[Local dermatitis followed by pigmentation in green vervet monkeys]

A group of 154 green vervets (Cercopithecus aethiops) was studied from a clinical and pathological point of view. In 27 male and two female animals a skin lesion was noticed on genitals. Physiological blue colour of these parts due to melanin cells in deep corium turned red at first; skin was smooth without itching and acute or subacute dermatitis was present in histology. Later smooth skin got dark or blackened because of epidermal melanin pigmentation though melanocytes are lacking in normal epidermis of these vervet parts. Etiology of skin lesions was not solved but pathological changes in melanocyte localisation were stimulating for the theory of melanocyte origin.