What are scales (squamæ)?

Dry, laminated, epidermal exfoliations; as, for example, the scales of psoriasis, ichthyosis, and eczema.

What are crusts (crustæ)?

Dried effete masses of exudation; as, for example, the crusts of impetigo, of eczema, and of the pustular and ulcerating syphilodermata.

What are excoriations (excoriationes)?

Superficial, usually epidermal, linear or punctate loss of tissue; as, for example, ordinary scratch-marks.

What are fissures (rhagades)?

Linear cracks or wounds, involving the epidermis, or epidermis and corium; as, for example, the cracks which often occur in eczema when seated about the joints, the cracks of chapped lips and hands.

What are ulcers (ulcera)?

Rounded or irregularly-shaped and sized loss of skin and subcutaneous tissue resulting from disease; as, for example, the ulcers of syphilis and of cancer.