Is Your Kid Lactose Intolerant or Allergic to Milk?

Plus, how to be sure your kid gets the nutrition they need.

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Tummy issues in kids are common, but sometimes, there may be something more at play than just a little acid upset or gas. Underlying causes, like food allergies or intolerances, may be to blame—but the potential symptoms, severity, and risks between an allergy and intolerance are quite different. The most common culinary culprit in infants and young children is milk, or more accurately, a naturally-occurring sugar found in it called lactose.

Though lactose intolerance symptoms are not as serious as those that arise from a full blown allergy, they can be uncomfortable and bothersome for your little one. Not to mention a challenge when it comes to trying to put together healthy snacks and mealtimes (especially if you’re trying to introduce new foods to your baby or find yourself in constant standoffs with a picky eater).

To learn more about lactose intolerance signs in babies and older children, keep reading. We’re diving into what causes lactose intolerance, how it differs from a milk allergy, and how to be sure your kid still gets all the nutrition they need. Plus, you’ll find out if it’s possible for your baby to have an intolerance to your breast milk.

What Is Lactose Intolerance?

From birth, an enzyme called lactase is usually present in babies’ digestive systems—specifically in their intestines—which breaks down the lactose in milk (breast milk and formula) and milk-derived products. However, if there’s not enough lactase present, their bodies have a more difficult time processing lactose, which can lead to lactose intolerance and its hallmark uncomfortable digestive symptoms.

Since milk is the first thing they consume, babies who are born full-term naturally have higher levels of lactase in their system, which gradually decrease as they get older. This is why a diagnosis of baby lactose intolerance is relatively uncommon, and signs of lactose intolerance are more likely to show up after the age of 3 (and potentially become more problematic during the teenage years and adulthood). Still, despite infant lactose intolerance technically being less common than in older populations, lactose intolerance, in general, shouldn’t be underestimated: All in all, it’s estimated that 30 to 50 million Americans are lactose intolerant.

When it comes to preemie babies, while most can digest lactose just fine, being born early does put them at a slightly higher risk of developing infant lactose intolerance simply due to an insufficient amount of lactase in their system. Known as “developmental lactase deficiency,” this condition usually resolves itself shortly after birth as their tiny bodies (and digestive systems) develop.

Genetics also plays a role in someone’s susceptibility to lactose intolerance. And certain diseases or injuries can impede the production of lactase for a short while as well. In extremely rare cases, it's possible to come into this world without the ability of your digestive system to make any lactase at all.

What Is the Difference Between a Cow's Milk Protein Allergy (CMPA) & Lactose Intolerance?

It can be easy to mistake a food intolerance—like milk—that bothers your kid’s tummy for an allergy. But there’s a distinct difference between food intolerances and allergies, which all comes down to which physiological systems are causing the reaction(s). Since lactose intolerance is caused by a lack of the enzyme lactase, issues with digestion and metabolism are what lead to tummy disturbances and discomfort. A milk allergy, on the other hand, is a reaction caused by the immune system, in which the body misinterprets lactose as a threat, then sets out to attack it—causing potentially serious and/or life-threatening allergic reactions in the process.

Lactose Intolerance Symptoms vs. Milk Allergy Symptoms

Lactose intolerance symptoms and signs of a milk allergy can vary greatly from kid to kid, including how long after consuming milk or milk derivatives they may arise. But since many symptoms can overlap food intolerances and allergies, it’s always best to get a proper diagnosis from your pediatrician or an allergist to be sure.

Lactose intolerance symptoms may be seen anywhere from half an hour to two hours after ingestion of milk or milk-based products. And their intensity may also vary, depending on how much lactose was consumed versus how much lactase your little one’s body makes. Lactose intolerance signs include:

  • Belly cramps and/or pain
  • Bloating
  • Nausea
  • Diarrhea
  • Gas

If your infant is diagnosed with and experiencing signs of lactose intolerance, as opposed to a milk allergy, you can help relieve gassiness and bloating with Infants’ Mylicon Gas Relief Drops in either our dye-free or original formula. They work fast to break down gas bubbles to help your baby naturally release them. For kids ages 2 to 11, try Children’s Mylicon Tummy Relief in liquid or chewable tablets. In addition to gas and bloating, it will help quickly relieve acid indigestion and discomfort from overeating. Whichever product you choose, just follow the dosage instructions on the packaging.

Mommy Pro Tip: To help support healthy digestion overall, as well as immunity, try our Infants’ Mylicon Daily Probiotic Drops. (Bonus: If your baby is colicky, they’ve been shown to help reduce crying and fussiness by 50% or more over time.)

Symptoms of a milk allergy can also differ kid to kid. They may occur as quickly as a few minutes after ingesting food or a drink with lactose in it, or not show any signs for a few hours. And, since an allergic reaction may escalate to dangerous levels fast, it’s best to talk to your pediatrician, allergist, or emergency personnel as soon as possible.

First signs of a milk allergy can include:

  • Hives
  • Itchiness or tingling around their lips or mouth
  • Vomiting
  • Wheezing
  • Coughing
  • Shortness of breath

Potentially more delayed, but serious signs may be:

  • Crying & fussiness (in infants)
  • Watery eyes
  • Runny nose
  • Tummy cramps
  • Loose stools or diarrhea (which may contain blood)
  • Anaphylaxis (itchiness, swelling of the face and/or throat, difficulty breathing, facial flushing, or shock, all of which require immediate medical attention)

How To Diagnose Lactose Intolerance In Babies & Infants

Only a doctor or allergist can accurately diagnose lactose intolerance in your child, so it’s always best to speak with them as soon as you suspect there may be an issue. You’ll be asked to provide your and your family’s medical history. Then, they’ll measure how your child’s body processes (or struggles with) lactose, typically via the following diagnostic routes.

1. Eliminating milk & milk derivatives: By holding off on giving your kid any milk or milk-based products for a period of time, it will be easier to see if their symptoms clear up. Aside from checking to see if milk or lactose are listed on nutrition labels, also keep a look out for milk derivatives such as the more obvious dry milk solids or nonfat dry milk powder, as well as the more obscure ones like curds and whey.

2. Lactose intolerance test: As the name suggests, this test directly checks how well your kid’s system processes lactose by having them drink a lactose-laced liquid on an empty stomach, then taking some blood samples over a 2-hour period. One of these, in particular, will check the level of sugar in your child’s system after drinking the liquid. (Remember: Lactose is a form of sugar. If your kid’s blood sugar rises, it indicates that they’ve metabolized it. If it doesn’t, that’s indicative of an issue processing it—i.e. lactose intolerance.)

3. Stool acidity test: If your child’s body is struggling to digest lactose, levels of lactic acid, glucose, and other fatty acids will be detectable in their poop.

4. Hydrogen breath test: Likewise, if your child has issues digesting lactose, the sugar will become fermented by bacteria in their system, which will then produce an array of gasses, such as hydrogen. These can be measured with periodic tests in the hours following consumption of milk or milk-based products, with high levels indicating potential lactose intolerance.

Does Breast Milk Have Lactose?

Similar to milk from other mammals, such as cows and goats, your breast milk contains lactose—which accounts for about 7% of its makeup. So, if you breastfeed and your baby is lactose intolerant, then, yes, they could have a reaction to the lactose in your milk. However, if you happen to be lactose intolerant yourself, no worries, there’s no evidence that the lactose in your breast milk will harm you or put your infant at any greater risk of becoming lactose intolerant.

Is There an Infant Formula for Lactose Intolerance?

Fortunately, if your kid is diagnosed as lactose intolerant, that doesn’t mean their nutritional needs can’t be met. There are non-dairy formulas out there made from soy, as well as hypoallergenic ingredients. Plus, there’s a whole slew of traditional dairy products, like milk, yogurt, and cheese, without lactose on the market—sometimes, it seems, more and more each day. They rely on other forms of milk, such as those made from soy, rice, and almonds. Other nutrients present in milk, such as calcium, can be found in a range of other foods. These include green leafy vegetables, like broccoli, spinach, and kale, as well as some nuts, beans, fish, and calcium-fortified fruit juices. Of course, if you’re ever concerned that your child isn’t getting enough nutrition, speak to your pediatrician or a pediatric nutritionist.

Next: As we mentioned, lactose intolerance symptoms often include uncomfortable gassiness. And, while there are an ever-increasing number of products out there that claim to relieve excess bubbles safely and naturally, they’re not all created equal. Learn more about the debate on giving your kid gas drops vs. gripe water to discover the science behind them. (Ahem, we’re sure you can guess on which side we at Mylicon stand.)


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