ACK! Why am I suddenly allergic to prawns?

WORDS PANK JIT SIN

Can adults develop allergies? A little while ago, the smarties at HealthToday were discussing about allergies and the topic of adult onset allergies came up. A few of us were afflicted by allergies that developed in adulthood and post pregnancy. That got us intrigued and we went snooping around for further information. Beyond searching for literature on adult onset allergies, we also spoke to Dr Kent Woo, a prominent allergist and immunologist at Gleneagles KL.

We tend to think of allergies as something that develops during childhood and stays with us for life. It is rare to hear someone growing out of their allergies without any medical interference. These allergies include asthma, eczema, allergic rhinitis, hay fever and food allergies.

According to Dr Woo, adult onset allergy technically means a newly developed allergy during adulthood as opposed to childhood. He said: “Allergy can develop during all stages in life. However, it is more common to develop food allergies as a child and medication allergies as an adult.” Dr Woo notes an interesting observation in his practice—an increase in allergic contact dermatitis towards cosmetics in menopausal women. He postulates it could be caused by hormonal changes causing the allergen sensitization to previously tolerated cosmetics.

Regarding treatment, Dr Woo said treatment towards all forms of allergy is primarily avoidance. Medication allergy is a little different and one can opt for desensitization therapy. According to the American Academy of Allergy, Asthma and Immunology (AAAI), drug desensitization or induction of drug tolerance, is “a method of safely administering a medication to a patient who is allergic to it.” The procedure is done by administering an extremely small dose of the medication to the patient. This dose is increased slowly at regular intervals until the full dose is achieved. Once the drug is discontinued, the patient returns to his or her previous allergic state.

In the case of aeroallergens such as dust, pollen or spores, a treatment called allergen specific immunotherapy can be done. The treatment is a disease-modifying therapy which is useful in treating allergic rhinitis and conjunctivitis, allergic asthma and insect hypersensitivity.

It is very important that any treatment involving allergies be carried out by a doctor or specialist, specifically an allergist, as there is a risk of developing anaphylactic (life-threatening) reaction to the medication or treatment.  An allergist will be able to tailor a plan specific to your allergies.

How common is adult onset allergy?

While we like to believe that allergies often afflict the young, the truth is allergies can develop during all stages in life. A rather recent research looking at adult-onset food allergy claims that 5% of adults and 8% of children are affected by food allergies.

A separate survey carried out in the US comes up with an even more alarming figure—almost one quarter of adults reported developing adult onset food allergy while about 55% noted they had childhood onset food allergies. The study, which was carried out on over 40,000 adults revealed that the most common allergies reported by adults were shellfish, milk, wheat, tree nut and soy, in that order. The researchers were taken aback by the number of shellfish allergies and it was noted that a substantial number of them ended up in the emergency department due to anaphylactic reactions.

Nobody really knows why someone can be perfectly fine with a type of food and suddenly develop allergy to it later in life.

Does ethnicity affect my risk?

Apparently, one’s ethnicity determines the risk of developing certain types of allergies. Asians, Hispanics and persons of African descent are at higher risk of developing shellfish and peanut allergy than Caucasians.

Another observation from the survey was that being female and getting older puts one at increased risk of developing adult onset food allergy.

Some people may not recognize they have a food allergy and believe they are merely intolerant to it, thus not seeking help. We all know someone who avoids certain foods because it makes them queasy or it gives them tummy aches.

If consuming a type of food always seems to bring you discomfort or trigger other symptoms, perhaps you might want to consider the possibility of it being a food allergy. So, with that in mind, what foods do you avoid? What foods make you feel unwell? Could it be food allergy? We’ll leave you with that thought, but at least now you know better and can look for treatment if necessary. HT

References:
1. American Academy of Allergy, Asthma and Immunology. What is drug desensitization? Retrieved from https://www.aaaai.org/conditions-and-treatments/library/allergy-library/drug-desensitization.

2. Warren C., et al. (2018). Prevalence, severity, and distribution of adult-onset food allergy. J Ann Allergy Asthma Immunol;121:S1–S17.

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