Neural hyperplasia is not a diagnostic prerequisite in nodular prurigo

Reduced intraepidermal nerve fibre density in lesional and nonlesional prurigo nodularis skin as a potential sign of subclinical cutaneous neuropathy

“…With a frequency of just 2·2%, proliferation of nerve fibres in the papillary or reticular dermis was not found to be a significant criterion of PN in our study ( P = 0·731). This supports the findings of others 5,6 suggesting that dermal neural hyperplasia is not a diagnostic prerequisite in PN. Given that sensory, unmyelinated epidermal nerve fibres have been described to be of major importance in pruritus induction, 7,8 this study aimed to investigate for the first time the exact distribution of intraepidermal nerve fibres (IENFs) in PN using a sensitive technique for quantification 9,10 in a representative cohort of consecutive patients with PN.…”

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: systematic analysis of 58 histological criteria in 136 patients

“…Histological data on a total of 135 patients with PN are available in the relevant literature (Table 1). About 19 papers including case reports describe different findings, but mainly hyperkeratosis, acanthosis, papillomatosis, irregular elongation of rete ridges, or a dermal inflammatory infiltrate 9,10,13,14,16–30 . Overall, only few criteria and nondetailed descriptions were presented.…”