Nut allergies: Recognising when a persistent cough signals danger

Early warning signs vary by age

Nut allergy reactions don't always begin with obvious breathing difficulties. Initial symptoms frequently involve the skin, mouth or digestive system, and presentations differ between children and adults.

Dr Ganesh notes that reactions vary considerably between individuals, with symptoms ranging from mild to severe. Early indicators include itching or tingling in the mouth, swelling of lips, face or tongue, hives, skin redness, or digestive complaints such as nausea, vomiting or abdominal discomfort. Some people develop coughing, wheezing or breathing difficulties. In young children, signs may be less obvious, with parents noticing sudden irritability, unusual tiredness, behavioural changes or feeding difficulties.

Any symptoms occurring shortly after eating or exposure to nuts warrant serious attention, particularly when multiple body systems are affected, Dr Ganesh advises.

Young children who cannot articulate their discomfort may rub their tongues, scratch their ears or become unusually irritable, Dr Kaur explains. Adults more commonly describe light-headedness, dizziness, chest tightness, wheezing or fainting.

A child coughing persistently after a biscuit. An adult developing hives following a restaurant meal. Swollen lips appearing after nuts that never caused trouble before. These subtle signs can mark the beginning of a severe allergic reaction, and families often have just minutes to act.

Dubai-based mother R. Pavithra recalls the moment her six-year-old son grabbed a handful of nuts at a gathering. He appeared fine initially, playing with friends for about 15 minutes. Then the coughing started. It grew more persistent, and he complained of pain despite drinking water repeatedly. Recognising the escalating danger, Pavithra rushed him to hospital immediately. He required overnight observation, and the family has remained vigilant ever since.

Nut allergies represent an immune system reaction to proteins found in peanuts or tree nuts, triggering symptoms that range from mild itching to life-threatening anaphylaxis. Globally, food allergies affect approximately 4.3 per cent of the population, though rates vary significantly by region, from 7.6 per cent in the United States to 0.61 per cent in Brazil. In the UAE, research indicates that 8 per cent of children experience food allergies, with family history playing a significant role. A study from Ajman found seafood and nuts among the most common triggers for university students in the Emirates.

Dr Rajashree Ganesh, Specialist Internal Medicine at Medcare Shaikh Saqr Al Qasimi Hospital, Dr Jaspreet Kaur, Specialist Internal Medicine at RAK Hospital, and Dr Mufaza, who works in a UAE school setting, explain how to identify early warning signs, understand when reactions become dangerous, and protect vulnerable family members.

Internationally, allergen patterns vary considerably. In North America and Northern Europe, peanut and egg allergies predominate, whilst in Asia, shellfish and fish allergies are more common. In the Middle East, a Saudi Arabian study found self-reported food allergies at 19.7 per cent, with eggs, shellfish, fish and peanuts identified as primary triggers.

Recognising anaphylaxis

The critical distinction lies in whether a reaction begins affecting the respiratory or cardiovascular system. Symptoms can emerge anywhere from minutes to two hours following exposure, and during that window, a reaction can become life-threatening.

Dr Kaur explains that when initial symptoms such as hives, flushing or swollen lips progress to involve the respiratory or cardiovascular system, including bronchospasm, wheezing, reduced blood pressure or dizziness, the situation demands immediate action.

Anaphylaxis, a severe and potentially fatal allergic reaction, can develop rapidly and doesn't require every possible symptom to manifest. Warning signs include difficulty breathing, wheezing, throat or tongue swelling, dizziness, fainting, or sudden blood pressure drops.

Once anaphylaxis is suspected, it must be treated as a medical emergency. Adrenaline should be administered immediately according to the person's allergy action plan, followed by urgent medical assistance. While fatal food-induced anaphylaxis remains rare globally, with an estimated incidence of 0.03 to 0.3 deaths per million people annually, most fatal cases occur during the second and third decades of life. In the UK and Canada, peanuts and tree nuts are leading causes of fatal food-induced anaphylaxis, with delayed epinephrine use and asthma presence identified as key risk factors.

Dr Mufaza describes anaphylaxis as a systemic reaction capable of causing severe airway swelling, bronchospasm and cardiovascular collapse, potentially progressing to cardiac arrest in extreme cases. This urgency underscores why preparation is essential.

Emergency response protocol

For anyone with a known severe allergy and a prescribed adrenaline auto-injector, maintaining a clear action plan is essential. Dr Kaur emphasises that suspected anaphylaxis requires immediate intervention.

Epinephrine (adrenaline) represents the single most effective treatment for severe allergic reactions and anaphylaxis, working within minutes to reverse life-threatening airway swelling, bronchospasm and cardiovascular collapse. Following epinephrine administration, emergency services must be contacted immediately.

Severe signs including airway or breathing compromise such as wheezing, shortness of breath, dizziness, light-headedness, loss of consciousness, or severe swelling of tongue, lips or throat require immediate epinephrine injection, Dr Kaur stresses.

Whilst antihistamines may help mild symptoms, they do not treat anaphylaxis. Adrenaline via auto-injector remains first-line treatment, Dr Mufaza notes. Anyone prescribed an auto-injector should understand its use, carry it consistently, and ensure family members and teachers can administer it. Trainer devices allow everyone to practise in advance.

Globally, epinephrine auto-injectors are available in only 60 per cent of countries, primarily high-income nations, with significantly limited availability in low- and middle-income countries. UAE residents benefit from access to these life-saving devices, a privilege not universally shared.

Sudden onset in adults

Eating nuts safely for years offers no guarantee against developing an allergy later. The immune system can change over time, with allergies appearing at different life stages, Dr Ganesh explains.

Allergy development requires two steps: sensitisation, where the immune system misidentifies a nut protein as a pathogen and produces specific IgE antibodies, followed by clinical reactivity, when subsequent exposure triggers IgE-mediated mast cell degranulation. Cross-reactivity represents the most common pathway, Dr Kaur notes.

Individuals with conditions such as eczema or asthma, or personal or family allergy history, face higher risk. In adults, factors including alcohol consumption, strenuous exercise, NSAID use and acute illness can increase reaction likelihood or severity. In developed countries, food allergy affects approximately 8 per cent of children and 10 per cent of adults, with prevalence rising mainly due to environmental factors combined with genetic susceptibility.

No simple method exists to predict who will develop a nut allergy. Genetic factors and immune system changes may contribute, though exact reasons remain unclear, Dr Mufaza says.

Peanuts versus tree nuts

Many assume peanut and tree-nut allergies are interchangeable, but this represents a misconception. Peanuts are legumes, whilst tree nuts include almonds, cashews, walnuts, pistachios and hazelnuts.

Peanuts and tree nuts are biologically distinct, Dr Mufaza explains. A person can be allergic to peanuts, tree nuts, or both. Allergy to one doesn't automatically mean allergy to all others.

This doesn't justify experimentation, however. Cross-reactivity between certain nuts can occur, and cross-contact risk exists during processing and preparation. People with confirmed nut allergies should undergo individual assessment with an allergy specialist rather than independently deciding which nuts are safe.

A 2019 study in the Annals of Allergy, Asthma & Immunology surveying 258 peanut-allergic patients found most could tolerate tree nuts, yet nearly 40 per cent avoided all nuts anyway, largely from cross-contact fears rather than confirmed allergies. Specialist assessment proves more reliable than guesswork.

Cross-contact risks

Even trace amounts of nut protein can trigger reactions. Small quantities transferred during food preparation through shared knives, cutting boards or countertops suffice to cause reactions in significantly allergic individuals.

Thorough equipment cleaning before use for someone with allergies is essential. Cooking doesn't eliminate the problem. Dr Kaur emphasises that cooking or heating food does not destroy nut allergens. High heat denatures some proteins, but nut allergens remain structurally intact and fully capable of triggering anaphylaxis.

She advises washing utensils and dishes in hot, soapy water or running them through a dishwasher, and washing hands with soap and water rather than relying on sanitiser, which doesn't remove proteins.

Labels deserve careful attention every time, Dr Ganesh adds, since ingredients can change between purchases. UAE food labelling regulations require nine major allergens—crustaceans, peanuts, soy, tree nuts, sesame seeds, fish, egg, milk and gluten—to be declared on packaged food labels regardless of concentration. A "may contain" warning should factor into every allergy sufferer's personal risk assessment.

School and social safety

Avoiding exposure is a shared responsibility. Parents must ensure schools or nurseries are fully informed about their child's allergy, symptoms to watch for, and required emergency actions, doctors explain.

Dr Kaur recommends a written Anaphylaxis Emergency Action Plan signed by the child's physician, alongside at least two unexpired, prescribed auto-injectors in original labelled boxes, with trained staff who can recognise and respond. Children should be taught not to share or accept food without checking with an adult. Dr Kaur suggests sending a nut-free treat from home resembling what other children eat, preventing the child from feeling excluded.

Dr Mufaza describes this in practice: their school environment is nut-free, with close attention paid to preventing food sharing and checking food brought for school events, particularly when external catering is involved.

The same applies beyond classrooms. Restaurants and hosts should be informed in advance, not assumed safe.

Can children outgrow nut allergies?

Some children do outgrow food allergies, but nut allergies prove more persistent than milk or egg allergies. Dr Ganesh notes that whilst some children may outgrow certain food allergies, nut allergies often persist longer than other childhood food allergies. Dr Kaur estimates roughly 15 to 20 per cent of children with peanut allergy eventually outgrow it. Adults can also develop new nut allergies later in life.

A 2024 study from the Murdoch Children's Research Institute published in Allergy followed 156 Melbourne infants with confirmed peanut allergy through to age ten. Two-thirds remained allergic by that point, and among those who did outgrow it, most had done so by age six. Rather than a single test at one point, the way certain antibody levels shifted over years best predicted who would outgrow the allergy and who wouldn't.

Whether an allergy has genuinely resolved cannot be assumed simply because someone hasn't reacted recently. Doctors rely on clinical history, skin-prick testing, IgE blood tests, storage-protein testing, and in selected cases, an oral food challenge under medical supervision. Families should not attempt such challenges at home because reactions can be unpredictable, Dr Ganesh warns, a caution Dr Mufaza firmly echoes.

For those who remain allergic, allergen immunotherapy offers carefully controlled exposure to reduce sensitivity over time, but it requires specialist supervision, can itself provoke reactions, and doesn't guarantee a cure.