Positive patch test reactions to Phenergan (promethazine-) cream are frequently observed. In most cases these reactions are considered to be due to a non-allergic irritative effect of the ointment base. Only In a minority of the cases a true hypersensitivlty to promethazine is found. Four out of 8 patients who showed positive patch test reactions to promethazine also presented positive allergic reactions to tri-ethanolamine, which Is one of the ingredients of the ointment base of the Phenergan cream. These reactions may be due to a cross-sensitization since both tri-ethanolamine and promethazine are tertiary amines.