Clinical response to levamisole in thirty-nine patients with erythema multiforme. An open prospective study

Patients with erythema multiforme (EM) often have chronic or recurring oral lesions that cause intense pain and interfere with a variety of functions including eating and speech. Previous studies suggest that levamisole restores to normal the function of phagocytes and T lymphocytes, and activates the inflammatory response. In our previous double-blind study 8 of 13 patients with EM had a decrease in severity and frequency of attacks. The purpose of this open prospective study was to evaluate short-term and long-term clinical efficacy of levamisole in patients with mucocutaneous EM. Thirty-nine patients with mucocutaneous EM seen in the Oral Medicine Clinic, School of Dentistry, University of California-San Francisco, comprised our study group. Levamisole was used alone in 17 patients or in combination with prednisone in 22 patients and was given as a single dose of 150 mg/day for 3 consecutive days. Thirty-one patients showed a complete response from levamisole (alone in 13 and in combination with prednisone in 18). Four showed a partial response of signs and symptoms, and four others had no benefits from levamisole whether alone or in combination. The most common side effects from levamisole were skin rash, tiredness, weakness, myalgia, taste change, and insomnia.