N-acetyl cysteine and its topical use

A method for treating cosmetic conditions and dermatological disorders selected from the group consisting of skin changes associated with intrinsic and/or extrinsic aging, ichthyosis, palmar and plantar hyperkeratoses, Darier's disease, lichen simplex chronicus, keratoses, pseudofolliculitis barbae, eczema, psoriasis, pruritus, warts, herpes, age spots, pigmented spots, blotches and mottles, nodules and mottled skin, lentigines, melasmas, blemished skin, hyperkeratoses, hyperpigmented skin, abnormal or diminished syntheses of collagen, glycosaminoglycans, proteoglycans and elastin, diminished levels collagen, glycosaminoglycans, proteoglycans and elastin, stretch marks, thinning of skin, fragile skin, deepening of skin lines and fine lines, atrophy, skin thickening due to elastosis of photoaging, loss or reduction of skin resiliency, elasticity and recoilability, elastotic changes characterized by leathery, lusterless, uneven, coarse, rough or yellowish skin, older-looking skin, telangiectatic skin and used as skin lightening and brightening,

• the method comprising applying a composition to an affected area,
• the composition comprising (A) a topically acceptable vehicle and (B) a therapeutically effective amount of N-acetyl-cysteine, and isomeric or nonisomeric, free acid, salt, lactone, amide, and ester forms thereof.