Cutaneous reactions induced by calcium channel blocker: high frequency of psoriasiform eruptions.

Fifteen cases with cutaneous reactions to calcium channel blockers (Ca-antagonist), dihydropiridine (including nicardipine, nifedipine, nisoldipine), verapamil, and diltiazem are reported. The patients from Yokohama City University Hospital and affiliated hospitals included 4 males and 11 females with cardiovascular diseases. Their average age was 64.7 (54 to 82) years. They had been taking Ca-antagonists for an average of 95 days (7 days to 10 years) before they developed dermatitis. The frequency of reactions to Ca-antagonists was high with diltiazem (5/16:31.25%) and dihydropyridine (7/16:43.75%), including nifedipine (4/7), nisoldipine (1/7), and nicardipine (2/7). Stevens-Johnson syndrome (MCOS) was associated only with verapamil. A notable type of eruption was the psoriasiform type, including exacerbation of psoriasis, which was resolved or easily controlled after discontinuation of the drug. Provocation tests verified the Ca-antagonist as the cause in 7 cases of psoriasiform eruption. The frequency of positive patch tests to Ca-antagonists was low except for diltiazem. Patch tests with diltiazem showed positive reactions in 54% (7 of 13 patients), based on our experience and papers published in Japan. Ca-antagonists are occasional causes of a wide spectrum of cutaneous reactions and should also be considered as causative factors in patients who develop psoriasiform eruptions or in patients whose psoriasis is exacerbated while using these drugs.