Psoriasis is associated with increased risk for serious infection, according to the results of cohort study data published in the British Journal of Dermatology. During 5 years of follow-up, patients with psoriasis were more often hospitalized for infections than individuals without psoriasis.
Investigators conducted a cohort study of adults (≥18 years) with and without psoriasis using the United Kingdom Clinical Practice Research Datalink (CPRD). CPRD data were linked to hospital and mortality records in the United Kingdom for the years 2003 to 2016. Patients with psoriasis were matched with up to 6 control patients by age, sex, and place of clinical care. History of hospitalization was ascertained from the Hospital Episode Statistics database; death was ascertained from Office of National Statistics mortality records. Stratified Cox proportional hazard models were used to examine the relationship between psoriasis, hospitalization, and mortality. Models were adjusted for age, economic deprivation, body mass index, alcohol intake, smoking status, and comorbid conditions.
The study cohort comprised 69,312 patients with psoriasis and 338,598 comparators. Patients and comparators were followed for a median (interquartile range) of 4.9 (5.9) and 5.1 (6.3) years, respectively. The incidence rate of serious infection was 20.5 per 1000 person-years (95% confidence interval [CI], 20.0-21.0) in patients with psoriasis and 16.1 per 1000 person-years (95% CI, 15.9-16.3) in comparators. The fully adjusted hazard ratio (HR) for hospitalizations due to infection was 1.36 (95% CI, 1.31-1.40) in patients with psoriasis vs comparators. When analyses were stratified by infection type, patients with psoriasis had the highest HR for skin and soft-tissue infections (HR, 1.56; 95% CI, 1.43-1.70). Risk for respiratory infections was also increased (HR, 1.35; 95% CI, 1.27-1.44). Death due to any infection was also more common in patients vs control patients (HR, 1.33; 95% CI, 1.08-1.63).
Although the absolute risk for serious infection in patients with psoriasis was small, the likelihood of hospitalization and death were nonetheless increased compared with control patients. Future research is necessary to explore the mechanism by which psoriasis increases risk for certain infections, particularly soft-tissue and respiratory infections. As study limitations, investigators noted the risk for residual confounding and detection bias implicit in using hospital records. Increased psoriasis severity did not appear to influence risk for infection, suggesting that disease severity may have not been properly captured. Despite those findings, these results provide evidence for an increased risk for serious infection and hospitalization in patients with psoriasis.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry.
Please see the original reference for a full list of authors’ disclosures.
Yiu ZZN, Parisi R, Lunt M, et al . Risk of hospitalisation and death due to infection in people with psoriasis: a population-based cohort study using the Clinical Practice Research Datalink [published online March 28, 2020]. Br J Dermatol. doi: 10.1111/bjd.19052