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.