When puberty arrives too early or too late

For many children, puberty is the beginning of the shift from childhood to adolescence, but what if child shows signs of puberty before the typical age or what if the teenager hasn’t gone through it? A session at the virtual 2021 American Academy of Pediatrics National Conference & Exhibition led by Paul Kaplowitz, MD, PhD, emeritus professor of pediatrics at Children’s National Hospital in Washington, DC, covered the variations in abnormal pubertal development.

A wide variation in normal puberty timing exists with a range of 8 to 13 years of age for girls and 9 to 14 years of age for boys. Progressive breast growth is the first reliable sign of puberty for girls and enlargement of the tests followed by growth of the penis are the first signs for boys. Pubic hair and presence of body odor are not reliable signs of puberty. Hormones that play a role in puberty are the luteinizing hormone (LH) and follicle-stimulation hormone (FSH) and the sex steroids, either estradiol or testosterone, which are responsible for the physical changes and growth spurt. Kaplowitz did note that there have been multiple studies showing girls with common signs of puberty before 8 years of age.

Variations in early pubertal development include premature adrenarche, genital hair in infancy, premature thelarche, prepubescent vaginal bleeding, and precocious puberty. Premature adrenarche is the common cause for early puberty referrals. It typically presents with pubic hair and underarm odor, without breast development in girls or testicular or penile growth in boys. Laboratory screenings and bone age x-rays are not required and it can be monitored in the primary care office. Benign genital hair of infancy presents as fine, dark hairs along the labia or scrotum in the first year of life and is more common with girls. The hair will either regress, stay the same, or increase. Referral is not necessary, but can be done if caregivers require reassurance. Premature thelarche presents as nonprogressive breast development before 2 years of age. It rarely progresses to precocious puberty and lack increase should be reassuring. It can be monitored in the primary care office and laboratory testing is not required. Prepubertal vaginal bleeding in girls age 3 to 9 with no breast development is generally a benign, self-limited condition, if the exam is negative. If it persists or worsens, pediatric gynecology may helpful for a consult.

Central precocious puberty should be suspected if there has been a sustained increase in breast tissue over at least 4 to 6 months in girls and enlargement in both the testes and penis for boys. If central precocious puberty is suspected, screenings should be left to the pediatric endocrinologist. If there is concern or the appointment with specialist is delayed, then the only tests needed are LH, FSH, and either estradiol or testosterone. There is no need for thyroid testing. The main medical indication for treatment is potential loss of adult height, but most children with central precocious puberty attain it without treatment. The most common reason for caregivers to desire treatment for girls is worry over the child’s ability to cope with early onset of menstruation. Treatment is very expensive and should be reserved for patients who will derive the most benefit.

On the other hand, delays in puberty are experienced by 2% to 3% of children. The most common form of puberty delay is constitutional delay of growth and puberty and it’s the most common reason for delay in boys. Roughly two-thirds of patients will have at least 1 parent who was late maturing. Although the patient may be shorter than peers at the beginning of adolescence, a growth spurt near the end of high school will remove the deficit. A look at bone age can be helpful and is often delayed by 2 years. For families that want treatment, 4 monthly injections of depot testosterone can be prescribed for increased growth rate and secondary sex characteristics, which will result in pubertal progression and testicular growth within 4 months of ending the treatment. However, it should be noted that untreated patient will also progress, just more slowly. Klinefelter syndrome presents with adequate penile growth and pubic hair for age, but small testicular volume. Both FSH and LH will be elevated by age 14 years. Testosterone may be used for treatment, but may not be necessary unless the level is clearly low (< 200 ng/dl). For girls, Turner syndrome is a common cause for delay. Physical characteristics include a webbed neck, low set ears, and a highly arched palate. However, those characteristics may not be found in patients with mosaicism.

Reference

1. Kaplowitz P. Too early, too late: normal and abnormal variations in pubertal development. American Academy of Pediatrics 2021 National Conference & Exhibition; virtual. Accessed October 9, 2021.