Sweet Syndrome as a Herpetiform Mimic: A Diagnostic Challenge.

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.