Performance of drug patch tests in the diagnosis of delayed drug hypersensitivity reactions in children

Abstract

Objective To investigate the safety and clinical value of drug patch tests in diagnosing delayed drug hypersensitivity reactions (DDHR)in children. Methods Fifty-four pediatric patients with DDHR(experimental group)underwent patch tests with suspected culprit drugs, and 10 patients with mild DDHR proceeded to undergo drug provocation tests for the evaluation of the diagnostic accuracy of patch tests. Twenty healthy children(control group)underwent patch tests with common culprit drugs for the evaluation of the specificity of patch tests. Results Drug patch tests were positive in 16 out of 54 patients in the experimental group with a positive rate of 29.63%, but in none of the 20 healthy controls with a specificity of 100.00%. The positive rate of drug patch tests was 9/40 (22.50%)in patients with mild DDHR, and 7/14 in patients with severe DDHR. Patch tests were positive to 19 culprit drugs, including antibiotics, antipyretic analgesics, anti-common cold compound preparations (containing antipyretic analgesics, antihistamines, decongestants, cough-relieving and phlegm-expelling drugs, and [or]traditional Chinese medicines), as well as antiepileptics. Moreover, drug patch tests were positive in 8 (20.00%)out of 40 patients with suspected hypersensitivity to antibiotics, 4 (11.43%)out of 35 patients with suspected hypersensitivity to antipyretic analgesics and anti-common cold compound preparations, and in 4 out of 5 patients with suspected hypersensitivity to antiepileptics, but in none of 18 patients with suspected hypersensitivity to traditional Chinese medicines. Among 10 patients who underwent drug provocation tests, 7 showed consistent results between provocation tests and patch tests, 1 showed false-negative patch test reactions, and 2 showed false-negative drug provocation test reactions. Only one patient showed relapse of rashes during drug patch tests, with the incidence of adverse reactions being 1.85% (1/54). Conclusions Drug patch tests are a safe and practicable diagnostic tool for the diagnosis of DDHR in children. Trial registration Chinese Clinical Trial Registration Center, ChiCTR-DPD-14005254. Key words: Drug eruptions; Drug hypersensitivity; Patch tests; Drug provocation tests