Precocious (Early) Puberty

What is precocious puberty?

Precocious puberty is the term for puberty that begins much earlier than usual. Puberty is the process in which a child has a growth spurt and develops the sexual physical features of an adult.

In the brain, the hypothalamus releases chemicals (hormones) that cause the pituitary gland to release hormones called gonadotropins. Gonadotropins stimulate the growth of the sex glands (also called gonads), which in boys are the testicles, and in girls are the ovaries. In boys, the testicles release testosterone; in girls, the ovaries release estrogen. Puberty usually starts between the ages of 8 and 13 in girls and 9 and 14 in boys.

Children affected by precocious puberty undergo this process much earlier: girls develop secondary sexual characteristics, like breasts, before age 8, and boys with precocious puberty have changes before age 9.

What are the types of precocious puberty?

There are three types of precocious puberty that may affect a child: central precocious puberty (the most common type), peripheral precocious puberty and incomplete puberty.

• Central precocious puberty: Central precocious puberty occurs when sex hormones are released too early. Central precocious puberty can be caused by brain trauma, tumors of the hypothalamus, or certain infections of the brain. In many cases, especially in girls, the reason for the early release of sex hormones is unknown.
• Peripheral precocious puberty: Peripheral precocious puberty occurs as a result of problems with reproductive organs (ovaries or testicles) or the adrenal glands, or from hormone exposure from the environment. The adrenal glands are part of the endocrine system and produce hormones the body needs to carry out daily functions. Adrenal glands are located above each kidney and are about the size of a thumb.
• Incomplete puberty: Incomplete puberty is a condition in which a child has just a few signs of early puberty, such as breast development in very young girls and growth of the body hair in girls or boys. Early body hair can appear when the adrenal glands produce extra androgens.

Who is affected by precocious puberty?

Any child can develop precocious puberty. The condition happens more often in girls than in boys.

How common is precocious puberty?

Early puberty affects an estimated 1 in 5,000-10,000 girls. The incidence of precocious puberty in boys is unknown.

What causes precocious puberty?

Precocious puberty can have different causes, depending on the sex of the child, age of onset, and other factors. In most cases, the causes of central precocious puberty in girls are unknown, but it can be treated effectively.

Precocious puberty at younger ages, and in boys, may be more likely to have an identifiable cause; for instance, if children are exposed to reproductive hormones from sources outside the body, such as from products like estrogen or testosterone creams or other chemicals in the environment.

What are the signs of precocious puberty?

The signs and symptoms of precocious puberty in both boys and girls include acne, body odor and a growth spurt. Precocious puberty also causes sexual characteristics to develop early. In girls, these include:

• Breast development.
• Menstruation.
• Pubic and underarm hair.

Early puberty in boys may cause:

• Deepening voice.
• Facial, pubic and underarm hair.
• Enlargement of the penis and testicles.

How is precocious puberty diagnosed?

The doctor will perform a physical examination and get the child’s medical history. The doctor may order X-rays of the hand to check how mature the child’s bones are. Overproduction of the reproductive hormones causes bones to mature earlier than normal, which suggests precocious puberty.

The doctor may also order blood work to measure hormone levels. If more tests are needed, the doctor may recommend a brain MRI. This test can help rule out brain abnormalities, such as tumors.

Pelvic ultrasound (a test that sends high-frequency sound waves through body tissues to create images of the internal structures of the body) can show cysts or tumors on the ovaries. These growths sometimes cause early puberty in girls.

How is precocious puberty treated?

For many children, medications can manage precocious puberty. These medicines include synthetic (man-made) hormones that work by halting the production of reproductive or growth hormones.

Some children need surgery to remove a tumor or other mass that may be causing the symptoms of early puberty. Removing an outside source of reproductive hormones, such as estrogen creams, may be enough to stop early puberty.

What complications are associated with precocious puberty?

Early puberty may cause a growth spurt in a child, but when puberty ends, the child stops growing. Therefore, he or she may be shorter than other children of the same age. Precocious puberty may also be embarrassing for children who are developing more quickly than other children.

Can precocious puberty be prevented?

Most cases of early puberty cannot be prevented. Limiting your child’s exposure to reproductive hormones from outside sources may prevent precocious puberty. These sources may include estrogen or testosterone creams, lotions, or other medications.

What is the prognosis (outlook) for people who have precocious puberty?

Treatment using medications or surgery usually stops precocious puberty. This treatment allows a child to develop normally.

When should I call my doctor about precocious puberty?

Talk to your doctor if your child shows signs of precocious puberty, especially if the child is younger than 10.