Pigmentary disorders are frequent in children and can result in significant psychosocial problems. Hyperpigmentary disorders can be classified into melanocytes problems (epidermal, dermal) and neurocutaneous disorders presenting with pigmentation problems. Giant congenital nevus carries a low risk of malignant transformation (melanoma) but it is important to exclude cutaneous neuromelanosis in high risk patients. Malignant lentiginosis…
DetailsMelanin is produced by mature melanocytes. The biosynthesis of melanin is a complex which implicateds numerous enzymes which include tyrosinase, TRP1, TRP2…Genetic disturbances of these enzymes can result in a pigmentary dilution which translates clinically with depigmentation as is seen for example in oculocutaneous albinism. The production of melanin is done within melanocytes in organelles…
DetailsMelanin is produced by mature melanocytes. The biosynthesis of melanin is a complex which implicateds numerous enzymes which include tyrosinase, TRP1, TRP2…Genetic disturbances of these enzymes can result in a pigmentary dilution which translates clinically with depigmentation as is seen for example in oculocutaneous albinism. The production of melanin is done within melanocytes in organelles…
DetailsFrom the extremities of dendritic melanocytes, melanosomes are transfered to the neighbouring keratinocytes. However, the mechanisms implicated in this transfer are not well understood but involve an intimate contact between a melanocyte and a keratinocyte (in the epidermis). This in turn implies the presence of cell membrane proteins. The incapacity to do this explains the…
DetailsFrom the extremities of dendritic melanocytes, melanosomes are transfered to the neighbouring keratinocytes. However, the mechanisms implicated in this transfer are not well understood but involve an intimate contact between a melanocyte and a keratinocyte (in the epidermis). This in turn implies the presence of cell membrane proteins. The incapacity to do this explains the…
DetailsPigmentary disorders are frequent in children and can result in significant psychosocial problems. Hypopigmentary disorders may be caused by absence or reduction of the number of melanocytes. They can also be caused by the reduction or absence of production of melanin (with a normal number of melanocytes). Vitligo is a skin disorder which is clinically…
DetailsOral tranexamic acid taken orally is effective in the treatment of melasma (chloasma, pregnancy mask) refractory to topical combination treatment. These results are supported by evidence from previous studies frm Japan and South Korea. Tranexamic Acid (trans-4-aminomethylcyclohexanecarboxylic acid) is an anti-fibrinolytic agent which inhibits the activation of plasminogen by reversible blockade of lysine-binding molecules on…
DetailsOne of the reasons to this therapeutical frustration is due to the lack of understanding of the pathogenesis of melasma (chloasma, pregnancy mask). Although triggering factors (ultraviolet light, pregnancy, oral contraceptives) and immunohistochemical properties of melasma are well known, molecular and genetic mechanisms which are involved a poorly understood. Scientific Consensus says the following about…
DetailsMelanocytes originate from the neural crest. During early embryogenesis, melanocyte precursors migrate from the neural crest to the epidermis in a dorsolateral fashion. This migration is also done to the internal ear. This migration pathway and the maturation of the melanoblasts are regulated by a variety of factors, which included tyrosinase receptors such as c-kit.…
DetailsImproved survival with vemurafenib in melanoma with BRAF V600E mutation. Chapman PB, Hauschild A, Robert C, Haanen JB, Ascierto P, Larkin J, Dummer R, Garbe C, Testori A, Maio M, Hogg D, Lorigan P, Lebbe C, Jouary T, Schadendorf D, Ribas A, O’Day SJ, Sosman JA, Kirkwood JM, Eggermont AM, Dreno B, Nolop K, Li…
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