As the school year begins, many children might catch a stomach bug.
But, if the problem persists longer than the normal 24 to 48 hours, there may be an underlying problem: milk allergies or lactose intolerance.
Since both conditions have overlapping symptoms, parents often get the two confused. But they affect different systems in the body and call for different treatments.
Milk allergies reside in the immune system. When someone has a milk allergy, they are allergic to caseins and whey, the proteins found in cow’s milk. When they consume foods that contain these proteins, their immune system overreacts, causing allergic reactions that can lead to stomachaches, vomiting and diarrhea, typical lactose intolerance symptoms. But the reactions can also include wheezing, trouble breathing, coughing, hives, red spots, swelling or a rapid drop in blood pressure.
Dr. Mario E. Tano, a pediatric gastroenterologist with Joe DiMaggio Children’s Hospital in Hollywood, said milk allergies are more symptomatic in children and infants and should be closely monitored.
Although rare, children and adults with extreme milk allergies can experience a life-threatening reaction called anaphylaxis, which can lead to a state of shock and organ shutdown. Anyone diagnosed with a milk allergy should stay away from any foods with milk or milk proteins, such as casein, often used in cheeses, or whey, the watery liquid that separates from the solids in cheese making.
Parents should make a habit of reading the ingredients before giving food to their child. Even the slightest amount can cause a reaction in a child with allergies. For emergencies, doctors suggest children with food allergies keep an epinephrine pen with them at all times. If an allergic reaction occurs, a shot of epinephrine can stop it.
Dr. Alisa Muñiz Crim, a pediatric gastroenterologist at Miami Children’s Hospital, said many people mistake milk allergies with dairy allergies.
“There is a common misconception that if you’re allergic to milk, then you’re allergic to eggs, but that’s not true. You just have to avoid the proteins in milk, caseins and whey,” Muñiz Crim said.
Lactose intolerance has to do with the gastrointestinal tract and is less severe. It is more common among adolescents and adults and can be temporary. Lactose intolerance is the inability to digest lactose, a sugar that is found in milk and milk products. It is caused by a deficiency of an enzyme called lactate, which breaks down lactose into glucose and galactose, helping the bloodstream absorb the enzymes.
Children and adults who have lactose intolerance may experience symptoms when consuming milk or milk products, though they may be able to have small amounts depending on how severe their lactate deficiency is.
“Usually someone with lactose intolerance can tolerate about four ounces of milk a day, but it varies case by case,” Muñiz Crim said.
Symptoms typically last from 30 minutes to two hours and can range in severity depending on how much lactate the person’s body consumes. Tano said manmade enzymes such as lactate can help.
“For babies, there are formulas that are amino acid based and give them the calcium they need,” Tano said.
There are three types of lactate deficiency: primary, secondary and transient.
Primary lactate deficiency can usually begin around age 2, but can also be found in premature infants. This type of deficiency is also more common in Asians and African Americans, said Tano, who noted the deficiency can be hereditary.
“If you have a child that has lactose intolerance you should get tested for something else. Primary lactose intolerance is not as common, so something may be causing secondary lactose intolerance,” Muñiz Crim said.
Secondary lactate deficiency can be caused by other gastrointestinal illnesses such as Crohn’s, celiac disease or chemotherapy. Simple stomach bugs that cause infectious diarrhea can also cause temporary or transient lactate deficiency.
Lactose intolerance is typically diagnosed by having the patient refrain from consuming milk or milk products for a period of time and monitoring whether the symptoms go away. A doctor may perform a hydrogen breath test or a stool acidity test. The hydrogen breath test is used in children older than 5. During the test, the patient drinks milk and has their breath analyzed. Undigested lactose causes more hydrogen than normal and usually is a sign of lactose intolerance.
Stool acidity tests are used on infants and children under 5; the doctor checks for lactic acid or glucose in the stool, which are proof of undigested lactate.
“We can also measure a sample of their intestine, but we don’t do that unless we are testing for something else,” Muñiz Crim said.
Milk allergies are more difficult to diagnose and often require an allergist who will perform a series of blood or skin tests.
Since both of these conditions involve eliminating milk, a huge source of calcium and vitamin D, parents must be aware of the foods to substitute to ensure children are maintaining strong, healthy bones.
“In today’s world, most kids don’t like to eat green vegetables. But, they give a good amount of calcium. Okra, broccoli, tuna, almonds, soymilk and soybeans are all good foods that are rich in calcium. For kids with lactose intolerance, they can also drink lactate milk,” Tano said.
Muñiz Crim would add oranges for vitamin D, pinto beans and spinach to the list. She also said that if the child is not getting enough vitamin D in their diet, they should take a supplement.