Pigmentation disorders

Pigmentation disorders are diseases associated with an excess or lack of melanin, or the presence of another endogenous or exogenous pigment.

Hyperpigmentation
Hyperpigmentation is an excess of melanin.
 * Ephelides, freckles – are sharply demarcated, yellowish or brown spots several mm in size. Rarely, they can also appear on the lips and oral cavity. It belongs to dominantly inherited deviations
 * Peutz-Jeghers syndrome – is an AD hereditary disease. It is manifested by intestinal polyposis and freckle-like pigmentation around the mouth and on the red lip.
 * Chloasma uterinum (melasma) are large, sharply defined, yellowish to yellowish-brown spots. They appear symmetrically on the temples and faces of girls and women. occurrence is determined by hormones, they often appear during pregnancy.
 * Poikilodermia Civatte is hyperpigmentation associated with telangiectasias. It occurs in middle-aged women on the lateral surfaces of the neck, probably after photodynamically acting substances.

Secondary hyperpigmentation

 * after illnesses, mechanical, physical, chemical dermatitis, photodermatoses, psoriasis, lichen ruber, chronic eczema, atopic dermatitis, ...

Removal - various bleaching agents (unreliable) - hydrargium amidochloratum, hydrogen peroxide, ...

Hypopigmentation
Hypopigmentation is a lack of melanin.
 * Leucoderma is secondary depigmentation at the site of healed skin disease manifestations. It usually retains the shape of the original efflorescences;
 * lleukoderma psoriaticum, syphiliticum, …
 * Albinism is an AR hereditary disorder of the tyrosinase enzyme metabolism associated with a total or partial absence of melanin.


 * Vitiligo s a progressive chronic disease of unknown cause. It affects more women. Occurrence is often familial. It manifests itself as sharply defined white spots of various sizes, the edges of which have a "fan-like" hyperpigmentation. Hair may be bleached.

Dyschromia
Dyschromia is hyperpigmentation caused by pigments other than melanin.
 * Hemosiderin pigmentation - hemosiderosis (capillaritis) is most often on the lower legs in varicose veins. It is a disease of unknown etiology manifested by itching, eczema and petechiae.
 * Bile dyes - manifested as jaundice.


 * Exogenously - argyrosis is a gray discoloration of mucous membranes after treatment with silver solutions. It first appears on the gingiva. Exogenous dyschromia also includes tattoos.

Related articles

 * Pigment
 * Phototypes
 * Jaundice
 * Anatomy of the skin
 * Physiology of the skin