‘Atopic’ refers to diseases that are hereditary and therefore tend to run in families; they also often occur together. It’s common for someone to have eczema, a form of allergic rhinitis (like hayfever), and asthma (though they may have these at different times of their lives); someone that is ‘atopic’ (or a family that is ‘atopic’) are also more likely to have food allergies. It’s possible to have mild cases of these diseases (like eczema) and not be atopic; it requires a doctor’s diagnosis and the demonstration of allergic antibodies.
It’s worth researching ‘atopy’ when it’s diagnosed by a doctor because it helps to have an awareness that your toddler that has eczema has a higher chance of developing asthma later in childhood (see ‘The Atopic March’). It also means that if one parent has hayfever and another has a mild food allergy, children have a greater chance of being ‘atopic’ although they may exhibit this differently than either of their parents.
If you have suspicions of a food allergy, allergic rhinitis encompasses more than just hay fever in response to pollen. In general terms it means that an allergen has caused the inside of the nose to swell and become inflamed. This can cause cold-like symptoms, such as sneezing, itchiness, and a blocked or runny nose. Ongoing inflammation in the sinuses can also result in ‘allergy shiners‘ (like a continually bruised look beneath the eyes even if sleep hasn’t been disrupted). The problem is that under 5’s do get a let of colds and it can be hard to distinguish between an actual cold and a warning sign that there is an underlying allergy. If there’s a family history of atopic illnesses or your child has been diagnosed with other atopic illnesses (like eczema) then it’s worth reading up on the most common food allergies and discussing these with your doctor. For most children, a food allergy will result in them creating IgE antibodies which can be screened for with skin or blood testing.
Key source: “Eczema: The Essential Guide” by Sharon Dempsey