Patients with psoriatic arthritis often report higher levels of fatigue compared with those with psoriasis alone, likely as a result of joint pain and itching, according to a recent study.
In the recent cross-sectional study, published in the Journal of the American Academy of Dermatology, investigators explored the factors contributing to fatigue in 2,741 patients with psoriasis—593 of whom had psoriatic arthritis and 2,148 of whom didn't have the disease—and 3,788 controls.
The mean age of the general population was 55.9 years (standard deviation [SD] = 16.8), 61.2 years in the patients with psoriasis (SD = 13.5), and 60.5 years in the patients with psoriatic arthritis (SD = 12.5). All groups were predominantly female (54.5% to 56.3%); and 48.6% of the controls, 27.6% of the patients with psoriasis, and 28.7% of the patients with psoriatic arthritis were never-smokers. Psoriasis onset occurred at a mean age of 30.2 years (SD = 17.7) in the patients without psoriatic arthritis and 27.2 years (SD = 15.9) in those with psoriatic arthritis. Further, psoriatic arthritis onset occurred at a mean age of 49.2 years (SD = 12.6).
The investigators utilized the Multidimensional Fatigue Inventory–20 to assess fatigue levels. They discovered that the patients with psoriatic arthritis had the highest total fatigue scores (β = 5.22, 95% confidence interval [CI] = 3.55–6.90), followed by those with psoriasis (β = 2.10, 95% CI = 0.96–3.25) compared with controls (Ptrend < .0001). Among the patients with psoriasis, increased joint pain intensity was significantly associated with higher overall fatigue (β = 2.23, 95% CI = 2.03–2.44 per 1-point increase on the numerical rating scale [NRS]).
Higher itch intensity was associated with increased fatigue scores in both the psoriasis and psoriatic arthritis groups (each 1-point increase in itch NRS score resulted in a 0.47 increase in total fatigue score [95% CI = 0.18–0.77]). Additionally, skin pain was significantly associated with overall fatigue in the psoriatic arthritis group (β = 0.65, 95% CI = 0.08–1.22) but not in the psoriasis alone group (P = .2043).
The findings demonstrated that joint pain and itch intensity, with a lesser contribution from psoriasis severity, were primary factors in fatigue among patients with psoriasis and psoriatic arthritis. A symptom-based treatment approach to manage fatigue may benefit these patients—rather than focusing solely on objective disease severity.
The study's limitations included a lack of data on the effects of pharmacotherapy (methotrexate), which could influence fatigue levels. Addressing symptoms such as joint pain and pruritus may be more effective at managing fatigue in patients with psoriasis and psoriatic arthritis.
Full disclosures can be found in the original study.