Disorders of Pigmentation

Abstract

Skin color is highly individual and the variations are controlled by numerous genes. The different skin colors result from the size and number of melanosomes and do not mirror the amount of melanocytes. Disorders of pigmentation can result from migration abnormalities of melanocytes from the neural crest to the skin during embryogenesis. In addition, impairment of melanosome transfer to the surrounding keratinocytes, an alteration in melanin synthesis and a defective degradation or removal of melanin may lead to abnormal skin pigmentation. Immunologic or toxic mediated destructions of melanocytes can end in pigmentation disorders. Disorders of pigmentation are classified in hypo- or hyperpigmentation which can occur as a genetic or acquired disease. They can manifest locally or diffuse. Congenital hypopigmentation can be restricted to the skin as in piebaldism or they represent a systemic disease as in Menkes disease or phenylketonuria. Localized hypo- or hyperpigmentation in children may serve as markers for systemic diseases. Ash-leaf hypopigmentation are characteristic for tuberous sclerosis and more than 5 café-au-lait spots suggest neurofibromatosis 1 (von Recklinghausen disease). The most common autoimmune-induced depigmentation is vitiligo. Generalized hyperpigmentation only rarely reflects a primary genetic disorder but is most often from acquired diseases as in Addison disease, secondary hemochromatosis or primary biliary cirrhosis. Treatment of pigmentation disorders are based on a diagnosis which sometimes allow a specific intervention. Cosmetically acceptable results are difficult to obtain.

Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma

“…Vitiligo affects 1-2% of the world population and it is characterized by the destruction of melanocytes, promoting smooth formation of white patches in the midst of the normally pigmented skin which usually initiates on the hands and feet and then spreads to several parts of the body (Abu Tahir et al, 2010;Fistarol and Itin, 2010). Besides skin manifestation, vitiligo promotes profound effect on people quality of life (Radtke et al, 2010;Talsania et al, 2010).…”

“…The most common hypopigmentant skin disorder is vitiligo, which is an autoimmune-induced depigmentation disease (Fistarol and Itin, 2010). Vitiligo affects 1-2% of the world population and it is characterized by the destruction of melanocytes, promoting smooth formation of white patches in the midst of the normally pigmented skin which usually initiates on the hands and feet and then spreads to several parts of the body (Abu Tahir et al, 2010;Fistarol and Itin, 2010).…”

Pigment Genodermatoses Affecting Melanocyte Development and Migration from the Neural Crest: Piebaldism, Waardenburg Syndrome and Cross- McKusick-Breen Syndrome

“…Disorders of pigmentation are classified in hypo-or hyperpigmentation which can occur as a genetic or acquired disease. They can manifest locally or diffusely [4,5].…”

Genetisch bedingte Pigmentstörungen

“…Darüber hinaus findet man selten eine Beteiligung des Immunsystems oder anderer extrakutaner Organe. Abgegrenzt werden müssen sekundäre Pigmentstörungen, die bei zahlreichen genetischen Erkrankungen mit Defekten außerhalb des Pigmentsystems beispielsweise in Form einer Poikilodermie einhergehen, als auch erworbene Pigmentstörungen [22]. Da gerade die beiden letztgenannten Gruppen sehr vielfältig sind, liegt der Fokus der folgenden Übersicht auf primären genetischen Pigmentstörungen.…”