A Dermatologist is an Internal Medicine, or for children - a Pediatric, medical doctor with additional qualifications enabling specialization in the evaluation and management of diseases and conditions of the skin, hair, mucous membranes or nails. Dermatologists may prescribe medicines as well as perform surgery for skin disorders but also have expertise in the management of cosmetic conditions of the skin such as hair loss, scars (keloids and others), and actinic keratosis or other age related skin changes. The scope of common conditions also includes acne, psoriasis, ringworm, and warts but they also manage benign and malignant skin cancers such as melanomas or moles, contact dermatitis, eczema, and allergic skin disorders. They are also frequently consulted to assess skin manifestations of systemic and infectious diseases.