Doctors have blamed premature breast development in a toddler on the overuse of lavender products.
According to a report in the current issue of Medical Observer, endocrinologists at the Royal Children's Hospital in Melbourne first saw the then 14-month-old girl when her concerned parents brought her in with 2.5cms of bilateral breast tissue.
Despite the breast growth, the little girl showed no other signs of abnormal developmental milestones such as growth acceleration, acne, pubic hair or vaginal bleeding.
A number of tests were carried out on the toddler and returned with normal results, but the girl's breasts continued to grown another 0.5cm over the next 12 months, eventually measuring 3cm.
In a letter to the Journal of Paediatrics and Child Health, doctors told how the girl's parents had noticed their daughter's breast development from a very early age.
"The patient was born at term with a normal birthweight. From six months, her parents noticed increasing breast development," the authors wrote in the journal.
It was only after the girl's parents saw a documentary discussing a link between lavender oil and breast development that they revealed the extent of their use of lavender baby products to doctors.
"[The toddler's] daily exposure included lavender wipes (20 wipes/day), lavender shampoo (5ml alternate days), lavender body wash (5ml daily), lavender moisturising cream (10ml daily) and lavender skin soothing lotion (10ml daily). Specific lavender oil concentrations are unknown."
Past laboratory studies have suggested lavender oil can have an oestrogenic effect without causing elevation of actual oestrogen levels. These findings match the Melbourne toddler's case, as tests on her showed no elevation in oestrogen.
Doctors told how once the parents stopped using lavender products on the girl the growth stopped, and her breast tissue immediately receded.
It is not the first time lavender has been linked to abnormal breast development. A 2007 study looked at the cases of three healthy boys who began developing breasts.
None of the boys had yet reached the age of puberty and all had been using lavender products.
One of the boys was aged four and his mother had applied healing balm containing lavender oil to his skin shortly before his breasts began developing.
A 10-year-old boy had been using a hair-styling gel each day that contained lavender and tea tree oils.
The third boy, aged seven, had been using lavender-scented soap and skin lotions before his breasts developed - but his twin had been using the same products and didn't develop breasts.
According to a report in the New England Journal of Medicine, all of the boys' breasts receded once they stopped using lavender products.