If you’re familiar with the world of allergies, you are likely to have heard of someone who had immunotherapy for cats, dogs, grass or even bee venom allergy. But what exactly does it entail? Let’s take a closer look to find out.

In my previous blog post, I explained the similarities and differences between immunotherapy and desensitisation. But to recap: Immunotherapy is when we deliberately expose a patient to a protein of the substance, he or she is allergic to. We tend to start at 1/100 000th or even 1/1 000 000th of dosage, and then gradually escalate to a higher dose.

The goal of immunotherapy is to help your immune system retains the memory of processing an allergen. In doing so, it will continue producing the blocking antibodies preventing an allergic reaction, long after we stop the immunotherapy.

Desensitisation is more temporary. It achieves a state of “sustained tolerance”, where the body is “trained” to handle exposure to a specific allergen in the short to medium term. When a patient undergoes desensitisation, the allergen must be given either for the period it is needed. For example, we can desensitise a patient who is allergic to Penicillin during an infective episode. We can also look into desensitisation for food allergies, this will result in the patient tolerating accidental exposures and potentially saving their lives. Once we stop the incremental exposure to the allergen, the patient is likely to become allergic to it again.

More about oral immunotherapy

Oral immunotherapy (OIT) is when a trained Allergist or an allergy practitioner administers an allergic patient with incremental doses of the allergenic food. We do this to increase the patient’s threshold for triggers. Once we have reached a safe dosage, the patient will have to continue taking the same dose. There is conflicting evidence of the duration of treatment. Currently, we administer the treatment on a continuous basis until proof to the contrary is published.

OIT is a viable option to treat peanut, egg and milk allergies. According to medical studies, between 60% to 80% of patients have been treated effectively.

Although oral immunotherapy can be life-saving and enhance a patients quality of life, we must approach it with caution. This may never be attempted without medical supervision at home or with an inexperienced practitioner. The outcome can be fatal. It is also advisable to still keep an Epipen at hand in the event of exposure to allergens that we did not cover in the therapy.

What are the side effects?

The most common side effects of OIT tends to happen in the gastrointestinal tract. Patients might experience abdominal pain, cramping or vomiting. One of the side-effects is known as Eosinophilic Esophagitis (EoE), a condition where white allergy cells called Eosinophils cause inflammation in the oesophagus. This reaction can lead to difficulty in swallowing, vomiting and abdominal pain. EoE usually clears up once we stop the OIT.

Other side effects include wheezing, hives, an itchy mouth and anaphylaxis.

  • If you’d like to know more about oral immunotherapy and how it might be able to make a difference in your life, please contact us to set up a consultation.
  • You can also read more about immunotherapy on the Allergy Foundation’s website
  • The purpose of this article is to raise awareness of allergies and the treatment options that are available for it. This article should by no means be used, or viewed, as a primary source for medical or other professional advice – please arrange for a personal consultation with your medical practitioner before taking any decisions that could affect the wellbeing of you or your loved ones. Read our medical disclaimer for more information.

Marinda McDonald

Dr Marinda McDonald has offered specialised treatments for allergies for most of her professional career. Read more about her on the home page of this website (allergydoc.co.za).