Psoriasis induced by interferon-alpha.

Recombinant human interferon-alpha has been used in the treatment of several cancers, but there have been several reports that it may exacerbate psoriasis or trigger off its onset. We report four patients, three of whom first developed psoriasis and one who had an aggravation of the condition during treatment with interferon-alpha. Three of the patients had the carcinoid syndrome and one a renal carcinoma, and all were treated with interferon-alpha 2b or 2a (IFN-alpha 2b, 2a) with doses ranging from 1.5 x 10(6) U daily to 18 x 10(6) U three times weekly. In two of the patients there appeared to be a correlation between the severity of the psoriasis and the dosage of interferon.