Differential Diagnosis for a 1-Month-Old Boy with Scleral Icterus and Hoarse Cry
- Single Most Likely Diagnosis
- Congenital Hypothyroidism: The patient's symptoms, including a weak suck, large protruding tongue, hoarse cry, and jaundice, are classic for congenital hypothyroidism. The laboratory results, particularly the elevated TSH (110 µU/mL) and low serum T4 (0.6 µg/dL), strongly support this diagnosis. Congenital hypothyroidism is a common cause of jaundice and feeding difficulties in newborns.
- Other Likely Diagnoses
- Biliary Atresia: Although the direct bilirubin is not significantly elevated, biliary atresia could still be considered, especially with the presence of jaundice. However, the other symptoms and laboratory results are more suggestive of congenital hypothyroidism.
- Congenital Infections (e.g., TORCH infections): These infections can cause jaundice, feeding difficulties, and other systemic symptoms. However, the specific combination of symptoms and laboratory results in this case makes congenital hypothyroidism more likely.
- Do Not Miss Diagnoses
- Congenital Pituitary Hypoplasia or Hypopituitarism: Although less likely, these conditions can present with similar symptoms, including hypothyroidism, and are critical to diagnose due to their potential impact on growth and development.
- Thyroid Dysgenesis with Ectopic Thyroid: This condition can cause congenital hypothyroidism and may require specific imaging studies for diagnosis.
- Rare Diagnoses
- Pendred Syndrome: A genetic disorder that can cause congenital hypothyroidism, hearing loss, and other symptoms. It is less likely but should be considered in cases where congenital hypothyroidism is diagnosed, especially if there are additional symptoms such as hearing loss.
- Resistance to Thyroid Hormone: A rare condition where the body is resistant to thyroid hormone, leading to elevated TSH and variable symptoms. It is less likely given the patient's presentation but could be considered if initial treatment for congenital hypothyroidism is ineffective.