A 16-year-old boy attends your Physician clinic for the first time with his father. He has recently moved to the area. His father is concerned that he is shorter than his peers at school and he frequently complains about being bullied.
On further questioning there is no evidence of chronic illness or familial illness and he eats a balanced diet. His weight is on the 25th centile and his height is on the 10th centile. On examination he has no evidence of facial, axillary or pubic hair, his testes are both descended and are <4 mL volume.
What is the most likely cause of his delayed puberty?
A. Anorexia nervosa
B. Hypothalamo-pituitary dysfunction
C. Kallmann’ syndrome
E. Constitutional delay
ANSWER IS E The most common cause of delayed puberty is constitutional delay (E), although this is a diagnosis of exclusion. Delayed puberty is more common in boys. He does not have cryptorchidism (undescended testes) (D) on examination.
Although there is a history of bullying which may in turn lead to psychological problems including anorexia nervosa (A) rare in boys, but should be considered), his weight centile is greater than his height, making this unlikely though a body mass index should be calculated too (weight/height squared).
Kallmann’s syndrome (C) is characterized by low luteinizing hormone-releasing hormone and anosmia, which is not mentioned but this disease is rare (1 in 10 000– 86 000).
It is important to exclude hypothalamo-pituitary dysfunction (B) by measuring GnRH, LH and FSH but it is not the most likely cause.
Delayed puberty is defined by: In boys: the absence of testicular development (or a testicular volume lower than 4 ml) by age 14 years. In girls: the absence of breast development by the age of 13 years, or primary amenorrhoea with normal breast development by the age of 15.