[Eczema caused by contact allergy to tretinoin].

Skin irritation induced by tretinoin is commonly observed, whereas allergic contact dermatitis to this drug is very rarely found in the literature. We report the case of a 34-year-old man who developed contact dermatitis in areas where a topical tretinoin preparation was applied. Patch tests were positive to tretinoin in low concentration and to isotretinoin. Oral administration of isotretinoin to this patient would carry a risk of systemic complications.