Prevalence and severity of fatigue in psoriasis and psoriatic arthritis

Introduction
Fatigue is an important and underrated symptom of many chronic diseases.

Aim
The evaluation of incidence and severity of fatigue as well as the influence of selected factors on fatigue in patients with psoriasis and psoriatic arthritis (PsA).

Material and methods
The study included 60 patients with PsA, 58 patients with psoriasis and 61 persons in the control group aged 35–70 years. Assessment of fatigue was conducted using a fatigue subscale from the FACIT-F questionnaire. Severity of skin lesions and arthritis was determined with PASI and DAS28, respectively, as well as the number of painful and swollen joints, severity of pain and inflammatory markers.

Results
Severe fatigue occurred in 17%, 28%, and 1.6% of patients with psoriasis, PsA and the control group, respectively. Severity of fatigue was significantly higher in patients with PsA as compared to patients with psoriasis (p < 0.0001). In patients with psoriasis and PsA, it decreased along with the duration of psoriasis (r = 0.291, p < 0.05 vs. r = 0.382, p < 0.05, respectively). No significant correlation was found between the duration of PsA and fatigue. After using the linear regression model, severity of fatigue in psoriasis was correlated with the age of patients and the duration of psoriasis, while in PsA, with the duration of psoriasis, PASI, DAS28, CRP and the number of painful joints.

Conclusions
The results of this study may indicate the need for routine fatigue examination among people with psoriasis and psoriatic arthritis.