Korean J Dermatol.  2024 May;62(4):185-197.

A Review of the Classification and Diagnosis of Prurigo Nodularis in Korea

• Ahn J
• Gwag HE
• Park SY
• Son SW

Abstract

Prurigo nodularis (PN) is a disease characterized by chronic itch and presence of firm nodules or papules on the skin. The underlying pathophysiology of PN is still under debate, but it has been reported to be due to synergistic neural- and immune-mediated mechanisms. In this review, the authors summarize the etiology, epidemiology, clinical characteristics, and diagnosis of PN and suggest management protocols for patients with PN despite the absence of local guidelines for PN in Korea. The prevalence of PN in Korea was reported as 0.036%, similar to that in other countries. The various etiologies of PN are known to be associated with neural sensitization and inflammation, and the related treatment targets being studied for PN include interleukin-4, 13, 31, and transient receptor potential vanilloid 1 (TRPV1). Understanding of predisposing factors or concomitant diseases is beneficial towards targeted management of patients with PN. In addition, it has been reported that PN is more frequently accompanied by metabolic diseases, or renal disorders compared to other inflammatory skin diseases characterized by itchiness such as atopic dermatitis or psoriasis. The clinical diagnosis of PN is generally based on three core symptoms; chronic pruritus over six weeks, firm lesions, and repeated scratching. To evaluate the severity of PN, the following objective and subjective assessments can be used: Investigator’s Global Assessment for PN or Peak Pruritus Numerical Rating Scale. We propose a localized work-up algorithm for PN. It is expected that the increased awareness of PN can facilitate its diagnosis, thereby reducing the disease burden of patients with PN.

Keyword

Etiology; Prurigo; Pruritus