Prurigo nodularis. Histological and electron microscopical study

Acquired elastotic hemangioma‐like changes and eccrine sweat duct squamous metaplasia in lichen simplex chronicus/prurigo nodularis‐like lesions of the knee and elbow

“…8,9 In our series, new vessel formation can be seen accompanied by a mild inflammatory cell infiltrate. 10 Nerve hyperplasia has been occasionally reported, [11][12][13][14][15][16][17][18][19][20][21][22] but some authors do not consider this rare finding to be a significant criterion. 5 In AEH, the overlying epidermis is usually unremarkable or flattened.…”

Prurigo nodularis in HIV‐infected individuals

“…24 Although the socalled ''Pautrier neuroma'' has subsequently been found to represent an anomaly rather than the rule, 14 other investigators have since confirmed the presence of abnormal findings, such as neural proliferation and degeneration, in association with prurigo nodules. 14,[21][22][23]25,26 One study has demonstrated a proliferation of Merkel cells within lesions. 27 Many investigators have suggested that the neural abnormalities observed represent a non-specific reaction to injury, rather than a primary process; 22,23 however, Molina et al in 1992 reported sensory neuropeptide changes in the lesions of prurigo nodularis detected by immunohistochemistry that were not found in the lesions of lichen simplex chronicus.…”

Unusual Case of Pruritus Vulvae (Prurigo Nodularis): A Rare Case Report

“…External causes of prurigo include heat, cold, light, insect bites, ectoparasites, allergenic contactants of skin, as well as food and drug allergies. 4,5 Our patient mentioned an atopic diathesis that manifested with chronic rhinitis. Other important causes include internal infections, such as intestinal parasites, echinococcosis and internal foci of infection such as colitis or infected tonsils as super antigens from bacterial foci can cause many different skin reactions.…”

“…Thickened nerve fibers can be visualized on electron microscopy. 5 Highly characteristic for PN is the presence of thick, compact orthohyperkeratosis; irregular epidermal hyperplasia or pseudoepitheliomatous hyperplasia; focal parakeratosis or superficial epithelial necrosis; hypergranulosis; fibrosis of the papillary dermis with vertically arranged collagen fibers; increased number of fibroblasts and capillaries and a superficial, perivascular and/or interstitial inflammatory infiltrate of mainly lymphocytes and macrophages.…”