Premature thelarche (PT) is a medical condition, characterised by isolated breast development in female infants.

[1] The exact cause of the condition is still unknown, but it has been linked to a variety of genetic, dietary and physiological factors.

PT occurs in pre-pubescent females, under the age of 8, having a peak occurrence in the first two years of life.

estrogen's role in PT, also leads to increased bone age and growth in some cases.

Diagnostic tests will distinguish these PT secondary symptoms from the more severe bone aging and growth occurring in early CPP.

[2] PT is linked to increased sensitivity of the breast tissue to estradiol, an estrogen derivative, in certain prepubertal individuals.

[1] Sporadic estrogen or estradiol production in the adrenal glands, follicles or ovarian cysts is also linked to the condition.

Gondotropin-releasing hormone (GnRH) stimulation testing in some patients with PT has shown a dominant response from FSH.

Partial activation would release a surplus of FSH from the anterior pituitary without further disruption of the HPG axis.

[2] PT is the benign growth of breasts in infants, while CPP is a condition that involves the frequent activation of the HPG axis in patients.

PT does not require treatment, as the condition is limited to enlarged breast tissue that usually subsides with time.

PT can impact growth velocity and bone age slightly, but CPP affects these characteristics to the point of detriment to the adult stature.

[1] The pelvis ultrasound is problematic as a diagnostic, as there is not a specific cut-off for the uterine and ovary volumes that indicate the patient has CPP.

The test is highly specific but has low sensitivity as the LH hormone response is usually observed in later stages of CPP.

[1] Natural commodities like fennel, lavender and tea tree oils have been linked to PT.

These estrogenic properties may cause an imbalance in endocrine signalling pathways, leading to PT in regular users of these products.

The tea contains fennel seed oil and regular use results in increased estradiol levels in the infant.

[6] The form of PT with fluctuating hypertrophy in patients has been linked to activating mutations in the GNAS1 gene.