What are the side effects of topical tretinoin?

The most common side effect is an irritant reaction that manifests as erythema and scaling. Severe irritant reactions may require decreasing the concentration or frequency of application. True allergic contact dermatitis to topical tretinoin preparations has been reported but is rare. An unusual potential problem is that the topical tretinoin gels are flammable. At least one dermatologist has reported that it is useful during hunting trips for starting campfires! Patients who are not able to tolerate tretinoin gel or cream may be able to tolerate tretinoin gel with microspheres and adapalene gel, because they are less irritating.