Flat warts can be treated with retinoic acid cream. The main ingredient of retinoic acid cream is all-trans retinoic acid, which can induce epidermal hyperplasia and thicken the granular and echinocyte layers, and can also prevent and eliminate acne lesions. It is suitable for adjuvant treatment of flat warts, common acne, hairy red furfurace, follicular keratosis, mucous membrane leukoplakia and psoriasis, so flat warts can be treated with retinoic acid cream. The drug is contraindicated in eczema, acute and subacute dermatitis, skin folds broken, pregnant women are prohibited. Avoid sunlight during the use of the drug, after the use of the drug may appear burning sensation, erythema and flaking and other skin irritation symptoms that aggravate the original symptoms, on behalf of the drug is playing a role. As the skin gradually adapts to and tolerates the effects of the drug, such irritation may gradually disappear. On the contrary, if the irritation persists or worsens, consult your physician to choose to intermittently or suspend the use of the drug. The use of specific medications should be directed by a specialist.