Effects of Immunomodulatory Therapy on the Skin Barrier Function in Patients with Psoriasis Vulgaris

<i>Background and Objectives</i>: Psoriasis vulgaris features epidermal barrier dysfunction. <i>Materials and Methods</i>: Barrier function changes were prospectively evaluated over 12 weeks during TNF-α inhibition with adalimumab, along with concurrent changes in disease severity and quality of life. Adults with moderate-to-severe plaque psoriasis initiating adalimumab (80 mg loading on day 1; 40 mg every other week thereafter, starting day 8) underwent assessments at baseline and at week 12 (<i>n</i> = 9; mean age 44.1 ± 14.9 years, range 20-61). Transepidermal water loss (TEWL; g/m²/h) and skin pH were measured at the elbow, lower leg, abdomen, back, and scalp; PASI, BSA, and DLQI were recorded. The measurements were standardized, though room temperature/humidity were not identical between visits. <i>Results</i>: The clinical indices improved markedly and TEWL also decreased at all sites-the elbow, lower leg, abdomen, back, and scalp-indicating barrier recovery; in contrast, the pH remained within a mildly acidic range at all sites. Lesion-to-non-lesion conversion occurred, and no site worsened. <i>Conclusions</i>: In summary, 12 weeks of adalimumab were associated with a notable clinical improvement and consistent, site-spanning reductions in TEWL, whereas skin surface pH showed no material change. TEWL appears to be a sensitive objective adjunct to clinical indices for monitoring response.