Cutaneous reactions to drugs. An analysis of spontaneous reports in four Italian regions.

Cutaneous manifestations are frequently reported in association with drug use. The aim of the present study was to estimate the reporting rate of cutaneous drug reactions and to determine the main characteristics of the reactions reported in the context of a spontaneous surveillance system. All of the adverse drug reactions (ADRs) reported spontaneously between January 1996 and December 1997 to the surveillance systems of four Italian Regions (a total population of about 20 million people) were analysed by a panel of experts including dermatologists. On the basis of the Critical Term List of the World Health Organization (WHO), the reactions were classified as either serious or non-serious events. Drug consumption was expressed as a daily defined dose (DDD)/1000 inhabitants/day. A total of 2204 adverse skin reactions (44.3% of all of the reported ADRs) were identified, making a reporting rate of about 5.5 per 100,000 inhabitants/year. The female/male ratio was 1.58, and the reporting rate progressively increased with age. The drug categories with the highest number of cutaneous reactions were antimicrobials, followed by nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics and radiology contrast media. There was a total of 372 (16.9%) serious reactions, the most frequent being angioedema (171 cases), erythema multiforme (68 cases) and photosensitivity (37 cases). Co-trimoxazole, followed by the cephalosporins and fluoroquinolones, were associated with the highest consumption-adjusted reporting rate among the antimicrobials, and aspirin and dipyrone among the NSAIDs and analgesics. In our surveillance system, the skin was the organ most frequently affected by ADRs. Assessment by an expert panel including dermatologists is recommended.