Lichen planopilaris is associated with prior herpes simplex virus, helicobacter pylori, and human papillomavirus in large retrospective cohort

Summary: Abstract Body: Lichen planopilaris (LPP) is a scarring cicatrical alopecia type with female predominance. The pathogenesis of LPP is incompletely understood. It has been postulated that infectious agents, may be potential risk factors. Thus, we investigated for potential associations between LPP and viral and bacterial infectious agents using a large database. TriNetX research network was searched for female LPP patients 0-90 and controls without LPP and for female patients with and without prior infections. Cohorts were propensity score matched for age, race/ethnicity. Prevalence of prior infections were collected for LPP vs. control patients. Odds ratios of developing LPP ≥1 day after different infections were calculated. A total of 21,967 LPP and 21,967 matched controls were included. Demographics were similar between cohorts after matching (P>0.05). LPP vs. matched control patients had higher prevalence of prior HSV (2.77% vs. 1.72%, P<0.001), low-risk HPV (1.36% vs. 1.07%, P=0.006), Helicobacter pylori (0.96% vs. 0.34%, P<0.001), high-risk HPV (0.83% vs. 0.56%, P<0.001), HCV (0.37% vs. 0.07%, P<0.001), and syphilis (0.05% vs. 0%, P=0.002). Patients with prior HSV (OR=2.88, 95% CI 2.44-3.41), Helicobacter pylori (2.20, 1.71-2.84), and high-risk HPV (1.80, 1.40-2.30) infections had higher odds of developing LPP vs. matched controls without prior infections. Our study was limited by ICD-10 coding and their accuracy without molecular or histopathological confirmation. We found increased prevalence of prior HCV, Helicobacter pylori, HSV, HPV, and syphilis infections in LPP patients vs. matched controls, and higher odds of LPP with prior HSV, Helicobacter pylori, and high-risk HPV infections. Our findings suggest that prior infectious agents may be a risk factor for LPP. Amit Singal¹, Michael Ong², Shari Lipner³ 1. Rutgers New Jersey Medical School, Newark, NJ, United States. 2. MD Program, Weill Cornell Medicine, New York, NY, United States. 3. Department of Dermatology, Weill Cornell Medicine, New York, NY, United States. Clinical Research: Epidemiology and Observational Research