Prepubertal gynecomastia is uncommon and idiopathic in over 90% of cases.
full report here.
Not infrequently, urologists may identify gynecomastia in children as part of a routine physical exam or in patients with gynecomastia specifically referred to rule out a testicular abnormality.
In the February 1st issue of the New England Journal of Medicine, Henley and colleagues from the University of Colorado report on 3 children whose gynecomastia resolved after stopping the use of lavender and tea tree oils. Both oils were tested on breast cancer cell lines to determine their interaction with the estrogen and androgen signaling pathways.
The first boy (age 4) presenting with worsening gynecomastia was found to have a normal testicular examination and hormonal profile. His gynecomastia resolved after his mother stopped applying a "healing balm" to the skin containing lavender oil. Another 10 year old boy presented with a 5 month history of gynecomastia and a normal evaluation. The areolar mounds disappeared 9 months after discontinuing the use of a hair styling gel containing Lavandula angustifolia (lavender) oil and Melaleuca alternifolia (tea tree) oil. The third boy age 7 years was evaluated for a 1 month history of gynecomastia and was found to be using lavender scented soap. His gynecomastia resolved several months after stopping the use of the soap.