An illustration of a woman of color itching skin plaques caused by psoriasis.
Credit: Anastasiia Krasavina/istock

For some people, having psoriasis is merely an annoyance that causes a few flaky skin patches on occasion. For others, living with the disease means dealing with frequent flares and feeling stressed or embarrassed about how your skin looks. It also may mean dealing with issues beyond the skin. Research shows up to 30 percent of people with psoriasis will go on to develop psoriatic arthritis (PsA).

Unfortunately, if you have psoriasis, there’s no sure way to know if you will be part of that percentage that goes on to develop PsA. But a new study has identified some factors that might help patients (and their doctors) make predictions about their health so they can act early.

The study, which was published in the journal JAMA Dermatology, included 721 people who were diagnosed with psoriasis within the previous year and followed them for 10 years to learn about the course of their disease. Some of these individuals had plaque psoriasis, the most common form that causes red, scaly patches. Others had guttate psoriasis, which is characterized by the sudden onset of tiny pink bumps that cover a large area of the body and often disappears without treatment.

A small percent of people with either form of psoriasis also had PsA when the study started.

Fast-forward a decade and there were plenty of discrepancies: 20 percent of those who were initially diagnosed with plaque psoriasis and 56 percent of those initially diagnosed with guttate psoriasis had very few or non-existent symptoms, despite not receiving any treatment. Additionally, 24 percent of study participants had been diagnosed with PsA during that timeframe.

The researchers found that people who entered the study with moderate to severe plaque psoriasis, including scalp lesions, were almost five times more likely to develop severe psoriasis compared to those who had mild symptoms at the time of enrollment. Those who had enthesitis (inflammation where tendons or ligaments attach to bone) when the study began were more than four times more likely to have PsA at 10-year mark compared to those who didn’t initially report any joint pain.

Being a smoker and carrying a certain gene variant (IL12B genotype) also made it far more likely that someone would have more severe psoriasis and/or develop PsA during the study period.

While some of these factors aren’t controllable — you can’t pick whether you get guttate or plaque psoriasis, for instance — others like smoking certainly are. Perhaps most importantly, starting systemic therapy for psoriasis (an oral medication and/or drugs taken via infusion or injection to help reduce inflammation from an overactive immune system) as soon as possible could make a big difference.

“The study also found that participants who initiated systemic therapy at or before enrollment were less likely to have severe disease at the 10-year clinical examination (compared with participants who initiated systemic treatment thereafter,” the authors wrote.

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Psoriasis: Signs and Symptoms. American Academy of Dermatology Association.

Svedbom A, et al. Long-term Outcomes and Prognosis in New-Onset Psoriasis. JAMA Dermatolog.  April 14, 2021. doi:

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