The concurrent incidence of autoimmune comorbidities in obsessive–compulsive disorder (OCD) is known. However, the association between OCD and related autoimmune skin diseases (ASDs) has not been well studied.

This study aimed to investigate the association between OCD and the risk of ASDs.

To assess the risk of developing ASDs, we recruited 44 324 patients with OCD and 177 296 matched controls from the National Health Insurance Research Database in Taiwan. A Cox regression model was used for the analyses.

After adjusting for confounders, an increased risk of ASDs among the patients with OCD (adjusted hazard ratio [aHR]: 6.36; 95% confidence interval [CI]: 5.43-7.45) was found when compared to the controls. Statistically significant associations were found between OCD and seven individual ASDs, including psoriasis (aHR: 12.52; 95% CI: 8.78-17.85), lichen planus (aHR: 27.22; 95% CI: 13.09-56.60), alopecia areata (aHR: 13.69; 95% CI: 9.38-19.98), autoimmune bullous diseases (aHR: 4.30; 95% CI: 2.03-9.11), hidradenitis suppurativa (aHR: 29.95; 95% CI: 3.35-267.62), vitiligo (aHR: 9.35; 95% CI: 5.35-16.32), and lupus erythematosus (aHR: 2.10; 95% CI: 1.52-2.91).

Patients with OCD had an increased risk of developing ASDs compared to matched controls. Further studies are required to clarify the underlying mechanisms.