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What happens if my child has a peanut allergy?If your child has a peanut allergy, her immune system will react after she's eaten peanuts, because it wrongly sees this food as a threat.
Allergic reactions to peanuts are often mild, but can sometimes cause a severe reaction called anaphylaxis, which can be life-threatening (Anaphylaxis Campaign 2012). So it's understandable that parents worry if their child is diagnosed with a peanut allergy (Cummings et al 2010).
How common is peanut allergy?Between one per cent and two per cent of children in the UK are thought to be allergic to peanuts (Venter et al 2010), so it's uncommon. Most children will develop the allergy when they are about a year or two years old (Hourihane et al 2007).
A peanut allergy usually lasts for life, though up to 20 per cent of children outgrow the allergy (Burks 2008).
How do children develop peanut allergies?Allergies, tend to run in families. If your child has a sibling or parent with an allergic condition such as asthma, hayfever or eczema, she is more likely to develop an allergy to foods such as peanuts (Lack 2008). Children who have a peanut allergy often have eczema or asthma (or both) as well (Cummings et al 2010).
For your child to become allergic to peanuts, she must first come into contact with small traces of them. This process is called sensitisation.
If she has a tendency to allergies (atopic or atopy), this initial contact may alert her immune system so that she reacts the next time she comes into contact with peanuts. However, most peanut-allergic children have their first reaction the first time they eat peanuts.
Some experts think that children become sensitised to peanuts if peanuts come into contact with their skin (Strid et al 2005). If she has eczema (Lack 2008), your child has an increased risk of developing a peanut allergy. The more severe the eczema is, and the earlier it starts, the higher her risk of a peanut allergy (NICE 2011).
Some eczema creams used to contain peanut oil, also called arachis oil. In one study, when children with eczema had these creams rubbed on to inflamed skin, it increased their likelihood of developing a peanut allergy(Lack et al 2003). Zinc and castor oil ointment also contains arachis oil, though these tend to no longer be used. Check the ingredients list of any creams that you apply to your child's skin if you are worried.
Another theory is that babies with eczema living in a family where lots of peanut products are eaten are more likely to develop an allergy(Fox and Lack 2005, Fox et al 2008). Peanut butter sticks to fingers, and is easily transferred to your baby's skin by an affectionate sibling or friend.
What are the symptoms of a peanut allergy?If your child has a peanut allergy, the symptoms will probably be immediate, and may include:
- hives (nettle rash) around her mouth, nose and eyes, which may spread across her body
- mild swelling of her lips, eyes and face
- runny or blocked nose, sneezing and watery eyes
- itchy mouth and irritated throat
- nausea, vomiting and diarrhoea (NICE 2011: 25-26)
You should take your child to a doctor if you suspect that she has a peanut allergy. The doctor will refer you to an allergy clinic that specialises in children's allergies.
If your child has a more severe reaction, she may be wheezing, have breathing difficulties, throat and tongue swelling, and a sudden drop in blood pressure. This is known as anaphylaxis (RC 2008), or anaphylactic shock, and can be life-threatening.
Fortunately, severe reactions are rare(RC 2008). If you suspect your child is having a severe allergic reaction, use an adrenaline pen if you have been prescribed one, and call an ambulance immediately. Don't try to make your child vomit (RC 2008).
Can I prevent my baby from developing a peanut allergy?We don't know if anything can prevent your baby from developing a peanut allergy in the first place.
Even if you have a history of allergies in your family, there's no convincing evidence to suggest that eating peanuts when pregnant or breastfeeding increases your baby's risk of having a peanut allergy (Kramer and Kakuma 2012, NICE 2011: 23).
Breastfeeding exclusively for at least four months to six months may help to reduce your baby's risk of developing allergies (Snijdres et al 2007, Thyagarajan and Burks 2008), though the evidence is mixed (Matheson et al 2012). The Department of Health recommends that your baby has only breastmilk for the first six months of her life (DH 2003).
Taking probiotics during pregnancy and when you are breastfeeding, or adding probiotics to formula milk, may potentially reduce the risk of your baby developing allergies, but more research is needed (Osborn and Sinn 2007).
Some studies even suggest that eating peanuts during pregnancy may make your child less likely to develop a peanut allergy. Children from cultures who eat peanuts from an early age seem to be protected against the allergy (Fox et al 2009). However, we need more research before we can be sure of this (Maslova et al 2012).
So it's unclear if omitting peanuts from her diet or introducing them as a weaning food is the best way to prevent a peanut allergy (LEAP 2009).
How can I manage my child's peanut allergy?If your child is diagnosed with a peanut allergy, try not to worry. Your paediatrician, allergy specialist or dietitian will provide you with all the information and advice you need to manage it.
You should be given specific advice about understanding food labels and managing "may contain nuts" advice, as well as information about recognising and treating allergic reactions. You should be given a written emergency plan with appropriate emergency medications, which may include an adrenaline auto-injector, such as an Epipen or Jext.
Your doctor should also check your child for any sign of asthma, as well as provide follow-up appointments to find out if your child has outgrown her peanut allergy.
See Anaphylaxis Campaign factsheet and Allergy UK for more information, support and advice about allergies.
Last reviewed: January 2013
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