Double-blind study of levamisole therapy in recurrent aphthous stomatitis.

Forty-eight patients with diagnosed recurrent aphthous stomatitis participated in a randomized double-blind study of levamisole therapy. Each patient's response to treatment was determined by the following criteria: (1) days between attacks, (2) duration of lesions, (3) patient's self-evaluation of pain, (4) investigator's clinical evaluation of patient's subjective treatment response. Statistical analysis of the levamisole and placebo groups of criteria 1 and 2 above revealed no significant difference. In contrast to the above findings, analysis of the investigator's recordings of patient's subjective treatment response showed that 26% of the levamisole patients experienced marked or moderate improvement. None of the placebo patients were recorded as having experienced the same degree of benefit. Fourteen of 15 patients who complained of side effects were taking levamisole. The most common side effects were dysgeusia and hyperosmia.