Psoriasis carries increased risk of serious infection
Patients with psoriasis are at risk of developing serious infection, with the severity of disease predicting greater infection risk, a study suggests.
The study used data from The Health Improvement Network (THIN) cohort and included 187,258 with mild disease, 12,442 with moderate-to-severe disease and 954,315 randomly selected controls (mean age 49.9 years; 44.3 percent male) without psoriasis. Disease severity was determined based on treatment patterns.
Patients with the skin condition (mild and moderate-to-severe disease groups: mean age 46.6 years; 48.4 percent male) were younger and more likely to be current or past smokers. Those more severe psoriasis also had higher body mass index (BMI) and were more likely to have received systemic corticosteroids.
Serious infections, such as those of the lower respiratory tract, skin and soft tissue, and upper respiratory tract, occurred more frequently in the two psoriasis vs control groups (5.4 percent vs 5.0 percent). The incidence was highest among patients with moderate-to-severe disease (7.5 percent vs 5.2 percent among those with mild disease).
Cox proportional hazards regression revealed psoriasis to be associated with an increased risk of serious infection (mild disease: hazard ratio [HR], 1.18; 95 percent CI, 1.16–1.21; moderate-to-severe disease: HR, 1.63; 1.52–1.75).
Similar results were obtained from a nested case–control analysis of 8,569 psoriasis patients in the iHOPE cohort, with disease severity classified by body surface area involvement. The HRs for serious infection were 1.21 (1.09–1.35) among psoriasis patients overall, 1.16 (0.99-1.35) in the mild disease group and 1.27 (1.10-1.47) in the moderate-to-severe disease group.
Overall, the risks of opportunistic infection and herpes zoster were significantly increased only in the moderate-to-severe disease group vs controls and were associated with immunosuppressive therapy.