During a 5-year period, 61 patch-test-negative patients whose dermatitis flared after oral challenge with 2.5 mg nickel and 143 patients with positive patch tests to nickel who were not challenged orally adhered to a diet intended to reduce the daily intake of nickel for at least one month. After 1 to 2 months of dieting the dermatitis in 121 of the 204 patients had cleared or was markedly improved. One to 5 years after the initial diet treatment a questionnaire was sent to the 204 patients to inquire about the long-term results of the diet treatment. 150 patients responded to the questionnaire. 90 of these patients had continued to diet constantly or intermittently for a year or more. 88 patients felt that there was a long-term improvement as a result of diet treatment.