Psoriasis and Pneumonia in the End-stage Renal Disease Population

BACKGROUND: Psoriasis is a common chronic inflammatory skin disease associated with an increased risk for acute infections. Because chronic kidney disease is a risk factor for pneumonia, end-stage renal disease (ESRD) patients with psoriasis may have an increased risk for acquiring pneumonia.

METHODS: A retrospective cohort analysis was performed using the United States Renal Data System, a medical claims database of all ESRD patients undergoing dialysis in the US. Logistic regression analysis was used to investigate the association of psoriasis with pneumonia in ESRD patients.

RESULTS: A total of 6,841 (0.7%) ESRD patients were diagnosed with psoriasis; 385,976 (36%) ESRD patients had pneumonia. Although simple models showed that psoriasis was associated with an increased risk of pneumonia in the ESRD population (odds ratio (OR) = 1.14), the final multivariable model found that psoriasis was protective for pneumonia (OR = 0.56) when controlling for age, race, sex, ethnicity, dialysis modality, Charlson Comorbidity Index (CCI), multiple sclerosis, tobacco use and alcohol use. This is due to both the CCI and tobacco use being strong confounders of the association of psoriasis and pneumonia. Black, other race and Hispanic ethnicity were also protective for pneumonia, while increasing age and CCI, female sex, hemodialysis, multiple sclerosis and tobacco and alcohol use were associated with increased risk.

CONCLUSIONS: When controlling for multiple factors, psoriasis does not increase the risk for pneumonia in ESRD patients. In this cohort, other factors, such as the CCI and tobacco use, were more strongly associated with increased risk for pneumonia than psoriasis.