[Allergic contact dermatitis due to eye drops. Their clinical features and the patch test results]

We studied the clinical manifestations and causative agents in cases with allergic contact dermatitis due to eye drops who consulted the Department of Dermatology, Nippon Medical School during the period of 9 years between January, 1987 and December, 1995. Among 66,165 cases who visited the department during the studied period, 3,903 were suspected as contact dermatitis or drug eruption and underwent patch test. 141 of 3,903 cases (3.6%) were patch tested with eye drops and 49 cases (34.8%) reacted positively and were diagnosed as allergic contact dermatitis. Allergic ingredients were tested in 36 cases by the patch test with every ingredient. The 49 cases diagnosed as allergic contact dermatitis by eye drops, included 17 males and 32 females. 81.6% of the patients were aged over 40 years. The most frequent ages were between 60 and 69 years. The period from onset to the first visit to us was less than two weeks in 54.1% of the cases, but 3 cases consulted us after more than six months. The determined allergens are noted in order of frequency as follows: 1) fradiomycin sulfate in 14 cases, 2) ketotifen fumarate in 6 cases, 3) dibekacin sulfate in 3 cases, 4) befunolol hydrochloride in 3 cases, 5) phenylephrine hydrochloride in 3 cases and 6) benzalkonium chloride, the preservative of eye drops in 3 cases. Fradiomycin sulfate showed cross reactions to other aminoglycosides in the present cases. Every ingredient should be tested as much as possible, because there is a possibility that a preservative or a vehicle ingredient may be the allergen, though the incidence is low.