Merkel cell hyperplasia in circumscribed neurodermatitis: a quantitative study

Six patients with circumscribed neurodermatitis were studied to evaluate whether the epidermal hyperproliferation was associated with disturbances of the number or distribution of Merke cells (MC). The MC were identified by immunohistochemical staining, using anticytokeratins (no. 20 and 8) and anti-synaptophysin antibodies. MC were increased in number in lesional skin compared with normal skin (P < 0.0001). However, they appeared of normal morphology and were in their usual basal position. This observation supports the hypothesis that MC hyperplasia may be linked to epidermal hyperproliferation.