[Methotrexate to treat SAPHO syndrome with keloidal scars]

SAPHO syndrome is an uncommon clinical entity, recently described in literature, which usually affects children, young adults and middle-aged people. It is defined by the association of skin lesions (severe acne, palmo-plantar pustulosis, supurative hidradenitis), synovitis, hiperosthosis and osteitis; however, not all manifestations are required for correct diagnosis. We report a currently forty-two year-old man who initiated follow-up in 1992 for severe acne. His diagnosis changed along the years and has been treated with antibiotics many times to control pustule formation and hidrosadenitis, which evolved to keloidal scars, requiring neck zethaplasty due to limitation of mobility. In 1996 isotretinoin was started, with good response to treatment but recurrence after its completion. Ten years later, isotretinoin was being used again due to worsening clinical picture when the patient developed polyarthritis, lost 11kg in 3 months and was found to have an elevated erythrocyte sedimentation rate. SAPHO syndrome was then diagnosed by the Rheumatology clinic, which started methotrexate at 10mg per week to a good clinical response. Several cutaneous and articular flares have occurred since, however he is now clinically stable with methotrexate 20mg per week and finasteride 5mg per day. SAPHO syndrome is a rare disease and its diagnosis is often late and difficult. In this case, skin lesions preceded arthritis in several years and have been resistant to other common treatments. The patient had a better improve after initiation of methotrexate. Although the skin disease has evolved to keloids, the patient has had excellent treatment response.