Rare case of ankylosing spondylitis complicated by IgA vasculitis

Ankylosing spondylosis (AS) is characterised by bilateral sacroiliitis, asymmetric peripheral oligoarthritis, association with the human leucocyte antigen-B27, enthesitis and dactylitis. The association of IgA vasculitis with AS has been documented in few case reports. We present a rare case of a man in his 40s with AS, who presented with fever, bloody loose stools, abdominal pain, lower limb arthritis, palpable purpura over the lower limbs. He subsequently, also developed renal involvement in the form of proteinuria. His skin biopsy showed evidence of leucocytoclastic vasculitis, while renal biopsy showed focal proliferative, necrotising IgA glomerulonephritis. He was thus diagnosed to have Henoch Schonlein purpura with IgA nephropathy in the background of AS. He was treated with steroids and mycophenolate mofetil with resolution of his symptoms.