Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils

Three otherwise healthy prepubertal boys with normal endogenous steroid levels had gynecomastia coincident with the topical application of products containing lavender and tea tree oils. Gynecomastia resolved after the use of these products was stopped. Studies in human cell lines indicated that both oils exhibited estrogenic and antiandrogenic activities, suggesting that repeated topical exposure probably caused prepubertal gynecomastia. Three otherwise healthy prepubertal boys with normal endogenous steroid levels had gynecomastia coincident with the topical application of products containing lavender and tea tree oils. Gynecomastia is generally attributed to conditions that disrupt sex-steroid signaling pathways, resulting in increased or unopposed estrogen action on breast tissue. 1 In contrast to gynecomastia in adolescent boys and men, prepubertal gynecomastia is rare and should always be considered pathological, prompting a search for a source of estrogen. Although hyperestrogenemia may be endogenous or exogenous in origin, most persons with prepubertal gynecomastia have normal serum concentrations of sex steroids, and an underlying cause is not identified. 2 , 3 In such cases, possible exposure to exogenous sources of estrogen should be considered. We investigated the cause of prepubertal gynecomastia in three otherwise . . .