Olfactory functions in patients with psoriasis vulgaris: correlations with the severity of the disease.

It is well known that psoriasis is not only limited to skin, but a systemic autoimmune disease with various comorbidities. Olfactory dysfunction, one of as a common but lesser known symptom of patients with autoimmune diseases, often presents with smell loss. The aim of this study was to assess the olfactory functions in patients with psoriasis and to compare with healthy controls. A total of 50 patients with psoriasis and 43 control subjects were included to the study. The clinical severity of psoriasis was calculated by psoriasis area and severity index (PASI). Patients were classified into two groups according to PASI score as mild (PASI ≤10) and moderate–severe (PASI >10). Olfactory function was evaluated with “Sniffin’Sticks” test. Total test scores (max. 48 points) of threshold, discrimination, and identification (TDI) were classified as normal olfaction = normosmia (>30.3 points), decreased olfaction = hyposmia (16.5–30.3 points) and loss of olfaction = anosmia ( 10) were found to be significantly lower than the patients with mild psoriasis (PASI ≤10) (p < 0.001). Olfactory dysfunction in patients with psoriasis could be thought as a comorbidity as in other inflammatory disorders. Physicians should be aware of olfactory impairment when evaluating psoriasis patients in their clinical practice.