Sebaceous glands are involved in skin problems such as acne and keratosis pilaris. Chemical peels can be used to reduce the appearance of acne scars. Amoxicillin is occasionally used for the treatment of skin infections, such as acne vulgaris. Antibiotics applied to the skin are typically used for mild to moderately severe acne. Lepers, and others with skin diseases such as acne or psoriasis, were killed throughout Europe. The appearance of acne varies with skin color. Oral and topical probiotics are under evaluation as treatments for acne. Benzoyl peroxide is effective for reducing the number and severity of acne lesions. It is also used for the treatment of acne and rheumatoid arthritis. Topical spironolactone has been found to be effective in the treatment of acne as well. Nicotinamide cream is used as a treatment for acne. It is used as an antibiotic in the treatment of Lyme disease, acne, and bronchitis. They can be used to treat symptoms of hyperandrogenism like acne and hirsutism. Yaz is advertised as a treatment for premenstrual dysphoric disorder (PMDD) and moderate acne. Researchers are investigating complementary therapies as treatment for people with acne.