As part of the allergic march (see here), children with food allergies are at a greater risk of developing asthma. Asthma is a condition that affects the airways, the tubes that carry air in and out of the lungs. When a person with asthma comes into contact with something that irritates their airways, this is called an asthma trigger.
When the airways become irritated, the muscles around the walls of the airways tighten so that the airways become narrower and the lining of the airways becomes swollen. Sometimes sticky mucus or phlegm builds up, which can further narrow the airways. The most common asthma trigger is an infection – simple coughs and colds – while others include cold air, exercise and tobacco smoke.
Asthma is a common problem for children with food allergy as they grow up, with 80 per cent of children with egg allergy going on to develop asthma and 70–75 per cent of those with nut allergy (see Allergy management in the Resources section here). It is extremely important that if your child develops asthma, the symptoms are spotted early and the management is optimal. This is because there is a link between asthma and the severity of food allergic reactions. If your child’s asthma is poorly controlled, he has a greater risk of having a more severe, life-threatening reaction to his allergenic food. The link is also found the other way in that food allergies can trigger life-threatening asthma attacks. Either way, it is vitally important that both your child’s food allergies and asthma are well controlled in order to minimise the severity of either.
Children with milk allergy are 10 times more likely to have a severe allergic reaction if they also have asthma, than those without asthma. Although death from food allergy is very rare, a high proportion of such fatal reactions occur in people with poorly controlled asthma because the breathing system is already suffering from the asthma and an anaphylactic reaction puts further strain on the breathing (see Resources section). Understanding why an allergic reaction may be mild on one occasion but devastating on another remains poor. However, there are certain risk factors for more severe reactions, the most important of which is the presence of asthma. Almost all fatal cases of anaphylaxis occur in asthmatics.
Early detection of the development of asthma is important. Therefore, your child needs to have regular reviews with his doctor who will be watching for the symptoms. If you suspect your child has any of the symptoms of asthma, always err on the side of caution. Discuss with your GP at the slightest concern about your child’s breathing to get an early diagnosis and inhaler prescription to begin managing his symptoms.
Our GP was brilliant. Zach had a few nights of non-stop coughing and a bit of coughing in the day when he ran around. I took him to the GP who prescribed a salbutamol inhaler with spacer device to be used four times a day. We opted for the facemask rather than mouthpiece. Zach uses it well and his coughing is much better, allowing him to sleep.
If you have any concerns that your child’s symptoms are not improving, revisit your GP until you feel that they are well controlled. Steroid inhalers, which prevent asthma attacks, can be prescribed as well as tablets for children with more severe asthma. It may be better to risk a degree of over-treating your child, than allow symptoms of poorly controlled asthma to go undetected or be poorly managed, as the risks to health are too great in the context of the food allergy.
With good asthma control your child will be free from symptoms. In a child too young to complain of symptoms, poor control can show itself by the presence of a night-time cough, wheezing or cough following known triggers (cold, exercise, allergens) and repeated hospital admissions. Peak flow monitoring where your child blows into a device that measures his breath, can be introduced at about five years old, depending on the child. Even if technique is initially poor, it may be beneficial to introduce the practice early on to encourage compliance later on.
If your child’s asthma is not well controlled, and he needs to be given the reliever inhaler (usually blue) regularly (more than 3–4 times a week), then discuss this with your doctor. In the UK, there is a standard guideline for escalating asthma treatment using different preventer inhalers (which contain steroids) or other medicines. The vast majority of asthma can be well controlled as long as medicines are taken regularly and correctly. If things are not going well, your practice nurse or doctor will need to check you are using the inhalers correctly and to ensure that your child is taking them regularly. They should also ask about symptoms of rhinitis (see Chapter 10) as this is an important cause of poor asthma control and is why many asthma attacks occur in the pollen season. Remember that when symptoms improve with regular asthma medicines, you need to keep taking them. Asthma is still a major killer in the UK and must be taken seriously.
If your child is diagnosed with asthma, the emergency plan for an allergic reaction must be changed to include giving their inhalers (see here and see here). Up to 10 puffs of the reliever should be given via a spacer device to try to prevent the allergic reaction changing from a mild to a severe one involving the breathing system. Any child with food allergy and asthma should also be prescribed and trained how to use adrenaline autoinjectors (here). If your asthmatic child has an allergic reaction, it is often worth considering giving a single dose of oral steroid medicine to stop the asthma flaring up a few hours later. This should be on your emergency treatment plan.
Most children with mild, intermittent asthma will outgrow their asthma completely or have mild asthma in adulthood. More severe childhood asthma or atopic symptoms increase the risk of asthma persisting or returning in adulthood. In addition to this, exposing your child to passive cigarette smoke or smoking decreases the likelihood of outgrowing asthma. Early intervention with anti-inflammatory therapy, such as appropriate use of oral corticosteroids, may prevent the progression of the disease and result in improved lung performance in later life.