225 Possible mechanism underlying hypopigmentation in psoriatic lesion

Vitiligo is sometimes complicated with psoriasis, and more frequently, pigmentation or depigmentation arises after psoriatic lesion subsides. It not clear whether melanocyte function maintained in which characterized by keratinocyte proliferation, how melanin migration to keratinocytes affected, we will discuss the behavior of pigment cells psoriasis lesions. Melanin-containing were observed mainly basal layer uninvolved lesions normal control skin, but few melanin-containing found The number melanocytes was about twice as high those examination electron microscopy showed that many melanosomes lesions, tended decrease on one thin slice section. Moreover, stages II III non-lesional significantly different, stage IV be reduced. Therefore, it likely hypopigmentation may due “dilution effect” transferred surrounding keratinocytes, undergo hyper-proliferative state. reduced, suggesting overgrowth epidermis have resulted immature inefficient transfer from keratinocytes.