作者
Virendra Sehgal,Prashant Verma,Govind Srivastava,Ashok Aggarwal,Surabhi Verma
摘要
Melasma, a hypermelanosis of the face, is a common skin problem of middle-aged women of all racial groups, especially with dark complexion. Its precise etio-pathogenesis is evasive, genetic influences, exposure to sunlight, pregnancy, oral contraceptives, estrogen-progesterone therapies, thyroid dysfunction, cosmetics, and drugs have been proposed. Centro-facial, malar, and mandibular are well-recognized. Epidermal pigmentation appears brown/black, while dermal is blue in color, and can be distinguished by Wood's lamp illumination. The difference may be inapparent with mixed type of melasma in skin types V and VI. An increase in melanin in epidermis: basal and suprabasal layers and/or dermis is the prime defect. There is an increased expression of tyrosinase related protein-1 involved in eumelanin synthesis. The use of broad-spectrum sunscreen is important, lightening agents like retinoic acid (tretinoin), azelaic acid, and combination therapies containing hydroquinone, tretinoin, and corticosteroids, have been used in the treatment of melasma, and are thought to have increased efficacy as compared with monotherapy. Quasi-drugs, placental extracts, ellagic acid, chamomilla extract, butylresorcinol, tranexamic acid, methoxy potassium salicylate, adenosine monophosphate disodium salt, dipropyl-biphenyl-2,2'-diol, (4-hydroxyphenyl)-2-butanol, and tranexamic acid cetyl ester hydrochloride, in addition to kojic and ascorbic acid have been used. Chemical peeling is a good adjunct. Laser treatment is worthwhile.