A Study about the Cause and Clinicopathologic Findings of Injection-Induced Dermatitis

BACKGROUND: Cases of dermatitis induced by the injection of certain drugs have been reported. OBJECTIVE: The aim of this study was to assess the cause and clinicopathologic findings of injection-induced dermatitis, and to reveal whether the reaction has any relation to the patient's age, injection site, drug concentration, and time interval from the injection to the occurrence of the skin lesion. METHODS: In this study, we enrolled 10 patients who developed erythematous skin lesions after the injection of causative drugs. The lesions were compared to each other according to the injection site, time interval from the injection to the occurrence of the skin lesion, and clinical characteristics. We performed intradermal and patch tests in each patient with different concentrations of causative drugs. RESULTS: The most common causative drugs were diclofenac and vitamin K1. The eczematous type was the most frequent clinical type. The intradermal test showed more positive results than the patch test. The patch tests with diclofenac (as is, 2.5%, 5%, and 10%) and vitamin K1 (10%) were all negative in 10 patients. Furthermore, intradermal tests with diclofenac (as is) and vitamin K1 (0.1%, 1%, and 10%) were performed in 8 patients. Six patients had a positive reaction, consisting of erythema, induration, and vesiculation, after 1 and 2 days. CONCLUSION: Our results showed that the most common causative agents were diclofenac and vitamin K1. Moreover, it seems that that intradermal test is more useful than the patch test in the diagnosis of injection-induced dermatitis.