Thyroid dysfunction in patients with psoriasis: Higher prevalence of thyroid dysfunction in patients with generalized pustular psoriasis.

The association of psoriasis with thyroid dysfunction has been investigated; however, it remains controversial. Some papers indicate it, and others do not. Thereby, we investigated the prevalence of thyroid dysfunction in patients with psoriasis vulgaris (PsV), psoriatic arthritis (PsA) and generalized pustular psoriasis (GPP), and the relationship between the severity of psoriasis with serum free triiodothyronine (fT3), free thyroxine (fT4) and thyroid-stimulating hormone levels. Data on 85 psoriatic patients visiting our hospital from January 2015 to November 2017 (54 men and 31 women; 51 PsV, 23 PsA 23 and 11 GPP) were retrospectively analyzed. Fourteen percent of psoriatic patients had thyroid dysfunction. The percentage of patients with thyroid dysfunction was the highest in those with GPP (45% GPP, 13% PsA, 8% PsV). Patients with thyroid dysfunction demonstrated significantly higher Psoriasis Area and Severity Index scores and elevated serum C-reactive protein (CRP) levels than those without thyroid dysfunction. A significant negative correlation was observed between the serum levels of CRP and fT3 (P = 0.0032, r = -0.4635). Our data indicate that thyroid dysfunction in patients with psoriasis is associated with inflammation caused by psoriasis.