• Royal Free Hospital and UCL Clinical Immunology and Allergy Consultant Prof. Suranjith Seneviratne on allergies and immune system disorders

Something little spoken about but posing significant health concerns are allergies and immune system disorders. About 30-40% of the world’s population is affected by allergic conditions and asthma – a very common immune-related condition which affects about 81 million children worldwide. 

On ‘Kaleidoscope’ was an expert in allergology and immunology, a Consultant in Clinical Immunology and Allergy at the Royal Free Hospital and University College London (UCL), England, directing the Centre for Mast Cell Disorders, Professor Suranjith Seneviratne. He joined us to discuss this area of medical health that is not often focused on. He is also the President of the United Kingdom (UK)-Sri Lanka Immunology Foundation, contributing significantly to immunology education in Sri Lanka. 

Following are excerpts from the interview:

What are the most prevalent allergic and immunological disorders currently observed in Sri Lanka?

Allergic disorders are in relation to what we inhale, which could be a dust mite allergy, pet allergy, mould or cockroach-related allergy. When it comes to the next group of conditions, it’s food allergies, which is quite significant in Sri Lanka. The third group is medication related allergies, including a whole range of drugs, antibiotics and a group of drugs called non-steroidal anti-inflammatory drugs. These are not really allergies but sensitivities, taken as a simple manifestation.

What has contributed to the increasing prevalence of both allergies and immunological disorders?

Lifestyle factors are the biggest contributor. When I went to the UK in 1999 for my Doctor of Philosophy (PhD), allergic and autoimmune disorders weren’t seen as major issues in Sri Lanka. But, as lifestyles changed, with children spending more time indoors, eating out more, and living in apartments with air-conditioning, allergies began to rise.

What recent advancements are there in immunology for treating disorders?

Immunotherapy has been around for over 100 years, starting at the St. Mary’s Hospital in London for pollen and bee and wasp sting allergies. Initially, it was injectable, causing adverse effects. Now, we use sublingual therapy – placing a tablet under the tongue daily for three years. For severe allergies, biological treatment, which are injectable under the skin, offer significant advances for patients with severe asthma, allergies, or anaphylaxis.

What role does genetic predisposition play in the development of autoimmune diseases?

As in any autoimmune or allergy disorder, genetics definitely plays a part. If you have a parent or both parents with an allergic or autoimmune disease, it has a contribution towards the child getting the allergic or autoimmune disease. But, in addition, it’s a combination of genetic characteristics together with environmental factors. That interaction with the environment can alter some of the elements in the gene. We use this term called epigenetics – it’s just technical – but the way the gene behaves can be affected by the environment. So, it’s a combination of the two.

Any examples of that?

Our lifestyle, including fast food, can influence how genes behave. In certain environments, allergens or autoimmune triggers might not usually cause a reaction. However, factors like pollution, climate change, and low vitamin D levels can affect the gene function, leading to the manifestation of diseases.

How has Covid-19 affected all this?

We know that we went through a very difficult time with Covid. But, we learned a lot too, in terms of preventing disorders. For example, I think that the vaccine scenario will improve a lot for chronic infections and cancers.  Cancers, which were not treatable, are now treatable – certain vaccines are being trialled for cancer, and that knowledge came from the Covid pandemic, despite it having a big, big effect on us.

How can early intervention help or reduce the risk of allergies in later years?

It can in several ways. This relates to the hygiene hypothesis, which suggests that being too clean might actually increase the risk of the immune system going off track. For example, researchers found that children living on farms in Switzerland had lower rates of asthma compared to children in cities. That was the first indication.

In Israel, researchers noticed that Jewish children were introduced to peanuts very early in life, unlike in London, where peanut introduction was delayed. As a result, peanut allergy rates were much higher among children in London. So now, we don’t delay in introducing certain foods. 

In the past, when a mother was pregnant, she was often advised to avoid nuts for the baby’s benefit. But, that’s no longer recommended, because holding back these foods can increase the risk of allergies rather than prevent them.

What challenges exist in diagnosing and then managing immune disorders?

I think it’s an evolving field, and we are learning a great deal. Twenty-five years ago, what we knew was quite different from what we understand today. So, the revolution in this area has brought significant change, because alongside the basic tests that we routinely perform, we now proposed two genetic tests. 

The major issue however is cost; that is where there’s a big difference between the West and the East, because immune tests are expensive as they must, for instance, be conducted in specialised laboratories. But, as more tests become available in India, Southeast Asia, and our region, the prices tend to drop, just like they did with certain drugs.

What needs to be done to improve public awareness and to improve education in allergy prevention and managing it?

Dealing with allergies requires involvement from everyone, not just doctors, but also nurses, teachers, and other healthcare personnel, all of whom should communicate in a way that’s easy to understand. High-level, abstract theories don’t help. Clinicians often emphasise that preventing every infection isn’t good for immune development and that being overly clean can lead to health issues later.

How do lifestyle factors – diet, exercise, the environment – impact the immune system’s health as well as susceptibility to allergies?

The environment is absolutely key. If you think about it, we carry about 3 kg of bacteria in our gut and there’s no reason to carry that much bacteria unless they’re doing something important. 

The microbiome, as we call it, plays a crucial role. These bacteria constantly communicate with the immune system, influencing immune cells and how they behave. This is why antibiotic overuse and misuse are so harmful; they disrupt that ecosystem. 

Then, there’s exercise and nutrition: if your diet is poor, your vitamin D levels are low, and you’re not active, it puts extra strain on the immune system. That’s because the immune system ends up handling tasks it shouldn’t have to. Its primary role is to protect the body from dangerous viruses, bacteria, and fungi. But, if it’s busy reducing inflammation caused by a bad diet, for example, then you’re wasting valuable immune resources.

If you’re looking at the allergies that Sri Lankans have, what are the allergies with the highest prevalence?

It would be aeroallergens. The house dust mite is the major allergen found in homes. The issue is that houses have changed. People are living in more confined spaces, windows are kept closed, and air conditioners are constantly running – often placed near the bed. Water collects and dust settles on the bed. People are also putting carpets on the floor. Children spend more time indoors in the city instead of playing outside. Secondly, mould allergy and cockroach allergy. Those three are very significant.

When it comes to food allergies, the pattern is different from the UK. There, peanut allergy is more common. Here, it’s other foods: cashew nuts, prawns, crab, and certain kinds of fish. Beef allergy is a concern in Sri Lanka, which we don’t see as much in the UK. It’s a problem because certain components related to beef can be present in vaccines. So, you need to be careful. These are the common allergens. 

As for drug allergies, penicillin is a key example. The United States Food and Drug Administration has noted it too. And I always tell patients, “Don’t just say, ‘I’m allergic to medicines” when you visit a doctor, because then the doctor might avoid giving any treatment at all. Speak with someone, discuss your reactions, and know which medicines you’re allergic to – or at least have an idea – so that suitable alternatives can be used.

How would you advise a household to treat a person with a mild allergy or an allergy that is almost life-threatening?

For a mild allergy, if you want to take an antihistamine, that’s fine. For example, if you have a rash or sneezing in the morning, an antihistamine can help settle it. But, if the symptoms are more chronic and persist for a longer period, then, it’s important to be assessed by a physician.

There are other types of allergies where people develop multiple lumps on the skin, wheals, or hives – what some people might call ‘pulvers’ – and those cases need proper treatment. It’s not just about taking prednisolone or steroids and getting it under control for the moment. It’s important to get a proper management plan and stick to that treatment plan, so that the condition stays under control over time.

What future direction do you see allergology and immunology taking to address the growing trends of allergies and immune disorders?

Immunology and allergology are fields that people didn’t really understand many years ago.  But, especially after Covid, there’s more awareness; people want to understand how the immune system protects the body. 

Immunology specialists are now involved in almost every field. Rheumatologists, cardiologists, infectious disease specialists, nephrologists, and other specialists need to understand aspects of immunology. There’s a lot of crosstalk and interaction between specialties. Advances in immunology are now feeding back into core specialties like cardiology and respiratory medicine. So, collaboration is essential.

Why did you get interested in specialising in allergology and immunology?

It happened somewhat by chance. I received a Commonwealth Scholarship to go to Oxford University to read for my PhD. At the time, my supervisor was a dermatologist and the project that I was given focused on studying T-cells in eczema and asthma. From that point onward, I began training as a clinical immunologist. I first trained as a clinical immunologist and then continued along that path. And for the past 25 years, I’ve been working in that field consistently.

(The writer is the host, director, and co-producer of the weekly digital programme ‘Kaleidoscope with Savithri Rodrigo’ which can be viewed on YouTube, Facebook, Instagram and LinkedIn. She has over three decades of experience in print, electronic, and social media)