2025 – PAGE 64 – ADOLESCENT MEDICINE

DELAYED PUBERTY

DELAYED PUBERTY DEFINITION AND PEARLS

Delayed puberty is defined as the absence or incomplete development of secondary sex characteristics by the age of 13 for girls (look for breast buds) and 14 for boys (look for testicular enlargement), with some differences based on race and ethnicity. Pubic hair development is usually considered a sign of adrenarche, so it is not typically included in the definition.

PEARL: Unlike PREMATURE ADRENARCHE, delayed puberty is more concerning in girls, but less commonly diagnosed at the time of onset because “how many parents think it’s a bad thing that their little princess hasn’t had her period yet? They probably think it’s a blessing!”

PEARL: If TROPIN (LH and FSH) values are elevated (or normal), it’s likely a gonadal issue.

MNEMONIC: No breast buds by 13 is unlucky. Also, a 3 on its side looks like breast buds!

PRIMARY AND SECONDARY HYPOGONADISM

The two basic reasons for delayed puberty include:

• The gonads are not responding to FSH and LH by producing sex hormones (primary hypogonadism). In this case, FSH and LH will be elevated since there is no negative feedback to limit their production. Causes of primary hypogonadism (“faulty gonads”) include receptor problems, absent gonads, biosynthesis problems, Turner and Klinefelter syndromes, and so on.
• GnRH hormones (follicle-stimulating hormone–releasing hormone and luteinizing hormone–releasing hormone) have reduced or absent efficacy, leading to low (or normal) levels of FSH and LH (secondary hypogonadism). This category includes problems with the hypothalamus, pituitary, and thyroid.

This is analogous to hypothyroidism, where primary hypothyroidism is a problem with the thyroid gland itself, and secondary hypothyroidism is due to a lack of TSH, the stimulating hormone. As with the thyroid, HIGH STIMULATING HORMONES indicate that the end organ (thyroid or gonad) is having a problem producing the right amount of hormone.

PROLACTINOMA

Prolactinoma should be in your differential for a patient with DELAYED PUBERTY. Prolactin suppresses GnRH secretion and is therefore associated with decreased LH and FSH levels.

CONSTITUTIONAL DELAY OF PUBERTY

Bone age films that estimate an age that is younger than the true chronologic age would be consistent with a constitutional delay of puberty. The patient’s height is “normal,” but on a lower curve than expected (patient is short but probably not < 3rd percentile. In boys, 14–15 years old is considered delayed (“remember the CHOCOLATE HEART and the CAT he fell on—for precocious puberty?!?”). If bone age films are as mentioned above, it’s usually not treated with hormones. However, if asked which one could be used, the answer is TESTOSTERONE, NOT GROWTH HORMONE! In girls, 13–14 year old is delayed.

HYPOGONADOTROPIC OVARIAN FAILURE

For delayed puberty associated with hypogonadotropic ovarian failure, consider POOR NUTRITION or an EATING DISORDER as possible etiologies.