Clinical Characteristics of Cutaneous Pain in Psoriasis.

Background: Psoriasis is a common inflammatory disease that is often associated with itch and pain. This study aimed to evaluate the clinical characteristics of skin pain among patients with psoriasis. Materials: A total of 106 patients diagnosed with psoriasis were included in the study (34% female; mean age 42.1 ± 13.0 years). Disease severity was assessed using the Psoriasis Area and Severity Index (PASI). Itch severity was evaluated using the numeric rating scale (NRS) and 4-Item Itch Score (4IIS). The intensity of skin pain was measured through the NRS, short-form McGill pain questionnaire (SF-MPQ), visual analog scale (VAS), and Douleur Neuropathique-4 questionnaire (DN4). Results: In the past week, 84.9% of psoriasis patients reported itch, while 50% of them reported skin pain. The average NRS for itch was 4.52 ± 2.88 points, and the 4IIS yielded a mean score of 6.79 ± 4.37 points. In terms of the intensity of cutaneous pain, the mean NRS was 2.42 ± 2.96 points; the SF-MPQ score averaged 4.84 ± 7.51 points; and the VAS score was 1.92 ± 2.65 points. Furthermore, 17% of adult psoriasis patients reported neuropathic pain. In 84.9% of the participants, skin pain was concurrent with areas affected by itch, while 18.9% of patients exhibited cutaneous pain encompassing all itchy areas. The pain NRS demonstrated significant correlations with the SF-MPQ (r = 0.531, p < 0.001), VAS (r = 0.779, p < 0.001), itch NRS (r = 0.551, p < 0.001), and 4IIS (r = 0.569, p < 0.001). No association was found between the pain NRS and PASI or disease duration. Conclusions: Skin pain of mild intensity and itch of moderate intensity are prevalent symptoms in psoriasis patients. Strong correlations between skin pain and itch can be explained by the process of neurogenic inflammation.