Pediatric Examination and Board Review (119 page)

5.
(A)
Sexual maturity rating is an essential element in the evaluation of growth and development during the adolescent years. Because most linear growth in boys takes place during Tanner stages 3 and 4, the finding of a genital SMR 3 in this case should be reassuring about the potential for further linear growth. Anosmia (inability to perceive smells) and hyposmia are characteristically present in patients with Kallmann syndrome, and luteinizing hormone-releasing hormone (LHRH) deficiency leading to hypogonadotropic hypogonadism. This syndrome is often associated with mid-cranial and mid-facial anomalies. A thyroid examination, arm span, and upper/lower segment ratios should also be documented as a part of the evaluation of abnormal growth and development. Visual fields and fundoscopic examination may help exclude intracranial masses such as craniopharyngiomas, which may be responsible for pituitary and hypothalamic dysfunction.

6.
(D)
Constitutional delay of puberty is a diagnosis of exclusion. Even though the history is highly suggestive of this diagnosis, a CBC, sedimentation rate, complete metabolic panel, bone age, and a basic hormonal workup would help exclude some other conditions included in the differential diagnosis (chronic liver or kidney failure, chronic inflammatory disorders, inflammatory bowel disease (IBD), metabolic disorders, hypothyroidism, Cushing syndrome, etc). Insulinlike growth factor (IGF)-1 and insulinlike growth factor-binding protein (IGFBP)-3 are very helpful tests to screen for GH deficiency if the condition is suspected. Karyotype determinations are needed whenever clinical and/or laboratory findings point to the possibility of chromosomal anomalies.

7.
(B)
In constitutional delay of puberty, the bone age is delayed compared with the chronological age but closely correlates with the height age. In patients with familial short stature, the bone age typically corresponds to the chronological age and is usually advanced for height age. Delayed bone age occurs in adolescents with chronic illness, hypothyroidism, and hypopituitarism. Bone age is a helpful tool to determine potential linear growth.

8.
(E)
Bone maturation is controlled by thyroid hormone, estrogen, testosterone, and adrenal androgens. During puberty, an excess of these hormones leads to accelerated bone maturation, whereas their deficiency results in delayed bone age.

9.
(C)
Pubertal linear growth accounts for 20-25% of final adult height, averaging 12-13 inches in boys and 10-13 inches in girls.

10.
(C)
During peak height velocity (PHV), the average linear growth in boys is 10 cm/year (range: 5.8-13.1 cm). At PHV, girls grow an average of 9 cm/year (range: 5.4-11 cm). The average growth spurt lasts 24-36 months.

11.
(D)
In most girls, breast changes, including the development of breast buds and widening of the areolae, represent the first physical sign of puberty (B2). On average, pubertal changes are completed in 4 years with a range of 1.5-8 years. Peak height velocity in girls is attained between SMR 2 and 3 at an average age of 11.6 ± 1.2 years. Menarche, however, is a relatively late pubertal event and usually occurs at SMR 3 in 20% and at SMR 4 in 56% of girls. Menarche occurs in American girls at an average age of 12.4 years with a range of 9-17 years of age, usually 1 year after PHV is attained and 3 years after the start of the growth spurt.

In boys, testicular growth is usually the earliest physical sign of puberty (G2) and occurs at an average age of 11.6 ± 1 year (range: 9.5-13.5 years). The typical sequence in adolescent boys continues with adrenarche and further genital development, whereas PHV is a relatively late event, usually happening between SMR 3 and 4. Fertility is attained at SMR 4.

12.
(A)
The mean age of onset of puberty in boys is 11.6 years ± 1 year.

13.
(B)
Pubertal gynecomastia occurs in approximately 50% of normal boys during SMR 2-3. It usually appears at an average age of 13 and persists for 6-18 months. In boys with persistent gynecomastia, etiologies, such as hypogonadism, testicular tumors, hyperthyroidism, androgen resistance syndromes, and drug use, should be investigated.

Asymmetric gynecomastia is common. Facial acne at age 12 years would not be unusual in a normal boy who is undergoing adrenarche. Testicular size increases from an average prepubertal volume of 5.0 mL at the start of puberty to a final volume of approximately 19 mL by age 20 years.

14.
(E)
Constitutional delay of puberty is the most common cause of delayed puberty in boys. These boys eventually progress spontaneously through puberty. However, because CDP is a diagnosis of exclusion, the absence of any pubertal changes after the age of 14 years should prompt investigation to rule out other causes of delayed puberty. A thorough evaluation should include a detailed personal and family history, physical examination, review of growth charts, laboratory testing, and imaging studies. Characteristically, the bone age in boys with CDP closely approximates the height age and both are delayed in relation to chronological age. Usually a family history of pubertal delay is obtained from the parents, older siblings, or other family members.

15.
(B)
A BMI of 17-18% is necessary to reach menarche, and 22% is usually required to maintain regular menstruation.

16.
(B)
The criteria for presumptive diagnosis of CDP include absence of a history of systemic illness, evidence of adequate nutrition, normal findings on physical examination, including genital anatomy, sense of smell, upper to lower segment ratio, normal thyroid and GH levels, normal CBC, erythrocyte sedimentation rate (ESR), electrolytes and BUN, delayed bone age, and height at the 3rd percentile or less for age with annual growth rate velocity at the 5th percentile for age (at least 3.7 cm/year). A family history of CDP is often present but is not a necessary criterion for diagnosis.

17.
(D)
Early adolescence marks the beginning of the process leading from dependence on parents to independent behavior. Rapid physical changes will bring up an increased preoccupation with the self and uncertainty about one’s appearance and attractiveness. As the adolescent starts to detach from his/her parents, strong emotional bonds with peers develop, usually starting with friends of the same sex. Contact with teens of the opposite sex usually happens only in the context of groups of friends. Cognitive skills remain mostly concrete during early adolescence, but there is an increasing shift toward abstract thinking (formal operational thought). During this stage the adolescent strives toward self-definition and the development of a personal value system. This often leads to a testing of authority both at home and at school. Typically the development of a sense of omnipotence and invincibility leading to increased risk-taking behaviors emerges during middle adolescence.

S
UGGESTED
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EADING

Joffe A, Blythe MJ. Handbook of adolescent medicine.
Adolesc
Med.
2003;14:2.

Nathan BM, Palmert MR. Regulation and disorders of pubertal timing.
Endocrinol Metab Clin North Am.
2005;34:617-641.

Neinstein LS.
Adolescent Health Care. A Practical Guide.
5th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2007.

Rosenfield RL. Essentials of growth diagnosis.
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Clin North Am.
1996;25:743-758.

Tanner JM, Whitehouse RH. Clinical longitudinal standards for height, weight, height velocity, weight velocity, and stages of puberty.
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CASE 73: A 16-YEAR-OLD GIRL WHO HAS NEVER HAD A MENSTRUAL PERIOD

A 16-year-old white girl comes for the first time to the teen clinic because she has never had a menstrual period. She is a competitive gymnast who was homeschooled for several years so she could pursue her athletic career. She was recently diagnosed with a stress fracture for which she is undergoing physical therapy and is now taking a break from gymnastics. She has a history of asthma and uses an albuterol inhaler as needed but has never been hospitalized. Her growth and development have always been normal. On further questioning she states that her breast development started at age 12 and that now she wears a size 34B sports bra. She noticed pubic and axillary hair about 2-3 years ago. She has grown 1
¹
/
₂
inches during the past 18 months. Her mother recalls that her own periods started at age 13.

The family history is otherwise noncontributory. She denies trying to lose weight at this time but admits to being on a strict diet during the previous spring, around the time of a big gymnastic competition. At that time her weight went down to 105 lb. Now she is back on her usual diet and estimates her caloric intake at 2000 kcal/day. She considers herself to be slightly thin, although at times she wishes she could be a little thinner. She denies ever having been sexually active or using alcohol, tobacco, or other drugs. She states that she is usually stressed around the time of athletic competitions but that she has never been depressed. She is currently a tenth grader at a public school and is a straight A student. Review of systems is negative for headaches, nausea, vomiting, abdominal pain, dysuria, or vaginal discharge.

On physical examination, she is 5'5", 112 lb, has a heart rate of 72 bpm and a BP of 110/70 mm Hg. She is at Tanner stage 3 for breast and pubic hair development. The rest of her examination is unremarkable.

SELECT THE ONE BEST ANSWER

1.
Among adolescent girls, what is the average and SD age at menarche (in years)?

(A) 11.5 ± 1.2

(B) 11.8 ± 1

(C) 12.0 ± 1.5

(D) 12.7 ± 1

(E) 13.5 ± 1.2

2.
Which of the following statements is accurate?

(A) menarche occurs at sexual maturity rating (SMR) 3 in 60% of girls

(B) the peak height velocity is attained in girls before they reach Tanner stages B3 and PH2

(C) the average girl stops growing after menarche

(D) about 20% of girls start menses a year after attaining SMR 5

(E) the interval between menarche and regular periods is approximately 3 years