SOS Allergo · I understand & manage
The atopic march
From the skin to food and respiratory allergies
In some children, allergic conditions appear successively during the first years of life: eczema, food allergy and sometimes asthma or allergic rhinitis. This pattern was long called the ‘atopic march’. We now know that there are several atopic trajectories: this progression is neither inevitable nor the same for every child.
In this sheet
Three essential points
The atopic march is not inevitable
An infant with eczema will not necessarily develop food allergy and then asthma. There are many different trajectories.
Eczematous skin may promote food sensitisation
When the skin barrier is impaired, food proteins in the environment may come into contact with the immune system more easily.
The digestive route promotes tolerance
Introducing foods by mouth at the right time and in an age-appropriate form helps the intestinal immune system learn to tolerate them.
The classic atopic march
- Infant
- Atopic dermatitis / eczema.
- Infant – young child
- Food allergy in some children.
- Child
- Wheezing / asthma in some profiles.
- Older child – teenager
- Allergic rhinitis / rhinoconjunctivitis.
| Age | Possible manifestation |
|---|---|
| Infant | Atopic dermatitis / eczema. |
| Infant – young child | Food allergy in some children. |
| Child | Wheezing / asthma in some profiles. |
| Older child – teenager | Allergic rhinitis / rhinoconjunctivitis. |
What is atopy?
Atopy is a predisposition to produce IgE antibodies against common allergens. It may present as atopic dermatitis, food allergy, asthma, allergic rhinitis or rhinoconjunctivitis.
Why is eczema important?
Early, moderate-to-severe and persistent atopic dermatitis increases the later risk of sensitisation and food allergy, followed by respiratory symptoms in some children.
Skin, sensitisation and oral tolerance
Inflamed skin may promote sensitisation
When the skin barrier is impaired and inflamed, food proteins in household dust or on hands may come into contact with the immune system through the skin. Sensitisation may therefore develop before the child has even eaten the food.
The digestive route promotes tolerance
The intestinal immune system generally learns to tolerate foods that are eaten. Regulatory T cells contribute to this tolerance. Exposure by mouth tends to promote tolerance, whereas repeated exposure through inflamed skin may increase the risk of sensitisation.
What the PACI study teaches us
The PACI study found that early intensified eczema treatment reduced egg allergy at 28 weeks. However, this intensive protocol caused adverse effects and must not be reproduced without a dermatological indication.
Why recommendations have changed
Delaying the introduction of allergenic foods has not shown a protective effect and may miss a favourable period. Once complementary feeding has begun and the child is developmentally ready, allergens should not be deliberately delayed.
Early introduction: what studies show
- LEAP — peanut
- 640 high-risk infants. Among those with a negative initial skin prick test, 13.7% in the avoidance group were allergic at age 5, compared with 1.9% in the regular-consumption group.
- PETIT — egg
- In infants with eczema, active eczema control and gradual introduction of well-cooked egg from 6 months reduced egg allergy at 12 months: 8% versus 38%.
| Study | Main result |
|---|---|
| LEAP — peanut | 640 high-risk infants. Among those with a negative initial skin prick test, 13.7% in the avoidance group were allergic at age 5, compared with 1.9% in the regular-consumption group. |
| PETIT — egg | In infants with eczema, active eczema control and gradual introduction of well-cooked egg from 6 months reduced egg allergy at 12 months: 8% versus 38%. |
- Peanut
- A benefit from early introduction has been demonstrated, especially in high-risk infants.
- Egg
- Introduce well-cooked egg during complementary feeding.
- Other allergens
- Do not deliberately delay them; evidence for prevention is less robust.
| Food | Guidance |
|---|---|
| Peanut | A benefit from early introduction has been demonstrated, especially in high-risk infants. |
| Egg | Introduce well-cooked egg during complementary feeding. |
| Other allergens | Do not deliberately delay them; evidence for prevention is less robust. |
What should be done according to eczema severity?
- Mild, well-controlled eczema
- Usual complementary feeding without delaying allergens.
- Moderate-to-severe eczema or an already known allergy
- Discuss it promptly with the paediatrician or allergist so the introduction window is not missed while making the first exposure safe.
| Situation | Approach |
|---|---|
| Mild, well-controlled eczema | Usual complementary feeding without delaying allergens. |
| Moderate-to-severe eczema or an already known allergy | Discuss it promptly with the paediatrician or allergist so the introduction window is not missed while making the first exposure safe. |
Sensitisation does not mean allergy
A positive skin prick test or food-specific IgE result for a food that has never been eaten does not automatically mean clinical allergy. Broad testing may lead to unnecessary avoidance. A supervised oral food challenge may sometimes be needed.
What is the link with asthma and rhinitis?
Early and persistent atopic dermatitis with sensitisation increases the later risk of asthma or rhinitis. Eczema does not ‘turn into’ asthma: these conditions share an atopic susceptibility.
What parents can do
- Treat eczema correctly and follow the prescribed plan.
- Do not delay complementary feeding or allergen introduction.
- Offer peanut in an age-appropriate form and well-cooked egg.
- Continue foods that are tolerated and avoid systematic preventive exclusions.
- For severe eczema or known allergy, seek advice early rather than postponing introduction.
Avoid unnecessary elimination and preserve tolerance
In one cohort, 19% of children placed on an avoidance diet had a new immediate reaction on subsequent exposure; 30% of these new reactions were anaphylaxis. This does not mean every avoidance diet causes allergy, but it illustrates the risk of unjustified exclusion.
Once introduced and tolerated, a food should continue to be offered regularly. Tasting it once may not be enough. The optimal frequency is not known for every food.
Common misconceptions
- ‘A baby with eczema will inevitably become allergic.’
- False. There are many different trajectories.
- ‘It is better to wait before introducing peanut and egg.’
- False. Early introduction may be beneficial.
- ‘A positive IgE test means the food must be stopped.’
- No. Sensitisation does not mean clinical allergy.
- ‘The more foods we avoid, the fewer allergies there will be.’
- False. Unnecessary avoidance carries nutritional risks and a risk of losing tolerance.
| Misconception | Answer |
|---|---|
| ‘A baby with eczema will inevitably become allergic.’ | False. There are many different trajectories. |
| ‘It is better to wait before introducing peanut and egg.’ | False. Early introduction may be beneficial. |
| ‘A positive IgE test means the food must be stopped.’ | No. Sensitisation does not mean clinical allergy. |
| ‘The more foods we avoid, the fewer allergies there will be.’ | False. Unnecessary avoidance carries nutritional risks and a risk of losing tolerance. |
Questions to ask before changing the diet
- Has the food already been eaten several times without a reaction?
- Was the test requested after a suspected reaction or only ‘to check’?
- Was avoidance decided with a healthcare professional?
- Should the allergy be confirmed by an oral food challenge before prolonged avoidance?
Key points
The atopic march is not a predetermined destiny. Treating eczema correctly, introducing foods by mouth at the right time and not removing tolerated foods are essential principles.
Download the validated sheet (PDF in French)
Find all the guidance in the validated French patient document.
You may also want to read
Main references
- Halken S, et al. EAACI guideline: Preventing the development of food allergy in infants and young children. Pediatr Allergy Immunol. 2021.
- Santos AF, et al. EAACI guidelines on the management of IgE-mediated food allergy. Allergy. 2025.
- Du Toit G, et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy (LEAP). N Engl J Med. 2015.
- Natsume O, et al. Two-step egg introduction for prevention of egg allergy in high-risk infants with eczema (PETIT). Lancet. 2017.
- Yamamoto-Hanada K, et al. Enhanced early skin treatment for atopic dermatitis and food allergy prevention (PACI). J Allergy Clin Immunol. 2023.
- Yamamoto-Hanada K, Ohya Y. Atopic march and prevention of food allergy. 2024.
- Miranda-Waldetario M, Curotto de Lafaille MA. Skin sensitization and oral tolerance in food allergy. 2024.
- Chang A, et al. Natural history of food-triggered atopic dermatitis and development of immediate reactions in children. J Allergy Clin Immunol Pract. 2016.
General information: This sheet provides general guidance. It does not replace a consultation, diagnosis or personalised plan.
Scientific review: September 2026 · sosallergo.fr