Fatigue in psoriatic arthritis: Is it related to disease activity?

Fatigue is commonly associated with psoriatic arthritis (PsA). However, information about its prevalence and associated factors is sparse. The primary objective here was to find the prevalence and magnitude of PsA fatigue. The secondary objective was to explore its associated risk factors, particularly emphasis on the effect of disease activity control.

PsA patients who fulfilled Classification Criteria For Psoriatic Arthritis were consecutively recruited from local rheumatology clinics. Fatigue was assessed by a 13-item self-administered questionnaire (Functional Assessment of Chronic Illness Therapy - Fatigue [FACIT-F]) (0-52). Data collected and analyzed included: demographic data, disease activity data, comorbidities and medications use.

There were 231 eligible PsA patients recruited. The mean FACIT-F score was 37.5 ± 9.1. Severe fatigue, defined as FACIT-F score < 30, was found in 49 (22.1%) of them. The univariate model identified these associated factors of fatigue: tender and swollen joint count, dactylitis count, Psoriasis Area and Severity Index (PASI) score, pain and general health perception, Disease Activity in Psoriatic Arthritis (DAPSA) score, Health Assessment Questionnaire, the use of cyclosporine, sulphasalazine and biologic agents. The final regression model identified DAPSA and PASI were closely associated with severe fatigue (P = .003 and P = .04 respectively). No associations with fatigue were found between age, gender, disease duration, comorbidities and medication use. However, there were weak correlations between the magnitude of FACIT-F score, DAPSA and PASI with r = -.3 and r = -.26 respectively.

Severe fatigue was common in PsA patients, and its magnitude was closely correlated with DAPSA and PASI score, indicating its multifactorial nature. Achieving DAPSA and PASI remission could significantly alleviate the fatigue intensity to a certain extent. However, treatment for PsA-related fatigue should adopt a multidisciplinary approach in addition to disease activity control.