6.3.3 Melasma/Chloasma/PIH

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Frequent disorders. PIH develops following physical or chemical trauma, inflammation or drug induced changes that increase melanocyte activity and/or result in basal membrane destruction with melanocyte death and melanophage accumulation in the dermis. Chloasma is most frequent in women during and after pregnancy or under hormonal contraception, especially in dark skinned people (South America, Southeast Asia, mediterranean region).

Melasma is a troublesome hyperpigmentation of the face. PIH can occur at any body site of the skin as a consequence of preceding skin irritation, damage or inflammation. Both diseases are more frequent in people with darker skin phototypes.

Physical (UV-light), chemical (cosmetics), drugs (minocycline), hormones (women, pregnancy, contraceptives) and genetic disposition (coloured skin/phototypes III - VI) play an important role. PIH can develop following from acne lesions, cutaneous lupus erythematodes, lichen planus or other skin diseases, or after traumatic events, such as, friction.

Usually not needed. In order to determine the localisation of pigment a biopsy may sometimes be recommended. Increased deposits of melanin in basal keratinocytes and in melanophages of the dermis. Wood´s light can be used to better localize the deposited pigment in melasma. Dermoscopy can be useful too.

Can be aesthetically compromising; decreased quality of life index and psychosocial impact possible.

Phototoxic dermatitis; (exogenous) ochronosis. Drug-induced hyperpigmentation of the skin, for example, by minocycline.

Strict UV-protection against UVA/B and high-energetic visible light (blue light) in persons with darker skin phototypes (III-IV) is required for both patients with melasma and PIH. Topical bleaching with a combination of hydroquinone, tretinoin (a retinoic acid derivative) and hydrocortisone (so-called Kligman’s formula) has been used for decades but hydroquinone is currently banned due to safety concerns. Low dose-oral tranexamic acid has been shown to improve melasma. Oral melatonin has weak skin-lightening effects. Some cosmeceuticals (for example thiamiadole) have proven efficancy against facial hyperpigmentation and melasma. Azelaic acid, retinoid acids and superficial chemical peeling can be useful. Laser treatment is a second-line option due to high recurrency rates.