SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome defines an association of inflammatory cutaneous disorders with osteoarticular manifestations and represents a clinical and therapeutic challenge. We report a case of severe SAPHO syndrome with acne conglobata and a diffuse involvement of the anterior chest wall and sacroiliac joints that required treatment with isotretinoin and adalimumab, a new fully human anti-tumor necrosis factor (TNF)-α monoclonal antibody. Combination treatment determined a complete clinical remission of cutaneous and osteoarticular manifestations after 48 weeks. Despite maintenance of clinical remission, follow-up imaging studies after 24 months of adalimumab monotherapy revealed osteoarticular disease progression, with features of inflammatory osteitis. TNFα antagonists have been used as third-line therapy for SAPHO syndrome in single case reports or case series, but these lack consistent long-term follow-up. SAPHO syndrome can present an intermittent-favorable course in the majority of cases as well as a chronic-progressive course, the latter requiring aggressive combination treatment with TNFα antagonists and conventional systemic agents.