Narrow-band UVR affects Interleukin 17 which has a major role in the pathogenesis of psoriasis Vulgaris. the aim of this study to evaluate the serum levels of Interleukin 17 in psoriatic patients and compare with the levels in healthy controls & evaluate the effect of narrow-band ultraviolet B (NB-UVB) on the serum of Interleukin 17 and the treatment of psoriasis Vulgaris.

Nowadays Interleukin 17 has a major role in the pathogenesis of psoriasis Vulgaris.

the aim of this study to evaluate the serum levels of Interleukin 17 in psoriatic patients and compare them with the levels in healthy controls & evaluate the effect of narrow-band ultraviolet B (NB-UVB) on the serum of Interleukin 17 and the treatment of psoriasis Vulgaris. This prospective randomized clinical trial was carried out in Dermatology Department, South Valley University Hospitals included from September 2020 to August 2021, enrolled 40 psoriatic patients and 40 controls. The study was submitted for approval from the Scientific and Ethical Committees and coded as ( SVU.MED.DVA021, Code 1, N 76). Forty patients were treated with NB-UVB by starting the dose from 0.5 mJ/cm2 for all cases (Skin phototypes III or IV). The dosage is subsequently increased by 20 % per session. Sessions were given three times weekly on non-consecutive days for 12 weeks (three months). Serum Interleukin 17 levels were measured pre-and post-12 weeks narrow-band ultraviolet B by performing an enzyme-linked immune sorbent assay (ELISA). Main outcome and Measures: Improvement of psoriasis Severity Index score after 12 weeks narrow- Band UVR treatment and serum-decreased IL17 by performing an enzyme-linked immune sorbent assay (ELISA).

Inclusion Criteria:

• Patients with psoriasis diagnosed clinically

Exclusion Criteria:

• Patient with history of skin cancer. Patient with history of photosensitivity. Patient receiving immune suppressive drugs .