Wikipedia:Today's featured list/May 4, 2015
Many cutaneous conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. This broad spectrum of conditions includes diseases, such as measles (pictured), as well as many nonpathologic states, such as melanonychia and racquet nails in certain circumstances. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s). Diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data. (Full list...)