Norwegian scabies in a patient treated with Tripterygium glycoside for rheumatoid arthritis.

We report an 80-year-old male patient with severe rheumatoid arthritis who was treated with tripterygium glycoside, an immunosuppressive agent made from the extract of a Chinese medicinal herb called Tripterygium wilfordii Hook F. The patient had no apparent skin lesions before the treatment, but he developed aggressive hyperkeratotic lesions with rapid progression after using tripterygium glycoside. He was repeatedly diagnosed with eczema, but treatment failed to achieve efficacy. Interestingly, a microscopic examination of the lesions revealed numerous scabies mites and eggs. Thus, we confirmed the diagnosis of Norwegian scabies infection. Treated with crotamiton 10% cream and 10% sulfur ointment for one month, the patient's clinical symptoms disappeared.