Psoriasis severity may be linked to an increased risk of death

Patients with psoriasis covering 10% or more of their bodies are at almost double the risk of death, according to a study published in the Journal of Investigative Dermatology. It is the first study to link the severity of psoriasis to an increased risk of death using body surface area (BSA), an objective measure of disease severity, rather than according to treatment modalities (oral, injectable, or phototherapy).

“It’s well established that psoriasis is associated with an increased risk for other comorbidities like chronic kidney disease, diabetes, and cardiovascular disease, but we don’t yet understand how the severity of psoriasis impacts future risk of major health problems,” said senior author Joel M. Gelfand, MD, MSCE, professor of dermatology and epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.

Dr. Gelfand and colleagues used a database from the United Kingdom to identify 8,760 patients with psoriasis and 87,600 individuals without it. Patients’ general practitioners were sent a survey to determine the body surface area affected by psoriasis, and researchers used BSA, a measurement of the percentage of the body covered by psoriasis. The number of deaths in each group by person-years was determined.

After an average follow-up of 4 years, an average of 6.39 deaths per 1,000 person years occurred in those patients with psoriasis covering over 10% of their bodies. This was compared with 3.24 deaths per 1,000 person years in those without psoriasis.

Even after adjusting for other demographic factors, Dr. Gelfand and fellow researchers found that patients with a BSA greater than 10% were 1.79 times more likely to have died, a risk that was almost double that in age- and gender-matched controls without psoriasis. The risk persisted even after controlling for other risk factors such as smoking, obesity, and major medical conditions.

“Other studies that have examined this question, including our own prior research, have looked at patients who were receiving treatment for psoriasis, which is not an objective measurement of severity, making it unclear to whom the prior studies apply,” said lead author Megan H. Noe, MD, MPH, dermatologist and post-doctoral research fellow in Dr. Gelfand’s laboratory. “By using BSA, which we can evaluate in a patient’s clinical visit, we can better understand which patients are at highest risk for future medical problems and need preventative care.”   

The study was supported by a medical dermatology fellowship from the National Psoriasis Foundation and the National Institutes for Health (T32-GM075766, K24-AR064310-36).