Molluscum contagiosum is associated with atopic dermatitis and sexually transmitted infections in a matched case-control study using a national database.

Background: Molluscum contagiosum (MC) is a poxvirus that manifests as firm, smooth, dome-shaped, umbilicated, flesh-colored papules. In adults, MC is commonly spread by sexual contact, and is self-limited in patients with intact immune systems but more widely distributed and difficult to treat in immunocompromised persons. We analyzed cases of adult MC for associations with immunosuppression, lifestyle risk factors, and sexually transmitted infections (STIs).

Methods: Using the All of Us Research Program database, adults with MC were identified and matched with controls 1:10 based on demographic factors. Comorbidities, lifestyle risk factors, and medication exposures were analyzed. Odds ratios were calculated using logistic regression.

Results: Our analysis included 146 cases of adults with MC and 1460 demographic-matched controls. Patients with MC were 48 years old on average, 59% female, and majority White (82.5%). Controls were similar for all demographic features. Adults with MC were more likely to have syphilis (odds ratio (OR) 16; 95% confidence interval (CI) 2.57-99.5), human immunodeficiency virus (HIV) (OR 9.54; 95% CI 3.95-23.0), chlamydia (OR 6.24; 95% CI 2.38-16.4), condyloma acuminata (OR 13.9; 95% CI 7.36-26.2), genital herpes (OR 4.13; 95% CI 1.87-9.15), or atopic dermatitis (AD) (OR 2.85; 95% CI 1.5-5.4) (all p < .01). There were no differences in prevalence of other comorbidities, lifestyle risk factors, nor medication exposures (all p > .05).

Conclusions: We showed that adult MC is associated with AD and STIs, including HIV, chlamydia, condyloma acuminata, genital herpes, and syphilis. Sexually active adolescents and adults and those diagnosed with AD may be screened for MC and counseled on their potentially increased risk.