Various adrenal disorders may cause premature sexual maturation.
However, this does not involve ‘gonadarche’ and so there is no breast development.

There is usually pubic and axillary hair development with associated cutaneous manifestations of acne, behavioural difficulties and an increase in growth rate with advance in skeletal maturation. Adrenal tumours may present with such symptoms, but they are usually of a rapid nature and more severe.

The clitoris is always enlarged. The serum testosterone is usually >5 nmol/l and it is not difficult to make the diagnosis of the presence of an adrenal tumour clinically. Imaging of the adrenal glands, initially using ultrasound but also CT, will usually reveal the lesion.

Congenital adrenal hyperplasia, of which the commonest form is 21-hydroxylase deficiency, usually presents in the neonatal period with ambiguous genitalia and a salt-losing crisis. However, milder forms of congenital adrenal hyperplasia may present in later childhood with virilisation. The clitoris is almost always enlarged. The diagnosis is made using a standard ACTH test and measuring adrenal metabolites in the blood, as well as the urine.

Simple adrenarche is a diagnosis of exclusion. This is a benign condition where there is pubic hair development, which usually commences between the ages of 5 and 7 years. It is self-limiting and the hair development is usually along the line of the labia majora and not on the mons pubis (as in normal puberty). The clitoris is normal.

The growth rate may be mildly accelerated, but this condition is not usually difficult to differentiate from an adrenal tumour or a biosynthetic adrenal steroid disorder. Simple adrenarche is a condition and not a disease, and requires reassurance and not treatment. The serum adrenal androgens are only mildly elevated, either towards the top, or just above, the normal range. However, recent data has suggested that there may be more sinister long-term sequelae for girls with simple adrenarche and this may be associated with the development of hyperinsulinism, obesity and polycystic ovarian disease in later life.