Psoriasis patients at increased risk for hospitalization for infectious disease
MedWire News: Patients with psoriasis are almost twice as likely as individuals in the general population to be hospitalized for an infectious disease (ID), report Dutch researchers.
The most frequent infections seen in these patients were respiratory tract, abdominal, and skin infections, and the association was not explained by patients' recent exposure to systemic antipsoriatic drugs, as has been previously suggested, the team adds.
Tamar Nijsten (Erasmus University Medical Center, Rotterdam) and colleagues did observe, however, that: "The occurrence of IDs was substantially confounded by comorbidities such as diabetes and obstructive pulmonary diseases, partly explaining the difference between the psoriasis and reference cohort."
A group of 25,742 individuals with psoriasis and 128,710 individuals without the disease (reference subjects) were followed-up for an average of 6 years. During this time twice as many psoriasis patients were hospitalized for an ID (908 vs 438 events per 1000 person-years) as were individuals in the reference population.
In a multivariate-adjusted analysis that accounted for possible confounders including age, gender, number of previous hospitalizations, and drugs prescribed for pulmonary or diabetic diseases, the increase in risk for hospitalization among psoriasis patients after an ID remained significant, but reduced to 1.8 times that seen in the reference population.
When results were adjusted only for pulmonary or diabetic drug use, the likelihood of hospitalization of psoriasis patients after an ID decreased to 1.6 times that of the reference individuals.
Psoriasis severity also influenced the results, with a higher risk for IDs seen among patients with more severe disease. Specifically, one excess ID case occurred among every 148 patients with mild psoriasis (requiring topical therapy) compared with one in every 82 patients with severe forms of the condition (requiring systemic or PUVA therapy, or inpatient treatment).
A total of 39 of the 1793 infections in the psoriasis cohort were preceded by a recently (less than 90 days before) filled prescription for a systemic antipsoriatic drug, and 16 by inpatient psoriasis treatment. However, use these treatments did not significantly predict IDs among patients with severe psoriasis (crude hazard ratio=1.1).
Several factors may explain the higher likelihood of serious infection in patients with severe psoriasis, write Nijsten and co-workers in the Journal of the American Academy of Dermatology.
"Those with more severe psoriasis may... have a higher prevalence of comorbidities, unhealthy lifestyle factors, and/or a higher low-grade inflammatory state that can affect their ID susceptibility," they conclude.
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By Sarah Guy