Health Why Do We Have Allergies? It May Be an Evolutionary Strategy

We know how they work, but why we develop them is still a mystery. Carl Zimmer recounts his encounter with immunologist Ruslan Medzhitov, who has an original allergy theory.

For me, it was hornets.

It was a summer afternoon. I was 12 years old and running through a wild field near a friend’s house. I kicked a hornet’s nest the size of a football. A swarm of angry insects descended on my leg. Their stings felt like hot needles. I swatted them away and ran for help, but within minutes, I realised something else was happening. A constellation of pink dots had appeared around the stings. The rash on my skin was swelling and moving up my legs. I was having an allergic reaction.

My mother’s friend gave me some antihistamines and loaded me into her car. We drove to the county hospital, and as we drove, I grew more and more terrified. I had a vague idea of ​​the terrible things that can happen when allergies kick in. I imagined hives spreading up my throat and choking me.

But I lived to tell this story. At the hospital, the rash cleared up, leaving me with a terrible fear of hornets. A test later confirmed that I am allergic to hornets—not bees or wasps, but to the type that stung me.

The doctor in the emergency room told me that if it were to happen again, I might not be so lucky. She gave me an EpiPen and told me to inject it into my leg in case it happened again. Epinephrine raises blood pressure, opens the airways, and probably saves my life. I was lucky: it happened one afternoon 35 years ago, and I haven’t encountered another hornet’s nest since. I lost my EpiPen years ago.

The collective burden of allergies is enormous, but treatments are limited. The EpiPen can save lives, but available long-term treatments offer questionable results for those exhausted by mould allergies or the annual release of pollen. Antihistamines often reduce symptoms, but like other treatments, they cause sluggishness and drowsiness.

WHAT’S HAPPENING IN THE BODY? If scientists understood allergies, we could invent better treatments. However, allergic reactions are based on a tangled web of causes: out-of-control cells, chemical release, and signalling. Scientists have only mapped out part of the process. And an even bigger mystery is underlying this biochemical web: Why do allergies exist?

“That’s the question that fascinates me,” Ruslan Medzhitov told me recently. “It’s a big, fundamental problem, but it’s completely unknown.”

As we stroll through his lab on the top floor of the Anlyan Center for Medical Research and Education at Yale School of Medicine, his staff of postdocs and residents work among large tanks of oxygen and incubators filled with immune cells. “It’s a big mess, but it’s productive,” he tells me with a shrug. Medzhitov’s face resembles a boxer’s, massive, round, with a broad, flat nose, but he speaks with a soft elegance.

Medzhitov’s “mess” has been exceptionally productive.

A NEW THEORY. Now Medzhitov is tackling a question that could change immunology again: Why do we get allergies? No definitive answer exists, but the most widely accepted theory suggests that allergies are a botched defence mechanism against intestinal parasites. In the industrialised world, where infections are rare, this system overreacts against harmless targets, making us feel sick.

Medzhitov says this theory is wrong. Allergies aren’t just a biological mistake. Instead, they’re an essential defence against harmful chemicals—one that served our ancestors for tens of millions of years and continues to this day. Medzhitov admits it’s a controversial theory, but he’s confident history will prove him right. “I think there’s going to be much resistance to the idea for a while,” he tells me. “And then everyone will start saying, ‘Oh yeah, that’s clear, that’s obvious.’ ”

Sunday, 65 years old

For me, it all started around the age of 40 with a series of allergies, rhinitis and a runny nose, 12 months a year without a break. At first, I thought they were just colds. I took antihistamines, but they didn’t work.

Then, after the allergy test, they gave me sprays to do twice a day, but over the years, the situation kept getting worse. I also started having breathing problems, constant cough, and tightness in my chest. I struggled to do everything, even cleaning the house.

After almost 20 years of this agony, I was giving up. I was told that I would have to live with it, but then two years ago, after a series of more in-depth tests, I was finally diagnosed with Severe Asthma.

Thanks to the support of my pulmonologist, I was included in the biological therapy program. I do one treatment a month, and my life has changed; I feel reborn. Of course, I still spray twice a day and take an antihistamine pill in the evening, but I no longer feel that constant suffocation sensation that I had before. I get tired, but I can handle the situation.

I no longer have rhinitis, colds and bronchitis. I no longer have a cough that used to be constant all year, all day. Above all, I have started volunteering again, a passion that I have always had that makes me feel mentally and physically good.

As a volunteer, I work in emergencies, and it was bad not to be able to run, climb stairs, or not to support those who needed it. Now, however, I feel useful again because I can help others. I have also returned to being able to do cardiac massages. And all this is thanks to the right diagnosis.

ALLERGY TO INHALANTS

Debby had been suffering from allergic reactions for years when he accidentally bit his lip and came into contact with inhalants. To avoid swelling that started from the lip, red skin patches associated with burning and other unpleasant symptoms, he was forced to take antihistamines and cortisone, and the situation was rapidly worsening. There was no logical connection for certain reactions occurring at any time of the year. During the allergic reaction, as he reports in the following testimony, his lower lip reached his nose because of how swollen it was. He diligently went through the entire Total Reset process, also carefully addressing emotional blocks. Today, he has stopped taking any medicine, and since the end of the treatments, there have been no more symptoms of any type or intensity.

“It’s been a long time since I started suffering from allergies, but in recent years, the episodes have intensified to the point of requiring the use of antihistamines and cortisone drugs, and on one occasion, I had to seek emergency care.

They told me about the Total Reset method in January of this year. Encouraged by my life partner, I participated in an initial interview with Debby, who explained how the entire process would unfold and what techniques and procedures to implement.

The entire cycle of weekly sessions ended at the end of July. During the process, there were restrictions to be followed with care and attention, particularly on what foods to eat in the hours following each treatment and what to avoid. There were positive signs right from the start, followed by moments in which some allergic reactions occurred, albeit milder. But this did not discourage me from continuing the treatment, also because I was aware that this could happen.

Despite some small sacrifices, I can finally say that I feel good today because I consistently applied the method.

For this, I want to thank Debby for her dedication, determination, and professionalism. She accompanied me through every phase of the treatment.

Thank you