There is a significant positive correlation between psoriasis and hidradenitis suppurativa (HS), according to study results recently published in the Journal of the American Academy of Dermatology. The findings of the large-scale study support previous case reports and smaller studies that similarly note the coexistence of psoriasis and HS.
Investigators completed a cross-sectional population-based study to compare the prevalence of HS in patients with psoriasis across age-, sex-, and ethnicity-matched controls. The study included 68,836 patients with psoriasis and 68,836 control participants.
Results showed that HS prevalence was increased in patients with psoriasis when compared with the control participants (0.3% vs 0.2% respectively; odds ratio [OR] 1.8; 95% CI, 1.5-2.3; P <.001). When investigators adjusted for smoking, obesity, and other comorbidities in a multivariate analysis, the relationship persisted (OR 1.8; 95% CI 1.4-2.2; P <.001).
Compared with patients with psoriasis alone, those with a dual diagnosis of psoriasis and HS were younger (39.0 ± 15.7 vs 42.6 ± 21.2 years; P =.015), more likely to be obese (35.1% vs 25.3%; P =.001), and were smokers (58.5% vs 37.3%; P <.001).
Study limitations include a lack of data related to clinical features and severity of both psoriasis and HS. In addition, the classification of socioeconomic status was based on a poverty index rather than household income. Finally, the study was limited to Israeli patients and further longitudinal observational studies are necessary to confirm these findings in other populations.
Results of the study suggest that physicians treating patients with psoriasis should be mindful of the association between psoriasis and HS, and be aware that systematic therapies that treat both conditions may be preferable in patients with a dual diagnosis.
Kridin K, Shani M, Schonmann Y, et al. Psoriasis and hidradenitis suppurativa: a large-scale population-based study [published online November 28, 2018]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.11.036