Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils

Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils
The New England Journal of Medicine, Feb 1, 2007.



SUMMARY
Most cases of male prepubertal gynecomastia are classified as idiopathic. We investigated possible causes of gynecomastia in three prepubertal boys who were otherwise healthy and had normal serum concentrations of endogenous steroids. In all three boys, gynecomastia coincided with the topical application of products that contained lavender and tea tree oils. Gynecomastia resolved in each patient shortly after the use of products containing these oils was discontinued. Furthermore, studies in human cell lines indicated that the two oils had estrogenic and antiandrogenic activities. We conclude that repeated topical exposure to lavender and tea tree oils probably caused prepubertal gynecomastia in these boys.


GYNECOMASTIA IS GENERALLY ATTRIBUTED TO CONDITIONS THAT DISrupt sex-steroid signaling pathways, resulting in increased or unopposed estrogcn action on breast tissue.1 In contrast to gynecomastia in adolescent boys and men, prepubcrtal gynecomastia is rare and should always be considered pathological, prompting a search fora 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 healthy boys with normal serum concentrations of endogenous steroids.