Cutaneous Nerve Lesions in Prurigo Nodularis. Electron Microscopic Study of Two Patients

Abstract

Skin biopsies from 2 patients with prurigo nodularis were studied by EM. Lesions were found in the cutaneous myelinated and unmyelinated nerves. Schwann-cell cytoplasm showed large, irregular, membrane-bound, electron-lucent vacuoles. Unmyelinated axons were distended and devoid of neurotubules and neurofilaments. Myelinated nerves showed various degrees of demyelination. Onion-bulb formations with a centrally located myelinated fiber were also observed and numerous mast cells were found in the cellular infiltrate. This indicated the presence of a chronic peripheral neuropathy, whose etiology remains to be determined.