Screening Tests for Children (Ages 2 to 12)

Without symptoms of disease, children generally do not need many laboratory screening tests. However, helping children develop healthy habits, like eating well and being active, could prevent serious and costly health problems as they grow older. For example, helping overweight or obese children reduce their weight can prevent diabetes and heart disease in later years.

Not every child may need screening for every condition listed here. Read the sections below to learn more about each condition and to determine if screening may be appropriate for a child.

Screening Recommendations

Diabetes

Most cases of type 1 diabetes are diagnosed under the age of 18. The signs and symptoms often develop rapidly and the diagnosis is often made in an emergency room setting. Thirty percent of new-onset cases of type 1 diabetes in children present with diabetic ketoacidosis. Thus, blood glucose measurements as screening for type 1 diabetes in asymptomatic children is presently not necessary. On the other hand, some youth with type 2 diabetes will have no obvious signs or symptoms of high blood glucose, especially early in the disease, and screening can be a useful tool. While still uncommon in children under age 10, the incidence of type 2 diabetes has increased dramatically in the last decade, especially in minority populations, according to the American Diabetes Association (ADA).

Developing the disease early in life means that the patient is at increased risk for the development of diabetic complications because of the potentially prolonged duration of exposure to high blood glucose (hyperglycemia). This increases the risk of serious health problems earlier in adulthood, such as heart disease, kidney failure, blindness, and foot amputations.

Risk Factors

Overweight, obesity, and physical inactivity are all contributing factors to development of type 2 diabetes, and they too have become national health problems. Parents and children should be aware that healthy eating habits and activity choices can lower an individual’s risk of developing type 2 diabetes and related complications later in life.

Recommendations

Consider screening overweight children who have 2 or more additional risk factors for diabetes every 3 years, starting at 10 years of age or at the onset of puberty if that occurs earlier.

Screen using one of the following tests:

• Fasting glucose (fasting blood glucose, FBG) – this test measures the level of glucose in the blood after an 8-12 hour fast.
• Hemoglobin A1c (also called A1c or glycated hemoglobin) – this test evaluates the average amount of glucose in the blood over the last 2 to 3 months and has been recommended as another test to screen for diabetes.
• 2-hour oral glucose tolerance test (OGTT) – this test involves drawing a fasting blood sample for glucose measurement, followed by having the person drink a solution containing 1.75 g of glucose per kilogram body weight to a maximum of 75 grams and then drawing another sample two hours after the person begins to consume the glucose solution.

If any of these results is abnormal, the test is repeated on another day. If the repeat result is also abnormal, a diagnosis of diabetes is made.

High Cholesterol

Beginning in childhood, the waxy substance called cholesterol and other fatty substances known as lipids begin to build up in the arteries, hardening into plaques that narrow the arterial passageways. During adulthood, plaque buildup and resulting health problems occur not only in the arteries supplying blood to the heart muscle but in arteries throughout the body (a problem known as atherosclerosis). For both men and women in the United States, the number one cause of death is heart disease, and the amount of cholesterol in the blood greatly affects a person’s chances of suffering from it.

Growing evidence shows that the biological processes that precede heart attacks and cardiovascular disease begin in childhood, although they don’t generally cause symptoms or lead to disease until middle age or later. Experts encourage physical activity and healthy eating in childhood and adolescence, limiting saturated fat and trans fat, to help protect against heart disease in adulthood.

Monitoring and maintaining healthy levels of cholesterol are important in staying healthy. Screening for high cholesterol, typically with a lipid profile, is important because there are usually no symptoms. A lipid profile usually includes total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides. Non-HDL-cholesterol can also be calculated by subtracting the HDL-C value from the total cholesterol result. Typically, fasting for 9-12 hours before having the blood sample drawn is required; only water is permitted. However, some laboratories offer non-fasting lipid profiles. In particular, children and teens may have testing done without fasting.

Since screening recommendations are not always consistent between healthcare organizations, it’s important to work with your children’s healthcare provider to develop a cholesterol-screening plan that is right for them.

Risk Factors

Family History: Youths are at increased risk if they have a parent, grandparent, aunt/uncle, or sibling who has high cholesterol or if they have a family history of cardiovascular disease (prior to age 55 in male relatives and age 65 in female relatives).

Personal Health: Youths are also at higher risk if they

• Are overweight or obese
• Have a diet high in fats, especially saturated or trans fat
• Get little or no exercise
• Have diabetes or hypertension (high blood pressure)
• Smoke cigarettes or use other tobacco products

Laboratory tests

• A blood test called can measure cholesterol levels. Before the test.
• Total cholesterol: a measure of the total amount of cholesterol in the blood. It includes both low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol.

Lead Poisoning

Lead is a metal that was once a common additive to household paint and leaded gasoline and was used in water pipes and as a solder in canned foods. Other local sources of lead may be areas near industrial or manufacturing sites.

A young child’s exposure to lead can damage the brain and other organs and cause behavioral problems and developmental delays. Even at low levels, lead can cause irreversible damage without causing physical symptoms, and impaired cognitive development may not be noticed until the child enters school.

Poisoning from this environmental hazard usually occurs in early childhood.

Recommendations

Universal screening or blood lead level tests are no longer recommended, except for children in high prevalence areas with increased risk factors.

The CDC uses a threshold blood lead level (BLL) of 5 mcg/dL (five micrograms per deciliter) to identify children living in environments that expose them to lead hazards. Any test results above this level should trigger lead management and monitoring. Any child who has an elevated blood lead level needs to have his or her home or other environment evaluated. Other people at the residence should be tested as well. Without the elimination or reduction of the source of the exposure – a lead hazard in the environment – the elevated lead level will likely recur.

Tuberculosis

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis bacteria. TB primarily targets the lungs but may affect any area of the body. It can be spread through the air from person to person through droplets of respiratory secretions such as sputum or aerosols released by coughing, sneezing, laughing, or breathing.

Most people who become infected with M. tuberculosis manage to confine the mycobacteria to a few cells in their lungs, where they stay alive but in an inactive form. This latent TB infection does not make the person sick or infectious and, in most cases, it does not progress to active tuberculosis. However, some people – especially those with compromised immune systems – may progress directly from initial TB infection to active tuberculosis. People who have HIV are much more likely to become sick if they contract TB. Another increasing concern is drug-resistant forms of TB that are resistant to the antibiotics typically prescribed to treat the disease.

According to the U.S. Centers for Disease Control and Prevention (CDC), TB in children is a public health concern because it is a marker for recent transmission of the bacteria, and infants and young children are more likely than older children and adults to develop life-threatening forms of the disease. Among children, the most cases of TB are seen in those under 5 years of age and in adolescents older than 10 years of age.

TB is one of the world’s deadliest diseases, although it is relatively uncommon in the U.S. Still, it is a large health issue among at-risk groups. Current guidelines call for targeted screening among such groups.

Recommendations

The American Academy of Pediatrics (AAP) recommends that children who are at risk of contracting TB have a tuberculin skin test, such as if

• They have been exposed to someone with active or suspected TB (e.g., a family member or other contact)
• They are immigrants from a country where TB is endemic or have traveled to those countries for more than one week

Iron Deficiency Anemia

Children grow and develop rapidly and need iron in their diet to develop normally. If a child does not consume enough iron, there is a risk of developing iron deficiency. Iron deficiency can cause anemia, a condition that can delay a child’s mental, motor, and behavioral development and create problems that last long after the iron level is raised to a healthy level. Poor motor skills, behavior problems at home and school, and poor performance in school can be the long-term consequences of not receiving enough iron as a young child (0 to 3 years of age).

Iron deficiency may also be due to a severe blood loss, a genetic disorder, or something interfering with the body’s ability to absorb iron, such as a medication the child is taking or a chronic illness (e.g., celiac disease).

The prevalence of iron deficiency and iron deficiency anemia in the Iranian children under 6 years of age is about 26.5% and 18% respectively.

Recommendations

It is recommended that children be screened with a hemoglobin and hematocrit test if they have risk factors for iron deficiency or iron-deficiency anemia.

Risk factors

Risk factors for iron deficiency anemia in young children may include:

• • Exclusive breastfeeding beyond 4 months of age without supplemental iron.
  • Households with a low income or living in poverty.
  • Drinking more than 24 ounces of cow’s milk per day after 12 months of age
  • History of:
    • Medications that interfere with iron absorption
    • Extensive blood loss
    • Restricted diet that doesn’t provide enough iron
    • Prematurity or low birth weight
    • Exposure to lead