Lichen planopilaris and thyroid disease: systematic review and meta-analysis

analysis of existing case-control studies to does not an association between LPP and any thyroid disease, hyperthyroidism or hypothyroidism. Our findings contradict those reported for lichen planus As such, this suggests that there are likely differences in the nuances underlying the pathogenesis of LPP versus lichen planus. Our study has several limitations. The included studies were mostly retrospective in design, thus susceptible to selection and assessment bias. The analysed effect sizes were unadjusted, and as such susceptible to influence by confounder variables. Large database studies may have errors in coding disease parameters, and there is heterogeneity in terms of criteria for diagnosis of thyroid disorders. Prospective studies with larger numbers of patients are required to reaffirm the findings in the present study.