator of cell proliferation, differentiation, angiogenesis, inflammation, and apoptosis and has recently been found to be overexpressed in acute myeloid and lymphoblastic leukemia. In this study, the authors aimed to explore the diagnostic utility of ERG immunohistochemistry in LC by comparing the frequency and expression level of ERG immunostain in 32 skin biopsies, 16 with LC and 16 with reactive leukocytic infiltrates. A significantly higher frequency of ERG positivity was detected in LC (13/16, 81.4%), compared with reactive conditions (0/16). In addition, the expression level of ERG in LC, calculated using H score (mean ± standard error of mean, 188 ± 24), was significantly higher than that in nonneoplastic leukocytic infiltrate (28 ± 8). Our results strongly suggest that ERG expression is potentially an extremely useful marker to distinguish between cases of LC from those of reactive myeloid infiltrates in the skin with a positive predictive value of 100% and negative predictive value of 84.2%.

Sweet Syndrome Associated with Upper Respiratory Infection and Amoxicillin Use

Sweet syndrome (acute febrile neutrophilic dermatosis) is an uncommon dermatologic eruption characterized by acute onset of painful papules, plaques or nodules on the skin that are red, blue, or violaceous in color. It has been associated with various infections, medications, and malignancies. Here we report the case of a middle-aged male who presents with Sweet syndrome after an upper resipiratory infection and while using amoxicillin. We also review the diagnostic criteria, laboratory testing, and treatment options.

Histopathologic features in a case of hyperimmunoglobulinemia D syndrome

We describe a case of Mevalonate Kinase Deficiency (MKD) also known as Hyperimmunoglobulinemia D Syndrome (HIDS) presenting as a Sweet-like syndrome in a 5-week-old with multiple erythematous plaques, fever, aseptic meningitis, and bronchiolitis. The locations of the predominant plaques were periumbilical and periocular, which originally prompted concern for omphalitis and preseptal cellulitis. Histopathology demonstrated a neutrophilic and histiocytic dermatitis with prominent squamous syringometaplasia and leukocytoclasis in the absence of a vasculitis. This case is reported here due to the unique findings of a prominent histiocytic component in addition to the typically described neutrophilic infiltrate.