High Body Surface Area of Severe Psoriasis Linked to Increased Risk of Developing PsA

In a large prospective cohort study, the body surface area (BSA) of patients with severe psoriasis was assessed to be a strong predictor of developing psoriatic arthritis (PsA) with obesity and depression being additive risk factors, according to a study in Rheumatology.

Data from a United Kingdom-based medical record database, The Health Improvement Network, was used in a prospective population-based cohort study to randomly select patients aged 25 to 60 years for inclusion between 2008 to 2011. Their general practitioners received questionnaires to confirm each patient’s psoriasis diagnosis and an approximate BSA. The BSA was then used to calculate the incidence of PsA, and the authors used Cox proportional hazard ratios (HRs) to examine the risk of developing PsA by BSA category after covariate adjustments.

Following administration, 9987 (95%) questionnaires were returned, with 9069 (91%) having confirmed psoriasis and 8881 providing a psoriasis BSA. Of those, 52% of patients had mild psoriasis, 36% moderate psoriasis, and 12% severe psoriasis. Analysis showed that the incidence of PsA was 5.4 cases per 1000 person years. Even after adjusting for age and sex, the authors found that BSA greater than 10%, BSA between 3% and 10%, obesity, and depression were all associated with an incidence of PsA.

Cardiovascular disease is one of the comorbidities already associated with increasing psoriasis severity. This study provided further data surrounding the association of psoriasis severity with developing PsA. Results concluded that BSA, obesity, and depression all influence the overall risk factor.

Reference
Ogdie A, Shin DB, Love TJ, Gelfand JM. Body surface area affected by psoriasis and the risk for psoriatic arthritis: a prospective population-based cohort study. Rheumatology (Oxford). Published online September 11, 2021. doi:10.1093/rheumatology/keab622