NICOLE Lenoir-Jourdan is a vegetarian, so having an allergy to meat was the last thing she expected.

But the Pymble publicist knew something was very wrong. She was having allergic reactions to food she’d never had a problem with, like yoghurt, baked beans, and nuts. A few months before she’d been bitten by a tiny tick in her garden and had an extreme local reaction.

‘‘I tell you, I looked like the elephant man,” she says. “My whole head swelled up. It was not normal. I went to a number of doctors and they all went, ‘Oh yeah, you’ll be alright’.’’

None mentioned that a severe local reaction to a tick was a risk factor for developing mammalian meat allergy (MMA), an emerging allergy where the tick’s saliva changes a person’s immune system to start reacting to the meat of mammals — beef, pork, lamb and sometimes even dairy and gelatine.

What Lenoir-Jourdan eventually discovered was that she’d acquired mammalian meat allergy from the tick bite, and she was in the 10 per cent of those who are also allergic to mammalian meat derivatives, like dairy and gelatine.

“I found out that all the foods that were making me sick were either dairy or had meat derivatives in them. The nuts I was eating came from China, where they spray nuts with meat flavouring,” she says.

Having an allergy to mammalian meat caused by tick bite sounds absurd, but for a growing number of Sydneysiders there’s a lot of chicken and fish on the menu now.

If someone presents at Mona Vale hospital with a severe allergic reaction in the early hours of the morning the first thing doctors ask is if they’ve eaten meat for dinner. The second is when they were bitten by a tick.

Clinical Associate Professor Sheryl van Nunen discovered the link between anaphylaxis to mammalian meat and Australian paralysis tick bite in 2007. Back then it was a relatively rare occurrence but fast forward nearly 10 years and she diagnoses a new case of MMA daily at her Chatswood rooms.

It’s estimated there are well over 1000 cases on Sydney’s northern beaches alone. Numbers are so high on the north shore that a diagnosis of MMA in adults, commonly anaphylaxis, is as prevalent as the commonest food allergy in adults, peanut allergy.

Dr van Nunen says Mona Vale Hospital emergency department, which is in a hot spot for ticks, is well aware of the allergy.

“I’ve been saying for years … if you have someone who has a middle of the night anaphylaxis, the diagnosis is mammalian meat allergy after tick bite until proven otherwise,’’ she says.

Unlike traditional food allergies MMA has a delayed reaction of anywhere between two and 10 hours. Most reactions happen between four to six hours after ingestion. Allergic symptoms vary, from hives, to gastrointestinal pain and anaphylaxis.

It’s thought that there are many people who experience milder reactions, such as delayed stomach pain after eating meat, who are unaware they have MMA.

There is still ignorance in the medical community, too. Dr van Nunen says it can be a struggle for people to get diagnosed (which involves a simple blood test). “Yesterday I was seeing a lady who had to struggle for her diagnosis to be found and recognised and it’s difficult enough to have this problem without needing to push for your diagnosis.”

Jana Pearce was diagnosed with MMA in 2010, but not after a lot of blank looks from doctors.

“Unfortunately, the most difficult to convince have been the medical doctors and other health professionals,’’ she says.

“Because they didn’t learn it in medical school, it means it doesn’t exist. I often got the feeling I might as well be from another planet the way they were looking at me. I actually had one specialist say to me ‘Ticks are parasites. They don’t kill their host’.’’

Ticks are a problem on the whole of the eastern seaboard of Australia, which means there’s roughly 50 per cent of the population at risk of getting MMA. So, why is this allergy growing at such a rate and why are some places, like Sydney’s northern beaches such hot spots?

Dr van Nunen blames the proliferation of bandicoots. And this is where the allergy gets even stranger. When the tick feeds on a bandicoot or other small mammal, it picks up a small amount of alpha-gal from its blood, which is transmitted from the tick’s gut into the human when the tick is pulled off. It is this sugar that people with MMA become allergic to.

“What I often see is when people are starting to report bandicoot holes in their backyard, that’s when they start to get bitten by ticks,” Dr van Nunen says.

The other thing most people with MMA have in common is a large local reaction at the sight of a tick bite that proceeded becoming meat allergic.

Pearce didn’t even know she had tick bites when her legs swelled up.

“I was walking through bushland in Sydney’s Lane Cove National Park and was bitten by ticks so tiny you practically need a magnifying glass to see them. I had the world’s itchiest rash on both legs from knee to hip and had no idea at the time that these itchy lumps were burrowing ticks,’’ she said.

Ten days later she was hospitalised with anaphylaxis six hours after eating red meat.

“I’ve had two life-threatening anaphylaxis episodes and had to be ‘brought back’ from both. I felt I’d lost control of my fate. I could eat something accidentally and just stop breathing. I was lucky both times that I was not on my own. It left me afraid to be on my own as I would not have time to administer Epipens, and phone an ambulance for help,’’ she says.

It’s a huge lifestyle change and Dr van Nunen says she sees many of her patients go through a grieving period as they accept their diagnosis.

“I had fear of outdoor activities that involved grass, shrubs, undergrowth,” says Pearce. “I still walk in the centre of tracks or footpath, well away from shrubs on which there may be a tick.”

And it’s the end of casually eating out at restaurants. Many are so sensitive, they can have an allergic reaction to a food that is cross contaminated with red meat during preparation or serving.

Lenoir-Jourdan only eats at vegan restaurants now, but says she misses the freedom she used to have. “I’d like to go to a restaurant with my family and know I’m not going to die.”

If someone who is meat allergic accidentally eats meat, apart from their allergic reaction, Dr van Nunen describes a strange thing happening.

“Often when they accidentally eat meat they report that the site they’ve been bitten by the tick lights up with swelling,’’ she says.

And yet some people are bitten by hundreds of ticks in their lifetime and don’t get MMA. Dr van Nunen believes they are immune and hold the key to perhaps curing the allergy one day.

Meanwhile, prevention is the best cure. Dr van Nunen advises using an ether-containing spray such as Wart-Off to freeze and kill the tick in situ and letting it drop off rather than pull it out.

This prevents the tick transmitting alpha-gal, and might just mean meat is still on the menu.

For more information visit www.tiara.org.au.