RESUMO
BACKGROUND: The frequency of allergy to drugs is 5-10% in the general population, The Shelley's test is a method in vitro for its diagnosis and it is considered positive when it is equal o greater than 20%. OBJECTIVE: To show the allergy to drugs frequency evaluated by the Shelley's Modified Test. MATERIAL AND METHODS: We included 165 patients with clinical diagnosis of allergy to drugs to those who the test of Shelley's was applied modified test for one or several medicines. The study was made in the period of January 1st to December 3st 2002. RESULTS: 88% (145 patients) were positive, and 12% (20 patients) were negative in correlation with clinical findings. The female was more determinant (2:1 relation), with an average age of 45 years. The drugs that caused reactions of allergy in were the antibiotics (sulfas, penicillin, quinolones), analgesic (ASA, naproxen, diclofenac), antihypertensive (enalapril, captopril, verapamil) and others with 95, 170, 48 and 97 cases respectively. The most frequent clinical features were urticaria, angioedema, anaphylactic shock and erythema. CONCLUSION: The Shelley's test is useful to support the diagnosis of allergy to drugs, although does not exclude it. The antibiotics intake is the most common cause and the most common clinical manifestation was urticaria.