Subcutaneous Sweet Syndrome With Vasculitis Features: Case Report and Review.

Background: Subcutaneous Sweet Syndrome (SSS) is a rare variant of Sweet Syndrome characterized by neutrophilic infiltration of subcutaneous adipose tissue without vasculitis. The presence of vasculitis in SSS is uncommon and poses diagnostic challenges.

Case presentation: A 38-year-old female presented with a one-year history of recurrent painful erythematous nodules on her limbs and face. Physical examination revealed asymmetrical erythematous patches and tender subcutaneous nodules with central necrotic eschars on the lower limbs. Laboratory tests were unremarkable except for a mildly elevated erythrocyte sedimentation rate. Histopathological analysis showed significant neutrophilic infiltration within the adipose lobules and vascular walls, along with extravasation of red blood cells, indicating vasculitis. The patient responded promptly to systemic corticosteroids; however, symptoms recurred upon tapering, necessitating ongoing steroid therapy.

Discussion: This case underscores the rare occurrence of vasculitis in SSS, expanding the histopathological spectrum of the disease. Literature review suggests that vasculitis in SSS may result from neutrophil-mediated vascular damage rather than immune complex deposition. The recurrent symptoms upon steroid tapering highlight the therapeutic challenges in managing SSS with vasculitis.

Conclusion: Recognition of vasculitis in SSS is crucial for accurate diagnosis and effective management. Further research is warranted to elucidate the pathogenesis and develop targeted treatment strategies for SSS with vasculitis.