Myth: Psoriasis Is Infectious The precise cause of psoriasis is unknown, but researchers believe the immune system and genetics play major roles in its development, according to the National Psoriasis Foundation. The skin cells in patients with psoriasis grow at an abnormally fast rate, which causes the buildup of psoriasis lesions. Usually, something triggers psoriasis to flare.
A common misconception among patients is that psoriasis is caused by an infection. Psoriasis is not contagious and psoriasis lesions are not infectious.
However, psoriasis patients are more prone to infections than those without psoriasis. Risk factors for serious infections in psoriasis patients include immune dysregulation, systemic immunosuppressive medications, and comorbid health conditions such as diabetes mellitus or obesity. A 2016 study revealed an increased incidence of serious infections (eg, cellulitis, herpes simplex virus infection, any fungal infection, infectious arthritis, methicillin-resistant Staphylococcus aureus ) in hospitalized patients with psoriasis. Higher rates were seen among nonwhite and non-privately insured patients.
In a 2011 study, the likelihood of infectious diseases in patients with psoriasis was twice as high as the reference population. The risk was highest in patients with more severe psoriasis but was not associated with recent systemic antipsoriatic drug dispensing. Respiratory tract, abdominal, and skin infections occurred most frequently in patients with psoriasis.
Poor access to adequate dermatologic care may contribute to higher rates of infections. Dermatologists must closely monitor patients with psoriasis for infection. More research is needed to develop interventions for prevention.
Expert Commentary Psoriasis patients have long faced discrimination because of an irrational fear that their disease was somehow contagious. In fact this is completely false. This highlights the need for education of the public, so that they understand the true causes and nature of the disease.
—Jeffrey M. Weinberg, MD (New York, New York)