The triad of asthma, eczema, and allergies explained - Medical News Today

Eczema, asthma, and allergies sometimes occur together. Doctors call this the atopic triad. Eczema, common in babies and children, is a risk factor for later developing asthma and allergies.

All three conditions cause inflammation, which may help explain the link. Moreover, both eczema and allergies happen when the immune system secretes inflammatory chemicals.

In the case of allergies, the immune system overreacts to harmless substances, while eczema may cause a person's body to attack itself.

Doctors do not yet fully understand the atopic march, the tendency for eczema to develop into allergies and asthma. But the presence of one condition in the triad is a clear risk factor for another, which may help people with symptoms, their caregivers, and healthcare professionals anticipate symptoms and make treatment decisions.

In this article, we cover the link between eczema, asthma, and allergies and look at how to manage these conditions.

The atopic triad refers to the tendency of asthma, eczema, and allergies to occur together. The progression typically begins with eczema, followed by food allergies, and then the development of asthma and allergic rhinitis, which causes sneezing and a runny nose. Doctors also call this progression the atopic march.

Early research found that immunoglobulin E (IgE) plays a role in the triad. IgE is an antibody involved with the functions of the immune system, such as inflammation. While inflammation is important in these three conditions, we now know that IgE is not present in all cases of asthma, allergies, or eczema.

According to a 2018 paper, 20% of children with mild eczema develop asthma, while 60% with severe eczema develop asthma.

A 2021 study similarly linked eczema to the later development of peanut allergies, especially if the eczema is severe. The study included 321 babies. Peanut allergies developed in 18% of the babies with eczema, 19% with other food allergies, and 4% who had a relative with a peanut allergy. This suggests that eczema and other allergies better predict peanut allergies than genetics.

While people with one symptom in the triad are more likely to develop other symptoms, having one symptom does not guarantee the development of others. A 2014 cohort study of 9,801 children found that only about 7% of children with at least one symptom develop symptoms consistent with the atopic march.

Doctors do not fully understand the atopic march. Several underlying factors, such as genetic differences in immune response and inflammation, may help explain it.

Some evidence suggests that exposure to allergens through eczema-damaged skin may trigger immune system responses that lead to inflammation and allergies. Data from mice, for example, show that certain kinds of peanut exposure on the skin increase the risk of sensitivity to milk.

Environmental factors may also play a role. Children exposed to farm animals, for example, have a lower risk of atopic march, while antibiotics seem to increase the risk.

Because atopic march begins with eczema, doctors have focused on how eczema might influence the development of later symptoms. Some evidence suggests that early eczema treatment may help prevent subsequent allergies and asthma, perhaps by preventing exposure to allergens through a damaged skin barrier.

It is not possible to manage the three symptoms with a single treatment. Instead, treatment focuses on managing each symptom individually.

New research into biological therapies to treat these conditions is ongoing.

Eczema

Keeping the skin well-moisturized is critical for people with eczema since the skin's moisture barrier is damaged. This makes the skin dry out faster and more severely. Anti-inflammatory medication such as hydrocortisone can help. When itching is intense, a doctor may recommend antihistamines.

Identifying triggers can help reduce the frequency and severity of flares. This includes avoiding exposure to environmental allergens.

Learn more about treatment options for eczema here.

Allergies

Avoiding allergens is critical for people with severe, life threatening allergies that cause anaphylaxis. For milder allergies, such as seasonal respiratory allergies, remaining indoors, using an air filter, and limiting contact with allergens may help.

Depending on the allergen, a person may undergo immunotherapy, or allergy shots, which helps desensitize the body. People with severe, life threatening allergies may need to carry an EpiPen for emergencies.

Learn more about allergy treatments here.

Asthma

Treating asthma requires identifying and avoiding asthma triggers, which may include allergens. Some people have asthma attacks when they are stressed, so calming strategies like deep breathing and meditation can help.

During an asthma attack, a person may need to use an inhaler to take a corticosteroid. A person may need other medications for severe asthma. When an asthma attack does not relent, a person may need to go to the hospital.

Learn more about treatments for asthma here.

A different triad, Samter's triad, suggests that people with asthma are more likely to develop nasal polyps and aspirin intolerance. Researchers do not know why this happens, but nonallergic hypersensitivity reactions may be to blame.

Samter's triad involves inflammation like the atopic triad, but the inflammatory patterns are different. Samter's triad does not involve IgE.

Aspirin and some other anti-inflammatory drugs inhibit the expression of the enzyme cyclooxygenase-1. People with Samter's triad who take these drugs develop respiratory symptoms similar to an allergic reaction. Most also develop respiratory symptoms after drinking alcohol.

Although the triad of asthma, allergies, and eczema are distinct from Samter's triad, people with asthma have a higher risk of this triad. And because people with allergies and eczema have a higher risk of asthma, they may also have an elevated risk for Samter's triad.

A doctor can help with treating any of these conditions. People should speak with a doctor about symptoms of eczema, allergies, or asthma. It is especially important to seek help if symptoms are severe, such as if eczema cracks open and bleeds, allergies cause breathing difficulties, or asthma attacks are severe or frequent.

People undergoing treatment for these conditions should also contact a doctor if:

• their symptoms get worse, or they develop new symptoms
• they develop another condition, such as when a person with eczema develops allergies
• treatment does not work or causes unpleasant side effects

Asthma, allergies, and eczema all correlate with high levels of inflammation and disproportionate reactions to harmless substances. While most people who have one condition will not develop all three, they are much more likely to develop another triad disorder than those who do not have one.

Though these conditions tend to occur together, doctors cannot treat them as a single diagnosis. Instead, the presence of one component of the triad merely predicts that a person might develop another.

A knowledgeable doctor can help with properly diagnosing asthma, eczema, and allergies and appropriately treating them.