Leflunomide in the treatment of palmoplantar pustulosis.

In 1995, a 30-year-old woman presented with a 6-day history of fever and pruritic pustules on her left hand. Physical examination revealed confluent pustules surrounded by erythema on the dorsal aspect of the left hand, palm, and wrist (Figure 1). There were no lesions in other locations. Her medical history was otherwise unremarkable. A complete laboratory blood cell count showed a slightly low white blood cell count (3600/μL [reference range, 4500-10 800/μL]; to convert to 10/L, multiply by 0.001). Findings from biochemical tests were within reference range. Cultures of the pustules were negative for organisms. Findings from skin biopsy specimens showed an intraepidermal pustule with mild acantholysis and moderate mononuclear infiltrate in dermis. A diagnosis of localized pustulosis was made. The patient was initially treated with topical and oral antibiotics with poor response. After a month, oral retinoids and topical steroids were added to her treatment, but the patient experienced new flares. Seven months after the onset of the process, she complained about arthralgias and chest and back pain. Imaging studies (radiography, computed axial tomography) revealed sacroileitis. A diagnosis of incomplete SAPHO syndrome (sacroileitis, acne, pustulosis, hyperostosis, osteitis) was made. Therapy was begun with methotrexate, 7.5 mg/wk, and the dosage was subsequently increased to 10 mg/wk. Two months later there was no improvement, so oral cyclosporine was added to her drug regimen but was poorly tolerated because of headache. During the following 4 years the patient subsequently failed treatment with sulfone, prednisone, colchicine, sulfasalazyn, and numerous nonsteroidal antiinflammatory drugs (NSAIDs).