Background: Psoriasis is a common, chronic disease of the skin, in which both genetic and environmental factors play a critical role. The most characteristic lesions consist of red, scaly plaques present particularly over extensor surfaces and scalp. Studies have reported association between psoriasis and many other diseases in both cutaneous and systemic forms of the disease. Several studies with different and sometimes controversial results have been done about the relationship of hyperuricemia and psoriasis. The aim of our study was to assess serum uric acid levels in patients with psoriasis.

Methods: We studied 126 patients with psoriasis in a case-series study in Razi Hospital during one year. After recording the age, sex, duration, type and severity of the disease and presence or absence of psoriatic arthritis in the patients, they were referred to the laboratory for the determination of serum uric acid concentrations.

Results: The mean (±SD) serum uric acid level was 5.4±1.5 mg/dL (ranging from 1.9- 9.5 mg/dL). Although the mean serum uric acid levels were in the normal range but the values were significantly higher in patients with more severe forms of psoriasis (P<0.001), its longer duration (P<0.001) and psoriatic arthritis (P=0.003). Moreover, serum uric acid levels were significantly higher in patients with non-plaque-type than plaque-type psoriasis (P=0.01).

Conclusion: This study revealed that serum uric acid levels exacerbate by increases in the severity and duration of psoriasis, in psoriatic arthritis, and in patients with non-plaque-type psoriasis.