Weilong Zhong, Xia Wu, Wei Zhang, Jie Zhang, Xiaofan Chen, Shihong Chen, Haiyan Huang, Yong Yang, Bo Yu, Xia Dou
DOI: 10.2340/00015555-3150

Prurigo nodularis is a highly pruritic and hyperplastic chronic dermatosis with unknown pathogenesis. Many pruritogenic mediators, including nerve growth factor, interleukin (IL)-31, thymic stromal lymphopoietin, and endothelin-1, are implicated in chronic itch and inflammation. This study investigated the mRNA levels and immunoreactivity of the nerve growth factor, IL-31, thymic stromal lymphopoietin, and endothelin axes in both lesional and perilesional skin in prurigo nodularis by using quantitative real-time PCR and immunohistochemistry studies. The nerve growth factor high-affinity receptor tyrosine kinase receptor A was upregulated while the low affinity receptor p75 neurotrophin receptor was downregulated in prurigo nodularis lesions. Downregulated expression of IL-31/IL-31 receptor A and endothelin-3/endothelin receptor B and upregulation of thymic stromal lymphopoietin receptor were found in prurigo nodularis lesions. Aberrant expression of nerve growth factor, IL-31, thymic stromal lymphopoietin and endothelin axes was found in prurigo nodularis lesions, especially in the epidermis, indicating the importance of keratinocytes in prurigo nodularis pathogenesis.

· Prurigo nodularis is a highly pruritic and hyperplastic chronic dermatosis with studies mainly focusing on cutaneous nerve fibres and neuropeptides. · In this study, aberrant expression of nerve growth factor, interleukin-31, thymic stromal lymphopoietin, and endothelin axes was found in prurigo nodularis lesions, especially in the epidermis, indicating the importance of keratinocytes in prurigo nodularis pathogenesis. · The nerve growth factor high-affinity receptor tyrosine kinase receptor A was upregulated while the low affinity receptor p75 neurotrophin receptor was downregulated in prurigo nodularis lesions, suggesting the importance of receptor imbalance in prurigo nodularis pathogenesis. · These pruritogenic mediators may act as biomarkers for anti-pruritic and anti-inflammatory therapies of prurigo nodularis and need further studies.

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