American Medical Association Family Medical Guide - American Medical Association [181]
Symptoms
The symptoms of hypothyroidism in an infant can include poor appetite, constipation, fatigue, slow heart rate, poor circulation, slow growth, and delayed physical and mental development. An infant with hypothyroidism also may have characteristic facial features, including wide-set eyes, a flat nose, and a large tongue. When hypothyroidism develops later in childhood, the symptoms can include muscle weakness and cramps, fatigue, difficulty concentrating, very dry skin, hoarseness, hair loss, and weight gain.
Diagnosis and Treatment
All newborns in the United States are screened soon after birth for thyroid abnormalities. If the test results indicate inadequate blood levels of thyroid hormones, a doctor performs additional tests to determine the cause. In some cases, a doctor may order an MRI (see page 113) to check for a pituitary tumor.
Hypothyroidism is treated with replacement thyroid hormone (in the form of thyroxine) taken orally every day for life. Blood tests are performed regularly to measure the level of thyroid hormone in the blood. The doctor will adjust the dose of thyroid hormone as needed.
When hypothyroidism is detected in the first few days of life, the outlook is excellent. Children treated with replacement thyroid hormone from birth develop normally, both physically and mentally.
Disorders of the Digestive System
While in the uterus, the fetus receives all of its nutrients from the mother through the placenta and umbilical vein. Because a baby does not use its digestive system until after he or she is born, malformations of the digestive system that occur during fetal development do not affect the baby until after delivery.
The two main types of malformations that can affect an infant’s digestive system are stenosis (narrowing of a tube or duct, sometimes almost to the point of closing) and atresia (blockage in a tube or duct that separates it into two distinct, sealed-off sections). The causes of these defects are not known.
Although any abnormality in the digestive system can affect an infant’s ability to digest food and absorb nutrients, these abnormalities also can pose some other risks. For example, in digestive system disorders that cause vomiting, a baby may inhale the vomit, which can lead to choking or pneumonia. Disorders that cause vomiting and diarrhea can lead to life-threatening dehydration.
Meckel’s Diverticulum
Meckel’s diverticulum is a congenital (present at birth) disorder in which an abnormal sac, usually lined with gastric (stomach) tissue, forms near the final part of the small intestine (ileum). Meckel’s diverticulum occurs in about 1 in 50 children and affects more males than females. The disorder usually does not cause symptoms unless the diverticulum is obstructed, infected, or bleeds from sores in the diverticulum. Stomach acid from the stomach tissue causes the sores, which can bleed severely. If inflammation is severe, the sac can rupture and cause an abscess (a pus-filled cavity) or inflammation of the lining of the abdominal cavity (peritonitis; see page 759). Sometimes Meckel’s diverticulum causes a condition called intussusception (see next page), in which the intestine folds back on itself like a telescope. Intussusception occurs more often in infants and young children than in adults.
Symptoms and Diagnosis
The symptoms of Meckel’s diverticulum include bleeding from the rectum (the blood is dark reddish brown) and sometimes abdominal pain or vomiting, or, rarely, fever. The condition can be difficult to diagnose because the symptoms are similar to those of other disorders such as an intestinal obstruction (see right), appendicitis (see page 771), or a perforated duodenal ulcer (see page 755).
If a person has symptoms