Failure to Thrive
Answer: D
A three-week-old boy with poor feeding, poor weight gain, vomiting, (and possibly inappropriate hyperpigmentation) is worth investigating, especially when “I got a letter” is elicited from the history. In California (as in most states), the newborn screening includes congenital adrenal hyperplasia. However, the assays have a two- to three-week turn-around time (perhaps longer if the parents are difficult to contact). This is a possible ED presentation.
Various enzymes are involved in the production of cortisol. If there is a congenital absence of these enzymes, there is no feedback from the adrenals to the hypothalamic-pituitary axis (HPA). With no negative feedback, ACTH is excreted by the HPA, which in turn acts on the adrenals. The result is a hyperplastic adrenal gland that is partially non-functioning due to the lack of enzymes needed to break down cortisol into various corticosteroids, mineralocorticoids, and sex steroids.
Baby girls can be more readily diagnosed in the nursery (before the screening labs) due to virilization. Baby boys can be overlooked, since they may outwardly appear normal; scrotal hyperpigmentation (which may or may not be present) can be an early clue. Treatment is geared towards the clinical presentation of the child – fluid resuscitation and correction of hyperkalemia, hypoglycemia, and acidosis are often required. Hydrocortisone administration in the ED may make this diagnosis more difficult, but the ill neonate should receive 25 mg IV, and the ill child should receive 50-100 mg hydrocortisone IV.
A three-week-old boy with poor feeding, poor weight gain, vomiting, (and possibly inappropriate hyperpigmentation) is worth investigating, especially when “I got a letter” is elicited from the history. In California (as in most states), the newborn screening includes congenital adrenal hyperplasia. However, the assays have a two- to three-week turn-around time (perhaps longer if the parents are difficult to contact). This is a possible ED presentation.
Various enzymes are involved in the production of cortisol. If there is a congenital absence of these enzymes, there is no feedback from the adrenals to the hypothalamic-pituitary axis (HPA). With no negative feedback, ACTH is excreted by the HPA, which in turn acts on the adrenals. The result is a hyperplastic adrenal gland that is partially non-functioning due to the lack of enzymes needed to break down cortisol into various corticosteroids, mineralocorticoids, and sex steroids.
Baby girls can be more readily diagnosed in the nursery (before the screening labs) due to virilization. Baby boys can be overlooked, since they may outwardly appear normal; scrotal hyperpigmentation (which may or may not be present) can be an early clue. Treatment is geared towards the clinical presentation of the child – fluid resuscitation and correction of hyperkalemia, hypoglycemia, and acidosis are often required. Hydrocortisone administration in the ED may make this diagnosis more difficult, but the ill neonate should receive 25 mg IV, and the ill child should receive 50-100 mg hydrocortisone IV.