Psoriasis and the Risk of Pneumonia: A Population-Based Study

Abstract

BackgroundPsoriasis is a prevalent autoimmune disorder. Various studies have reported on the relationship between psoriasis and chronic diseases but very few have explored the association between psoriasis and subsequent acute infection. This retrospective cohort study aimed to compare the risk of pneumonia between subjects with and those without psoriasis.MethodsThe medical records of 14,022 patients with psoriasis and 14,022 without psoriasis were obtained from the Taiwan Longitudinal Health Insurance Database 2000. Each patient was followed-up for a three-year period. Cox proportional hazard regressions were performed to compare difference of subsequent pneumonia incidence between subjects with and those without psoriasis.ResultsThere were 206 (1.47%) subjects with psoriasis and 138 (0.98%) without psoriasis hospitalized for pneumonia. By Cox proportional hazard regressions analysis, the HR (hazard ratio) of pneumonia requiring hospitalization for patients with psoriasis was 1.50 (95% confidence interval [CI]: 1.21–1.86) compared to patients without psoriasis. The adjusted HR was 1.40 (95% CI: 1.12–1.73). The adjusted HR of pneumonia hospitalization for subjects with mild and severe psoriasis was 1.36 (95% CI: 1.09–1.70) and 1.68 (95% CI: 1.12–2.52), respectively, compared to those without psoriasis.ConclusionsPatients with psoriasis have significantly higher incidence of pneumonia compared to those without psoriasis.

Incidence of autoimmune diseases in a nationwide HIV/AIDS patient cohort in Taiwan, 2000–2012

“…New cases of autoimmune diseases were identified by selecting subjects with insurance claims data who had ICD-9-CM codes for autoimmune diseases 14 15. Autoimmune diseases in this study were categorised into two broad types: systemic and organ-specific autoimmune diseases 16.…”

Psoriasis and comorbid diseases

“…Severe psoriasis was associated with the greatest risk of hospitalized pneumonia (HR 1.68, 95% CI 1.12–2.52). 118 While neither study had access to information on potential confounders such as obesity, smoking, and drinking, subsequent cohort studies in the U.K. including this information confirmed that psoriasis is associated with increased risks of serious infection 119 including hospitalized pneumonia, 120 and further suggested that the risks may increase with greater BSA involvement by psoriasis.…”

“…115,116 The risk of serious infection among patients with psoriasis has only more recently been evaluated. 117,118 A Dutch cohort study found psoriasis to be an independent risk factor for serious infection (HR 1.54, 95% CI 1.44–1.65) whereby the greatest risk was among patients with severe psoriasis as defined by treatment patterns (HR 1.81, 95% CI 1.57–2.08). 117 Respiratory tract, abdominal, and skin infections were the most common infections among psoriasis patients.…”

Pulmonary function in patients with psoriasis: across-sectional population study

“…Smoking increases the risk of psoriasis and the disease has also been linked to chronic obstructive pulmonary disease (COPD) and asthma, with evidence of shared inflammatory cytokine‐mediated mechanisms . Moreover, patients with psoriasis display increased risk of infections, especially respiratory infections including pneumonia . However, only a small single‐centre study of pulmonary function in participants with psoriasis is available …”

“…Although the underlying mechanisms are unknown it is notable that smoking and prior pneumonia were more frequently reported in the psoriasis group and the disease has been linked to increased risk of serious infections, especially respiratory infections . It is also tempting to speculate that psoriasis‐related inflammatory airway injury and remodelling plays a role.…”