Ulcerative contact dermatitis caused by sodium silicate. Coexistence of primary irritant contact dermatitis and contact urticaria.

A 57-year-old man had had recurrent ulcerative lesions on his left hand for two years. The ulcers were associated with chronic eczematous changes resulting from primary irritant contact dermatitis to sodium silicate, as indicated by positive patch tests. The patient also had another type of cutaneous reaction to sodium silicate, ie, contact urticaria. An immediate wheal and flare reaction was found 15 minutes after application of sodium silicate to a scratch test site. This response was not seen in healthy control subjects. To our knowledge, the coexistence of primary irritant contact dermatitis and contact urticaria, both induced by sodium silicate, has not previously been described.