Part of the London Allergy Clinic
Diagnosis & Specialist Care of Allergy - Since 1982
Around half of all babies wheeze at some point in their first year of life.¹ Most will grow out of it without ever developing asthma. But for a significant number — particularly children with a family history of allergy or atopic conditions — recurring wheeze and breathing difficulties are the beginning of something more persistent. Knowing which group your child falls into, and why, is one of the most important things a specialist assessment can establish.
Not all wheeze is asthma
There are two distinct patterns of childhood wheeze:
The first and more common is wheeze triggered by viral infections — colds and respiratory bugs that temporarily narrow the airways. This pattern is especially common in babies and toddlers, tends to resolve between illnesses, and the majority of children who follow it will be symptom-free by the age of six.
The second is a wheeze or persistent cough that occurs between illnesses — at night, during exercise, or when exposed to allergens — is more likely to be associated with atopy, the underlying allergic tendency. Children in this group face a meaningfully higher risk of developing persistent asthma. Research suggests that nearly one-third of children with atopy will go on to develop asthma later in life.¹
The outlook is often better than parents fear. Studies suggest that between 30 and 70% of children diagnosed with asthma will see significant improvement or become symptom-free by early adulthood — though persistent wheeze during adolescence is more likely to continue.¹
The allergy-asthma connection
Atopy — the tendency to produce IgE antibodies in response to allergens — is considered the single most significant risk factor for childhood asthma.¹ Children who have eczema, hay fever or food allergy appear to be at higher risk of developing asthma,¹² and among the allergens involved, house dust mite is considered the most commonly identified cause of allergic asthma.³ Research indicates that up to 85% of children with bronchial asthma are sensitised to house dust mite species.⁴
House dust mites are found in most homes. Their main habitat is the bedroom — particularly mattresses and pillows. They thrive in humid conditions; maintaining indoor humidity between 30 and 50% is thought to make the environment less hospitable for them, though the evidence on whether environmental control measures meaningfully improve asthma outcomes is mixed.⁴
It is worth noting that sensitisation to a particular allergen — such as house dust mite — does not automatically predict how severe a child's asthma will be. The factors that lead to developing asthma and those that determine its severity appear to be partly distinct.³ This reinforces why individual assessment matters: a child's allergen profile is one part of a larger clinical picture.
Children with eczema, hay fever or food allergy appear to be at higher risk of developing asthma.¹² Understanding which allergens are relevant for your child can form a useful part of their management plan alongside appropriate medical treatment — though specialist guidance is important before making significant changes to a child's environment.
What to look out for
Asthma doesn't always look the way parents expect. A persistent dry cough — especially one that's worse at night, after exercise, or in cold air — can be the main or only sign.
Other symptoms include:
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A wheezing or whistling sound when breathing
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Shortness of breath, or a child who tires faster than usual during activity
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A sensation of chest tightness (older children may describe this)
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Symptoms that improve and then return
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A cough that lingers unusually long after a cold
If your child develops sudden, severe breathing difficulty, call 999 or go to A&E immediately. This page is about specialist assessment of ongoing or recurrent symptoms, not emergency care.
What we assess
Every assessment begins with a detailed clinical history. The pattern, triggers, frequency and treatment response of your child's symptoms — alongside family allergy history — is often more informative than any single test.
We then use a combination of approaches based on your child's age and clinical picture:
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Allergy testing — skin prick testing and/or specific IgE blood tests to identify allergenic triggers that may be driving or worsening symptoms;
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Review of current treatment and inhaler technique — the right medication works poorly if the inhaler is used incorrectly, and this is extremely common;
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Assessment of co-existing allergic conditions — eczema, hay fever and food allergy frequently occur alongside asthma; addressing them as part of the whole often improves asthma control
FeNO testing — a clearer picture in minutes
We are introducing fractional exhaled nitric oxide (FeNO) testing — a noninvasive and painless test in which a child simply breathes out slowly into a small device.
FeNO measures the level of nitric oxide in exhaled breath. This is a biomarker for eosinophilic airway inflammation — the type most closely associated with allergic asthma. Elevated readings can indicate that the airways are inflamed even when a child appears to be managing reasonably well day-to-day.
The test is particularly useful in two situations: when there is genuine uncertainty about whether a child has asthma, and when assessing whether current inhaler treatment is working as it should. It takes only a few minutes, requires no needles or medication, and is well tolerated by children.
The test can be performed during your initial consultation and the doctor can provide interpretation at the same time.
About Dr Tammy Rothenberg
Dr Tammy Rothenberg is a Consultant Paediatrician and Allergist and the Paediatric Asthma Lead at Homerton Healthcare NHS Foundation Trust, where she leads the diagnosis and management of childhood asthma and recurrent wheeze across one of East London's busiest paediatric services.
Tammy holds an MSc in Allergy from Imperial College London — giving her valuable dual expertise in both the allergic and respiratory dimensions of asthma.She is a member of the British Society for Allergy and Clinical Immunology (BSACI) and its Paediatric Allergy Group.
Dr Tammy Rothenberg
Consultant Paediatrician
Frequently Asked Questions
References
1. Lizzo JM, Goldin J, Cortes S. Pediatric Asthma. In: StatPearls [Internet]. StatPearls Publishing; updated May 2024. Available at: ncbi.nlm.nih.gov/books/NBK551631
2. NHS. Asthma. Last reviewed 7 April 2025. Available at: nhs.uk/conditions/asthma
3. Abstract PA5369. Dust mite sensitization and childhood asthma severity. European Respiratory Journal. 2023; 62(Suppl. 67). Available at: publications.ersnet.org/content/erj/62/suppl67/pa5369
4. Klain A, Senatore AA, Licari A, et al. The Prevention of House Dust Mite Allergies in Pediatric Asthma. Children (Basel). 2024;11(4):469. Available at: pmc.ncbi.nlm.nih.gov/articles/PMC11048898
If your child has a persistent cough, recurrent wheeze, or an asthma diagnosis that doesn't feel well controlled, specialist input can provide clarity and a practical plan.
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