Scale

A skin flake is a circumscribed collection of loosely connected horny lamellae. In a normal skin condition, skin scales occur as imperceptible (not visible) physiological exfoliation of horny cells (desquamatio insensibilis).

In a pathological skin condition, increased desquamation or pathological scaling may occur. The scales are then recognizable as visible accumulations of horny lamellae of the skin (desquamatio sensibilis).

Scaling has a high diagnostic value because it represents an underlying pathogenic process. The type of scaling allows conclusions to be drawn about the type, duration, acuity and floor of the pathogenic process.

• A distinction is made according to size:
  • Pityriasiform scaling: bran or flour-like scales
  • Small lamellar flaking: Confetti sized flakes
  • Large-lamellar scaling.
• By the type of scaling:
  • Exfoliative desquamation: flakes flaking like a film
  • Psoriatic scaling: Silvery white scales
  • Ichthyosiform scaling: callous-plate-like scales.

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2. Nast A, Griffiths CE, Hay R, Sterry W, Bolognia JL. The 2016 International League of Dermatological Societies' revised glossary for the description of cutaneous lesions. Br J Dermatol. 174:1351-1358.

3. Ochsendorf F et al (2017) Examination procedure and theory of efflorescence. Dermatologist 68: 229-242