Sebaceous glands are involved in skin problems such as acne and keratosis pilaris. Seborrheic keratosis is the most common benign skin tumor. A skin condition that mimics goose bumps in appearance is keratosis pilaris. Several medications can cause a skin eruption similar to keratosis pilaris. Skin conditions such as keratosis pilaris, psoriasis, and eczema can also provoke the behavior. This property makes adapalene an effective treatment for keratosis pilaris and callus. The cause of keratosis pilaris is incompletely understood. Rarely seborrheic keratosis and basal cell carcinoma occur at the same location. Keratosis pilaris is the most common disorder of the hair follicle in children. There are several different types of keratosis pilaris. Doctors can generally distinguish seborrheic keratosis from melanoma upon examination, or with dermatoscopy. No particular ethnicity is at higher risk for developing keratosis pilaris. The cause of seborrheic keratosis is not known. As a cream it is used for actinic keratosis, basal cell carcinoma, and skin warts. An inadequate biopsy might be read as actinic keratosis with follicular involvement.