Allergy – The Genetic Risk

Today, in the second decade of the twenty-first century, a staggering 50% of UK children have been diagnosed with one or more allergic conditions.

These most commonly take the form of allergic diseases such as asthma, atopic eczema, hay fever or food allergies. Most people know someone who suffers from an allergy, and are familiar with some of the common symptoms that allergy sufferers may experience: a runny nose, sneezing, itchy eyes, skin rashes, digestive complaints and breathing problems.

However, there are many questions that allergy sufferers have about their conditions as they look to find ways to control symptoms. As research studies are undertaken, new facts and theories as to why people suffer from allergy, and the best course of action to control these symptoms, emerge.

With the rapid increase in childhood allergies parents are beginning to ask what can be done to prevent allergy in the first place, and how likely their children are to develop allergies in the future.

Doctors cannot predict with certainty which children will develop an allergy. However, it has been noticed that some families seem to include more individuals with allergies than other families. Children born into families where allergies already exist show a higher than average chance of developing allergies themselves. This increased tendency for families and individuals to develop allergies because of their genetic links is known as being atopic.

Researchers estimate that over half of children from atopic families will go on to develop an allergic disease, while the incidence of allergy in children from families that have no allergic history is only one in five. The risk of inherited atopy increases slightly further in families where both parents are allergy sufferers. This means that both parents can pass on the potential to develop allergy, although where the mother suffers from allergies this has the slightly greater influence on whether their children will have an allergy.

Due to this increased tendency towards childhood allergy, where parents are already allergy sufferers, doctors in the UK and Europe would class such a family as ‘high risk’ for allergic tendencies appearing in children from these families. Families where other children already suffer from allergies are also considered high risk.

However, children do not always develop the same allergies as other family members. Research has shown that the link in atopic families is for children to develop a tendency towards being allergic rather than developing a specific type of allergy. In this way, although the father or mother may suffer from hay fever and be allergic to pollen, their child may, for example, develop atopic eczema or asthma.

In children, allergy commonly follows a particular pattern where an allergic infant often continues to have allergies as a toddler and throughout their childhood, leading to a lifelong condition. This is known as the ‘Allergic March’, where a child experiences a range of allergic diseases where one subsides but another one develops. In these instances it can often be the case that atopic eczema leads onto food allergy, then asthma, then rhinitis. Alternatively, children can keep one form of allergic disease while gaining yet another. However, all children are different, and having one allergy doesn’t necessarily mean that another particular allergy will follow.

It is important to remember that not all children from atopic families go on to develop allergies. It is just as important for parents who do not suffer from allergies to be aware that one in five children born into non-atopic families also now goes on to develop some form of childhood allergy.

It is clear that genetics alone is not the sole cause of allergies, and it is widely accepted that the environment in which we live also has a great influence on the development of allergies in our children. For these reasons, whilst some families have a greater tendency towards allergy than others, all parents need to be on the lookout for allergy symptoms in their children.

The most important fact to remember is that if a child does develop an allergy, with early diagnosis and treatment of this condition, it will be easier to manage the symptoms and help minimise their effects on the child’s daily life.

Key Points:

• In the UK 50% of children have been diagnosed with one or more allergic conditions
• Families where parents or other children already have allergies are considered high risk for subsequent children developing allergies
• Individuals who have a tendency to develop allergies are called ‘atopic’
• Over half of children from atopic families go on to develop an allergy
• One in five children from non-atopic families goes on to develop an allergy
• The greatest risk of a child developing an allergy is in families where both parents suffer from allergies, although where only one parent has an allergy it is the mother’s allergy history that has a greater influence
• Early diagnosis and treatment of allergies makes managing the symptoms easier