How are lesions of the skin classified?

Lesions of the skin are classified primarily into two categories: primary and secondary lesions. Primary lesions are directly related to a pathological process and manifest as the first signs of a skin disorder. Examples of primary lesions include macules, papules, nodules, cysts, and blisters. Secondary lesions, on the other hand, arise from primary lesions or result from changes to the skin as they evolve. They include scales, crusts, scars, and ulcers, which can present as complications or subsequent forms of the initial lesion.

The classification into primary and secondary provides a framework for understanding the nature and progression of skin conditions, making it essential for diagnosis and treatment in esthetics. The reference to tertiary or quaternary lesions is less standard and typically not utilized in the classification of skin lesions. Therefore, primary and secondary are the appropriate classifications that form the basis of dermatological practice.