A report was presented at the annual Pediatric Academic Society meeting describing how a preschool-age girl and her kindergarten-age brother began growing pubic hair.
This was not an isolated case; in 2004, there was similar cluster of five children, and previous clusters in outbreaks occurring along the lines of disease epidemics or environmental poisonings.
In 1979, there was an outbreak of breast enlargement among hundreds of Italian schoolchildren, most likely caused by estrogen contamination of beef and poultry.
Most commonly, these outbreaks traced to accidental drug exposures. But some physicians worry that children are at higher risk of early puberty due to the increasing availability of classes of drugs, cosmetics and environmental contaminants called endocrine disruptors.
In the case of the two children described in the report, their testosterone level was nealy100 times the normal amount. The cause was traced to a concentrated testosterone skin cream being used by their father. The children absorbed the testosterone through normal skin contact with their father.
Sex hormones like testosterone are particularly potent because they are easily absorbed through the skin and resist degradation. Other known triggers of early puberty have included a shampoo that contained estrogen and placental extract, shampoos containing lavender and tea tree oils, and industrial pollutants.