Milk Allergy: Symptoms, Causes, Risk Factors, Diagnosis And Treatment

Milk allergy occurs when our body's immune system responds abnormally to one of the proteins present in milk and cause symptoms due to the allergic reaction. Cow's milk is the primary cause of milk allergy in young children. However, the allergy can also be from the milk of goats, sheep, buffalo or other mammals.

Milk contains two types of protein - casein and whey. The solid part of milk is known as casein which comprises almost 80% of milk protein while whey, the liquid part of milk, contains the remaining 20% of milk protein. Other food and food products like sausage, chewing gum, body-building drinks, meats, energy drinks and tuna may contain casein ^[1] .

According to the epidemiology of milk allergy, 65% of the total population worldwide are allergic to milk during their infancy but later, outgrows it before they reach the age 16. The allergic reaction starts usually when our immune system thinks that the proteins in milk are some harmful invaders and so, reacts to it quicky by releasing a chemical called histamine ^[2] . Other foods that may cause such reactions are eggs, peanuts, fish, soy and shellfish.

Symptoms Of Milk Allergy

Milk allergy differs from individual to individual. In some people, the symptoms last for a few minutes while in others, it may cause trouble for an hour or days. Common symptoms of milk allergy are as follows ^[3] :

• Wheezing
• Throat tightness
• Itching around the mouth
• Swelling on the lips ^[1]
• Vomiting
• Hives
• Shortness of breath
• Coughing
• Runny nose ^[3]
• Watery eyes
• Skin rashes
• Blood in the stools

Causes Of Milk Allergy

There are certain proteins present in milk which act as foreign material to the immune system. Milk allergy is a response of the body's immune system to such protein types found in milk. The symptoms of allergy occur immediately or later.

When the immune system malfunctions, some of the proteins found in milk are recognized as foreign material and harmful to the body. So, to neutralize them, the body triggers the release of an antibody called immunoglobin (IgE) ^[4] .

Next time, when the same person comes in contact with the milk protein, the IgE antibodies released prior, recognizes it and produces a range of chemicals like histamine which causes symptoms like sneezing, itching and runny nose.

According to medical experts, a child with a milk allergy is allergic to either one or both the proteins found in milk. If these proteins are added to some processed foods, they can also cause allergic reactions to a person.

Risk Factors Of Milk Allergy

The risk factors of milk allergy are as follows:

Family history: If there's a history of milk allergy in your family or your parents are allergic to milk, the chances are higher than the children too, may get affected by the same ^[5] .

Other allergies: If a person has some other kind of allergies like soy and almond allergy, there's an increased chance that they will be affected by milk.

Atopic dermatitis: If a person is suffering from the red and itchy skin called atopic dermatitis, they are likely to get food allergy ^[6] .

Age: Children are more likely to get milk allergy but as people age, the digestive system matures and so, children who are allergic to milk are less likely to react to it ^[7] .

Complications Of Milk Allergy

The complications of milk allergy include:

• Eczema ^[8]
• Allergic asthma ^[9]
• Sensitization to other types of allergens
• Hay fever ^[10]
• Growth and developmental problems in children
• Death due to anaphylaxis ^[11]

Diagnosis Of Milk Allergy

The diagnosis is carried out by the following processes.

• Medical history: Here, the doctor will perform a physical exam and ask details about the food which you eat daily.
• Blood test: The blood test will determine the amount of an antibody (IgE present in the blood ^[12] .
• Skin test: Here, a skin test is carried out to find out whether you are really allergic to milk protein or not. The process is done by pricking the skin and exposing it to a small amount of milk protein ^[13] .

If the above-mentioned tests fail, the doctor will suspect for some other kind of allergies rather than milk allergy.

Treatment Of Milk Allergy

The best treatment for milk allergy is avoiding milk and all milk-based products. People who have milk allergy should properly check the ingredients labelled in the product and then consume it.

Usually, doctors will advise the patient with a milk allergy to keep an adrenaline auto-injector for an extreme allergic reaction (anaphylactic shock). In case, when the child has a milk allergy, his/her teachers and caregivers should be aware of the condition. Carrying over-the-counter antihistamine is also a good idea for allergic people ^[14] .

Tips To Deal With Milk Allergy

• Check the ingredients section of the processed food for any signs of milk on the list ^[15] .
• Always carry your epinephrine auto-injectors ^[14] .
• Keep a diary to note down what foods you had in a day and any side effects from them.
• Don't miss out on medicines to keep your symptoms in control.
• Wear an alert bracelet so that others may come to know about your problem in case of an emergency.

Sources Of Milk That Should Be Avoided

• Yoghurt
• Buttermilk, low-fat milk and whole milk ^[16]
• Cheese or cheese-based products
• Butter, butter oil, ghee, butter flavouring and butterfat
• Cottage cheese, sour cream and pudding
• Candies, caramel, nougat and other chocolates

While buying any food product, it is hard for people to recognise milk in it as the ingredients do not contain the word 'milk' but other names of its form. The easiest ways to identify milk is by the following names:

• Casein, rennet casein, casein hydrolysate and other names which contain the word casein in it.
• Lactalbumin and lactoglobulin.
• Lactose and lactulose or words with prefix 'lact'.
• Whey or whey hydrolysates
• Artificial butter or cheese flavour