derma + logos

Greek derma meant skin, hide, or the outer covering of an animal or person — from the root dero, to flay or to strip. Derma was the word for both the tanned leather hide and the living skin of a person. Dermatology (derma + logos) as a medical specialty developed later than most internal medicine disciplines, partly because skin conditions were visible and therefore often treated by barber-surgeons, herbalists, and specialists in external remedies rather than university-trained physicians.

The first systematic dermatological texts appeared in the late 18th and early 19th centuries. Robert Willan's On Cutaneous Diseases (1808) attempted the first systematic classification of skin disorders, establishing the morphological vocabulary still used today: macule, papule, vesicle, pustule, bulla. Willan's classification gave dermatology a descriptive language.

Ferdinand von Hebra in Vienna established dermatology as a hospital specialty in the 1840s. His Viennese school — which trained physicians from across Europe and America — developed the systematic clinical examination and classification that made dermatology a recognizable medical discipline. His student Moritz Kaposi described the sarcoma that would bear his name in 1872.

Kaposi's sarcoma, originally described as a rare skin cancer, became the presenting sign of AIDS in the 1981 epidemic — purple skin lesions on young men in New York and San Francisco alerted dermatologists to the epidemic before anyone understood its cause. The skin's visibility made it a diagnostic window. Dermatology was among the first specialties to recognize AIDS.