See also the separate Dermatological History and Examination article. Show
Dermatological terminologyDermatologists can sound erudite when they use the abundance of descriptive terms at their disposal. These terms are often simply describing the rash in Latin. Sometimes the words are of Greek derivation such as ichthyosis (meaning scales like a fish). Latin or Greek dermatological terminology may be used but the two should not be mixed. The skin is affected by a vast number of insults and diseases, including genetic and metabolic abnormalities as well as infections, and yet there is a limited number of ways in which it can respond. History and examination involve making an assessment of the condition, including describing it. Simply understanding dermatological terminology will facilitate diagnosis. Basic dermatological terminology
Structure of skinThe skin has three layers called epidermis, dermis and deep subcutaneous tissue with a basement membrane between the epidermis and the dermis. EpidermisThe epidermis has an outer layer of cells called keratinocytes, which produce keratin. The epidermis also contains pigment cells called melanocytes, which produce melanin, Langerhans' cells, which are part of the immune system, and Merkel's cells, which have a sensory function.
Epidermal appendages
DermisThe dermis is composed of connective tissue that supports the epidermis, providing nutrients and protection. The papillary dermis is the upper portion beneath the epidermis and the lower portion is the reticular dermis.
Subcutaneous tissueThis is also called subcutis and is composed of adipose cells or lipocytes. These are surrounded by connective tissue, blood vessels and nerves. Dermatological terms for distribution of lesionsThis is important, as the distribution of lesions is often characteristic and hence of diagnostic importance:
Dermatological terms for the shape of a lesion
Colour
Discrete lesions
Epidermal changesScaling or hyperkeratosis is an increase in the dead cells on the surface of the skin called the stratum corneum. Descriptive terms for scale include:
Secondary changes
Nails
Mucocutaneous membranesIt is important in dermatology to examine the mucocutaneous areas of the body, particularly the mouth and lips. Most oral involvement in the mucocutaneous diseases is associated with an immunological component to the disease. When an eruption is on a mucous membrane, it is called an enanthem. Examples include:
Miscellaneous dermatological terms
What is defined as lesions that involve loss of skin surface?EROSION - A shallow, moist, or crusted lesion resulting from the loss of the superficial layers of the upper epidermis only, as from friction or pressure. Example: Ruptured varicella vesicles. EXCORIATION - A skin abrasion that is usually superficial and due to scratching of the skin.
What are the 3 types of skin lesions?Lesion Type (Primary Morphology). Macules are flat, nonpalpable lesions usually < 10 mm in diameter. ... . Papules are elevated lesions usually < 10 mm in diameter that can be felt or palpated. ... . Plaques are palpable lesions > 10 mm in diameter that are elevated or depressed compared to the skin surface.. What is papule and macule?Macule — a small patch of skin that is altered in colour, but is not elevated. Patch — a large area of colour change, with a smooth surface. Papule — elevated, solid, palpable lesion that is ≤ 1 cm in diameter. They may be solitary or multiple.
What is a papule skin lesion?Papule: a circumscribed, elevated solid lesion up to 1 cm in size, elevation may be accentuated with oblique lighting, e.g. Mila, acne, verrucae. Plaque: a circumscribed, elevated, plateaulike, solid lesion greater than 1 cm in size (e.g. psoriasis).
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