Dairy Allergy vs Lactose Intolerance: Are They the Same?

 by Dr. Steve Hruby, D.C.
Reviewed by Dr. Steve Hruby, D.C.

SuperHumans are the toughest, fittest, healthiest and happiest human beings on this planet. My mission is to help you realize your superhuman potential and learn how to live a long, happy and healthy life.

  Fact Checked
 by Rhealyn Tropia, RMT
Reviewed by Rhealyn Tropia, RMT

I’m a content organizer, fact-checker and super mom who ensures content is medically-reviewed, highly accurate, and engaging. My passion is organizing information and ensuring the facts are presented in a manner that is interesting and easy to understand.

dairy allergy vs lactose intolerance

It can be challenging or unsafe to absorb cow’s milk if you have lactose intolerance or a dairy allergy. Although they are far from interchangeable, dairy allergy vs lactose intolerance are frequently confused. Both conditions require caution when consuming dairy products; their causes, effects, and treatments vary.

So, is dairy intolerance the same as lactose intolerance? No. A dairy or milk allergy is distinct from lactose intolerance. 

The inability of the body to adequately break down milk sugars is known as lactose intolerance. This may result in unpleasant stomach symptoms. This differs from dairy allergies, brought on by an immunological reactivity to the proteins in dairy foods, and can result in life-threatening reactions.

Lactose Intolerance

A person with lactose intolerance cannot digest milk sugars; therefore, they are not allergic to them. Lactose malabsorption describes the small intestine’s poor lactase production, which causes lactose intolerance. 

The inability to metabolize or assimilate lactose due to inadequate lactase levels causes stomach discomfort. Lactose intolerance symptoms typically appear a few hours after consuming lactose-containing food or beverage.

They may include:

  • Diarrhea
  • Feeling sick
  • Farting or gas
  • A bloated stomach
  • Stomach rumbling
  • Stomach cramps and pains

The quantity of lactose you’ve consumed determines the intensity of your reactions and when they start. So, can lactose intolerance get worse? Lactose intolerance frequently worsens with age, as your body is deprived of the capacity to generate lactase. Nonetheless, the intensity of symptoms usually is proportional to the amount of lactose consumed.

Possible causes of lactose intolerance include:

  • Lactase non-persistence: After childhood, the intestine may generate decreased lactase.
  • Congenital lactase deficiency: A person with this uncommon syndrome is born with minimal or no lactase production.
  • Injury: An individual may generate less lactase if they have small intestinal damage, such as that brought on by Crohn’s or celiac disease.
  • Premature birth: Early lactase production in the small intestine is sometimes insufficient in premature babies. However, the production increases as the infant reach maturity.

Dairy Allergy

When someone consumes dairy products, they may develop a milk allergy, an immunological condition. The most typical food allergy in newborns and young youngsters is an allergy to cow’s milk. Other forms of milk, like those from sheep, goats, and buffalo, might cause allergic reactions in certain people.

cow and milk bottle on a light blue background

When someone with a dairy allergy comes in contact with dairy-containing items, their immune system overreacts. Dairy allergies can be either immunoglobulin E (IgE)- or non-IgE-mediated.


When the immune system recognizes a foreign substance, it may produce a specific antibody known as IgE. When the immune system labels dairy proteins as dangerous, it reacts by producing substances like histamine.

This chemical release brings on the signs of an allergic reaction. Usually, an IgE-mediated reaction happens right away.

Symptoms that appear include:

  • Vomiting
  • Anaphylaxis
  • Shortness of breath
  • Coughing or wheezing
  • Swelling, itching, or hives

Dairy allergies that develop quickly are taken seriously since they can result in anaphylactic shock.


Other immune system cells are involved in a non-IgE-mediated reaction instead of IgE. The reactions typically result in gastrointestinal symptoms such as nausea, bloating, and diarrhea but do not manifest as fast as IgE-mediated attacks.

This is frequently why many individuals mistake lactose intolerance for a non-IgE-mediated dairy allergy.

Lactose Intolerance vs. Dairy Allergy

Dairy allergies and lactose intolerance vary because the former is an allergy while the latter is an intolerance. Dairy allergy results from an immunological response, whereas a deficiency of lactase enzyme brings about lactose intolerance. 

Let’s further explore the difference between milk allergy and lactose intolerance in the table below: 

 Lactose IntoleranceDairy Allergy
DevelopmentThough it can start at birth, it tends to manifest in adulthood.Typically occurs from infancy, although some people outgrow their allergy.
SymptomsNausea, abdominal pain, diarrhea, flatulence, constipation, borborygmus, rumbling in the stomach, and bloating are examples of digestive symptoms. Non-digestive symptoms include headache, dizziness, memory lapses, lack of focus, muscle and joint discomfort, mouth ulcers, fatigue, and sluggishness.Some of the most typical ones include nausea, abdominal pain, diarrhea, rashes, wheezing, irritation around the mouth, lip, throat, or tongue swelling, breathlessness, vomiting, or even anaphylaxis.
OnsetIn most cases, symptoms develop gradually.Regarding IgE-mediated allergies, symptoms manifest within two hours of ingesting the food, although non-IgE allergies may take longer than that to manifest.
EffectSymptoms rarely pose a life-threatening danger, although they can be very uncomfortable.In contrast to the severe, sometimes fatal reactions caused by IgE allergies, which can include anaphylaxis, non-IgE diary allergy incidents are seldom fatal (anaphylactic shock).
QuantityA person might consume minimal dairy without experiencing any negative effects.An allergic reaction will occur even with small doses of the allergen.
ExposureOnly if the individual consumes dairy products will there be a reaction.A reaction happens if someone ingests dairy or a food or beverage item from a location where dairy is present.
Risk FactorsOnly a small percentage of people can stay digesting lactose throughout their lives, and most individuals typically stop making lactase as they age.Cow’s milk allergy eventually goes away by age six or seven. 


Several digestive and non-digestive symptoms can be caused by both lactose intolerance and cow’s milk allergy. The bacterial fermentation of unprocessed lactose inside the colon mainly causes gastrointestinal problems within at least 30 mins to 2 hours after consumption in lactose intolerant individuals. 

out of order text on a persons tummy

Contrarily, the signs and symptoms of a cow’s milk allergy differ depending on if they are IgE or non-IgE mediated:

  • Non-IgE-mediated symptoms: Slow-onset symptoms usually affect the skin and digestive system and are delayed responses.
  • IgE-mediated symptoms: Also known as rapid-onset symptoms, these symptoms appear minutes after consumption and typically include cutaneous, respiratory, and, in extreme cases, anaphylactic reactions.

Shared Symptoms

Most likely because they both have similar symptoms, individuals frequently confuse them. Some of the shared symptoms include: 

  • Nausea
  • Diarrhea
  • Abdominal pain

Dairy Allergy Symptoms

While you could also be allergic to soy or other types of milk, milk allergies typically only apply to cow’s milk. Although milk allergy most frequently affects infants and young children, it can happen to anyone at any age. 

Over two percent of children below the age of three have a milk allergy, the most prevalent food allergy among children. By age five, many kids no longer experience milk allergies.

The allergic reaction to milk can start right away or take many hours to manifest. Some signs could be:

  • Nausea
  • Diarrhea
  • Skin rash
  • Stomach pain
  • Trouble breathing
  • Swelling of the lips or throat

Lactose Intolerance Symptoms

Lactose intolerance can be inherited or result from bacterial or viral infections that harm the small intestine. After consuming milk or another dairy product, you’ll generally experience lactose intolerance symptoms within 30 minutes and 2 hours. Some signs could be:

  • Nausea
  • Diarrhea
  • Stomach pain
  • Gas and bloating


Lactose intolerance and cow’s milk allergy are distinct disorders requiring different diagnostic procedures including an at-home lactose intolerance test. Some of the diagnosis methods used are as follows:

doctor holding a pen and form
  • Intestinal biopsy: The level of the lactase enzyme within the intestine is measured using an intestinal biopsy.
  • Genetic test: Genetic changes linked to lactase persistence and non-persistence can be found by genetic testing.
  • Lactose tolerance test: This blood test gauges how much blood sugar rises after taking lactose. Blood sugar levels failing to increase over 1.1–1.4 mmol/L indicates that the body did not correctly absorb and digest lactose.
  • Lactose breath test (LBT): It assesses the amount of hydrogen in the exhaled air following a lactose load at dosages varying from 20 to 50 grams given after 8 to 12 hours of fasting. Positive hydrogen concentrations are defined as those exceeding 20 parts per million (ppm).

The primary diagnostic tests for cow’s milk allergy include: 

  • Specific serum IgE: This test estimates the quantity of IgE in the blood likely to react to milk proteins.
  • Skin prick test: In this test, a lancet carrying an allergen drop is used to prick the patient’s skin. An allergist or immunologist is ideally suited to assess the outcomes.
  • Double-blind, placebo-controlled oral food challenge: It is done by a physician by giving out small amounts of the meal and then progressively raising the quantity until signs of a dairy allergy or hypersensitivity emerge.

Risk Factors

Certain risk factors may increase the likelihood of acquiring lactose intolerance or dairy allergy.

Risk factors for lactose intolerance

Ethnicity may affect the geographical prevalence and age when lactase production declines. According to data on the prevalence and incidence of lactose intolerance worldwide, it may occur in the following ways:

  • Nearly half of Asians, Africans, and South Americans.
  • Up to one hundred percent of individuals in Asian nations.
  • Symptoms may start between two to three years in Hispanic, Asian, or African children.
  • The first symptoms may appear in youngsters of European and American ancestry as early as age five or adolescence.

On the other hand, individuals in northern Europe have a greater prevalence of the lactase-persistence trait.

Risk Factors for Cow’s Milk Allergy

Contrary to lactose intolerance, cow’s milk allergy frequently goes away by age six or seven. As a result, it primarily affects kids and is most likely to affect one to two percent of kids.

Nevertheless, research has found that for male kids with other allergies—like asthma, multiple food allergies, atopic dermatitis, and allergic rhinitis—the likelihood of having a cow’s milk allergy is double that of females.

Treatment and Management

Following are some possible methods for treating and controlling lactose intolerance:

  • Addressing a core disease in persons with secondary lactase insufficiency.
  • Dietary adjustment: To alleviate symptoms, restrict the lactose you consume or avoid it entirely. Start by exploring the fructose and lactose intolerance food list.
  • Supplementation with lactase: Lactase supplements that comprise the enzyme lactase and may help break down lactose may be recommended by doctors to people who are lactose intolerant. 

What You Should Know About Dairy Allergy and Lactose Intolerance FAQS  

pouring milk into a glass jar

Is Milk Allergy Worse Than Lactose Intolerance?

A milk allergy is a little more intense than lactose intolerance since allergic reactions might occur immediately or after many hours. Milk allergy is typically associated with cow’s milk. However, you could also be sensitive to other milk varieties, such as soy. Hence if you are wondering if you can be allergic to almond milk, the answer is yes.

What Can Be Mistaken for Lactose Intolerance?

Lactose intolerance symptoms are comparable to other digestive illnesses, such as inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS). It is easy for someone with IBS to wrongfully believe they suffer from lactose intolerance when they are not.

Can You Eat Cheese if You Have a Milk Allergy?

No. Milk allergies are caused by an allergic reaction to the proteins found in cow’s milk. Because milk-based cheese and yogurts are fermented milk products, ingesting any quantity of cheese may cause an allergic response.

Can You Be Allergic to Cow’s Milk but Not Lactose?

Yes. Although it can be difficult to tell the two apart, they are very different conditions. An immunological response to the protein in milk causes a food allergy, such as sensitivity to cow’s milk. The incapacity to dissolve lactose, the carbohydrate in milk, results in lactose intolerance.

Does Lactose-Free Mean Dairy Free?

No. Dairy-free foodstuffs do not have milk or dairy products, whereas lactose-free products could contain milk but not lactose. Lactose-free products are dairy products that have had lactose eliminated. 


Lactose intolerance and dairy allergy are two separate dairy-related disorders. Lactose intolerance is triggered by the failure of the body to digest lactose, but cow’s milk allergies are induced by an immunological response to the proteins contained in milk.

Though they overlap symptoms such as nausea, abdominal discomfort, and diarrhea, lactose intolerance and cow’s milk allergy have distinct body effects and require different therapy.

Milk substitutes can form a vital component of a balanced diet, particularly if you suffer from a dairy allergy. 

Try the Optima Healthy Gut Solution, a powdered supplement to improve the absorption of nutrients, aid in better elimination of waste, reduce gas and bloating, and much more. Get the supplement today and start your healthy journey! 

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