Guttate Psoriasis As a Prognostic Marker for Plaque Psoriasis

The first guttate psoriasis (GP) episode, which is often triggered by an acute infection such as streptococcal pharyngitis, often results in patients developing chronic plaque psoriasis, according to research presented at the 73^rd American Academy of Dermatology Annual Meeting.

Researchers had typically believed GP would have a better prognosis and show rapid resolution, but there have been few studies that sufficiently address the long-term outcomes and likelihood of developing chronic plaque psoriasis (PP).

As such, a retrospective study led by Lisa Pfingstler, MD; Michele Maroon, MD; and Christen Mowad, MD, from the Dermatology Department of Geisinger Medical Center, Danville, PA, compared clinical and laboratory data from patients with GP who developed PP with data from those who did not.

Using electronic medical record data from January 2000 to September 2012, researchers found charts that had a diagnosis of either “dermatitis” or “psoriasis” and a positive strep molecular probe or the specific clinical diagnosis of GP.

Additionally, they performed a separate search of the co-path database for biopsy-proven GP, and determined the prevalence of developing chronic plaque psoriasis among the GP patient group.

Of a total dataset of 79 GP patients who had at least 1 year of follow-up history, 20 patients (25.3%) were found to have developed PP, while 59 (74.7%) did not.

Interestingly, patients who had a strep molecular probe and developed PP were less likely to have a positive strep molecular probe than patients who did not develop PP.

After the observation period ended, the researchers noted that the patients who developed PP were more likely to develop a case of GP that never cleared than patients who didn’t develop PP (15.8% vs. 1.7%, p = .0428).

The researchers noted no differences between groups “with respect to family history of psoriasis, treatments for GP, smoking status, or history of metabolic syndrome.”

The team concluded, “Testing for Group A streptococcus may serve as a useful prognostic tool. These results are important to help counsel patients with GP on the expected course of their disease.”