Immunological differences between atopic dermatitis, psoriasis, and their combination in adult patients.

Abstract

The simultaneous occurrence of psoriasis (PS) dominated by Th1 lymphocytes and atopic dermatitis (AD) driven by Th2 cells is rare. This study analyzed a group of adult patients with concomitant PS and AD (ADPS) and compared the cytokine profiles of these patients with those of subjects with homogenous PS or AD and healthy controls. All patients underwent dermatological examinations, including assessment of Scoring Atopic dermatitis (SCORAD) index and Psoriasis Area Severity Index (PASI) scores, TNF-α, IFN-γ, Il-2, Il-4, Il-5, Il-6, Il-8, Il-12, I-17A, Il-18, Il-22, Il-33, and T. There were 39 patients with a diagnosis of ADPS, 45 patients with PS, 47 patients with AD, and 42 healthy controls. Patients with ADPS were mainly men with a proportional distribution of skin lesion areas. Significant differences were observed in the concentration of Il-17A between patients with ADPS and those with AD or PS and controls, which were as follows: 16.1 ± 5.4, 5.8 ± 2.1, 5.0 ± 3.1, and 3.3 ± 1.8 pg/mL, respectively. In conclusion, AD and PS might coexist as a combination disease. The role of T helper 17 cells may be more essential than previously thought.