Basic lesions

Primary lesions are skin lesions at the beginning of the dermatosis, without secondary changes. They have a greater diagnostic impact than secondary lesions.

Definition
International nomenclature for the description of cutaneous lesions. The international nomenclature includes 8 basic terms and over hundred descriptive additional terms. The unifying nomenclature serves as a crucial communication skill between dermato-venerologists and all medical disciplines which are confronted with skin problems or take care of the skin.

Skin and skin diseases present with signs and lesions that have distinct characteristics. The original lesions are defined as primary lesions, and the identification of such lesions is the most important aspect of the dermatologic physical examination. They tend to have a greater diagnostic impact compared to secondary lesions. They may be stable or be modified by progession or regression, trauma or other local or systemic factors, producing the secondary lesions. The four most important features in concisely describing dermatological findings are description of the lesions, and then their localisation, distribution and evolution.

Secondary lesions develop from primary lesions over time or by additional artifacts, like scratching. They have less diagnostic impact and often do not allow conclusions to the primary lesions, since various primary lesions may evolve to the same secondary lesion, like for example scaling.