Formaldehyde-induced urticarial vasculitis.

A 40-year-old male medical student presented with urticarial vasculitis secondary to occupational formaldehyde exposure. Serum sickness and delayed pressure urticaria also featured prominently during his illness. Initial symptom control was achieved with oral prednisolone (25 mg/day tapered to zero over 2 weeks) and oral antihistamine therapy (fexofenadine 180 mg once daily, promethazine 20 mg once daily, ranitidine 150 mg twice daily); however, subsequent exposures to formaldehyde produced transient symptom flares that broke through the prednisolone cover. A complete recovery occurred only after strict elimination of all exposure to formaldehyde, both occupationally and in the home environment, was achieved.