Clinical Manifestations, Treatment, and Prevention of Acute Irritant Contact Dermatitis Caused by 2,4-Dichloro-5-Methylpyrimidine Exposure in 64 Cases.

There are no reported cases of 2,4-dichloro-5-methylpyrimidine (DCP)-induced irritant contact dermatitis (ICD).The aim of the study was to summarize the clinical features, treatment, and protective measures for DCP-induced ICD.We retrospectively reviewed the clinical data from 64 patients with DCP-induced ICD and the protective measures in a DCP manufacturing factory.Disease onset occurred 1 to 10 minutes after DCP single exposure in all 64 patients. The contact site developed edematous erythematous skin lesions with clear boundaries. Other symptoms included a burning sensation (n = 48), pruritus (n = 16), headache (n = 4), nausea/vomiting (n = 3), and syncope (n = 1). Ten patients developed pruritic rash over the whole body 1 to 4 days after contacting DCP. Histopathologic examination of the lesions was performed in 8 patients; all 8 showed manifestations of ICD. A patch test with 1% DCP ethanol solution was performed in 7 patients. One patient withdrew because of pruritus and massive erythema over the whole body. Four patients had a strong reaction, and 2 patients had a very strong reaction. All patients were cured. Positive-pressure inflatable protective clothing protected workers from the outside environment to prevent DCP-induced ICD.2,4-Dichloro-5-methylpyrimidine exposure induces acute ICD and a delayed allergic reaction in some patients (15.6%). Positive-pressure inflatable protective clothing prevents DCP-induced ICD.