Psoriasis occurs in both men and women at fairly equal rates, but several studies have found there are differences between the sexes in regard to treatment. Men are more likely to be represented in psoriasis registries, and they consume more care for their psoriasis. Is this because men have worse psoriasis than women? Or are they just more likely to get certain treatments? One recently published study investigated the reasons behind these differences.
The research team’s goal was to investigate the differences between the sexes in the severity of psoriasis. They used the national registry of psoriasis in Sweden, which included 5,438 patients who have moderate to severe psoriasis. Each patient was evaluated using the clinical tool the Psoriasis Area and Severity Index (PASI).1
Scoring the severity and extent of psoriasis
PASI is a tool that expresses the extent and severity of psoriasis in a numeric way. The severity is calculated from 0 to 4 across several characteristics: the redness (erythema), thickness (induration), and scaling (desquamation). If the characteristic isn’t present, the score is a 0. Mild psoriasis characteristics are rated 1 and severe are rated 4.
Four regions of the body – the head, trunk (chest and abdomen), arms, and legs – are also rated based on how much of the region is covered with plaques, from 0 to 100%. The PASI calculation multiplies the scores from the severity and the area affected and weights them according to how much of the body is affected (the head is a much smaller area than the legs, and so would be a smaller portion of total).2 (There are free PASI applications online at http://pasi.corti.li/ and http://www.pasitraining.com/calculator/step_1.php.)
Who has it worse – men or women?
In the Swedish study, women had a statistically significantly lower PASI score average than men – the average for women was 5.4 and the average for men was 7.3. This difference was consistent across all age groups and all areas of the body except one: One area where the women had psoriasis worse than men was the head.1
What does it mean?
The statistical analysis in the Swedish study suggests that the reason men are more likely to be represented in registries and are getting more treatment is because of the difference in severity between the sexes. If men, in general, have more severe disease, they would be more likely to receive systemic treatments for their psoriasis.1
This study didn’t focus on the “Why” behind the difference in severity, and additional studies will have to uncover the reasons men have more severe psoriasis. The study authors also noted that their findings are significant and should spur additional research into the management of psoriasis in different genders, as well as the prevention and management of other health conditions that are linked to psoriasis.1
Hägg D, Sundström A, Eriksson M, Schmitt-Egenolf M. Severity of psoriasis differs between men and women: a study of the clinical outcome measure Psoriasis Area and Severity Index (PASI) in 5438 Swedish register patients. Am J of Clin Dermatol. 2017 Aug;18(4):583-590. doi: https://doi.org/10.1007/s40257-017-0274-0
Psoriasis Area & Severity Index. PAPAA. Available online at http://www.papaa.org/articles/psoriasis-area-severity-index. Accessed 2/27/18.