SECONDARY OR CONSECUTIVE LESIONS [Secondary or Consecutive Lesions] SCALES
(Exfoliating epidermis; Epidermal exfoliations; Squamae)
Definition. Scales are dry, epidermal exfoliations or collections of loose, dry epidermis resulting from an overproduction of epidermal cells, due to some morbid process.
The skin is constantly exfoliating an invisible amount of dead skin in the form of minute thin particles. If this is not removed by bathing, it may accumulate sufficiently to be noticeable as a branny roughness, but it is not with this form of scaling that the practitioner is concerned. Real scalines is pathologically due to an over rapidly of epidermal cell-formation or to interference with the normal process of horny transformation and is only caused by disease. There are all degrees of scaliness from the branny, flour-like, furfuraceous scales of tinea versicolor, the slightly more noticeable scales of seborrhea sicca, the moderate scaling of eczema erythematosum, and the moderate or abundant scaling of squamous eczema, ichthyosis or lichen planus to the profuse variety of psoriasis, ichthyosis and dermatitis exfoliativa. Scales may appear as thin, variously sized flakes or lamellae becoming as large as a finger-nail or even more extensive; they may be scanty and firmly attached, or abundant and freely shed; they may be dry or fatty, white, pearly white or yellowish; they may occur in single layers or massed together in variable degree. The so-called scales of seborrhea are made up of dried sebum and epithelial cells. These are sometimes known as crusty scales or scaly crusts and are of a dull or dirty color, whereas ordinary scales are gray or white, and lusterless or glistening.