Emerging data have suggested a possible link between the development of plaque psoriasis and human papillomavirus (HPV) infection. “There has been research suggesting that an HPV infection predominantly stimulates systemic interleukin 17 production in HPV-induced carcinogenesis and that HPV infection provides better conditions for IL-17 secretion in the development of cervical cancer,” explains Yao-Min Hung, MD. “My colleagues and I hypothesized that HPV infection might provide better conditions for the IL-17-producing T cells and then induce the immunopathogenesis of psoriasis.” To test their hypothesis, the researchers conducted a study, published in The International Journal of Epidemiology, following patients with and without HPV diagnoses from 1997 to 2013.

Participants with HPV were matched with those without HPV (1:4 ratio by age, sex, and index year) and followed until they were diagnosed with psoriasis, they withdrew from the program, or the end of 2013 in order to compare the risk of developing psoriasis. All ambulatory medical care was tracked. To ensure accuracy, participants were only labeled “diagnosed with psoriasis” after one inpatient admission or three or more ambulatory visits with the diagnosis of psoriasis. The team used Cox proportional hazards models to estimate hazard ratios (HRs).

Participants with HPV after adjustment for demographic variables, length of hospital stay, dermatology-related outpatient visit, comorbidities, and co-medications were 1.2 times more likely to develop psoriasis than participants who did not have HPV. Patients with HPV and certain comorbidities—such as Sjogren’s syndrome, hyperlipidemia, cerebrovascular accident, chronic liver disease, urticaria, atopic dermatitis, and hepatitis C virus infection—experienced higher risks of developing psoriasis than those without these comorbidities. Although all groups experienced an increased risk of developing psoriasis with increasing age, patients aged 60 or older with HPV had the highest risk (adjusted HR, 1.649).

“Clinicians should be aware of the increased risk of psoriasis in patients with HPV and provide appropriate monitoring of the high-risk groups, in addition to treating their HPV infection,” emphasizes Dr. Hung. “New studies are required to clarify the underlying biological mechanisms of HPV and increased age; investigating the role of interleukin and nerve growth factors may prove to be helpful in this area.”