Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO) Syndrome with Henoch–Schönlein Purpura: A Case Report

INTRODUCTION: SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome is a rare disease clinically characterized by a wide range of cutaneous and osteoarticular manifestations, involving multiple system impairments. Vasculitis is a rare comorbidity of SAPHO. Henoch–Schönlein purpura (HSP) is a vasculitis involving the capillaries and arterioles mediated by IgA immune complex. No case report of SAPHO syndrome with HSP was ever found. CASE: Here we reported a case of SAPHO syndrome complicated with HSP and was successfully treated by methylprednisolone and tofacitinib. DISCUSSION: Although the treat-to-target management of HSP and the first-line clinical medication have given some advices on the treatment. A precise treatment was still needed based on the pathogenesis of the comorbidity. The mechanism of the co-occurrence includes innate immunity and adapted immunity. Considering the active inflammatory reaction and the rapid disease progression, methylprednisolone and tofacitinib were prescribed. CONCLUSION: HSP is a new comorbidity of SAPHO. The spectrum of cutaneous small-vessel vasculitis in SAPHO syndrome was enriched. A new treatment approach for SAPHO with HSP was provided.