A Patient with Pustulotic Arthro-osteitis with Isolated Spinal Lesions Successfully Treated with Risankizumab.

Pustulotic arthro-osteitis (PAO) is a rare chronic inflammatory arthropathy associated with palmoplantar pustulosis (PPP). PAO involves various extra-palmoplantar sites, including spinal lesions. Systemic treatment, including biologics, is required for refractory cases of PAO. We herein report a man diagnosed with PAO who predominantly manifested spinal symptoms. Initial treatment with non-steroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and bisphosphonates achieved a minimal response. Risankizumab, an anti-interleukin-23 p19 antibody, was subsequently administered, which resulted in significant improvement after the fourth dose, resolving both spinal and cutaneous manifestations. This case report highlights risankizumab as a potential therapeutic option for refractory PAO with spinal involvement.