Genny Masterman’s main memories of her childhood are of feeling constantly itchy, tired and bloated. “I had eczema on my legs, arms and all over my scalp ever since I was a little girl,” says 35-year-old Genny.
“It was not only desperately uncomfortable but looked terrible. Then, in my teens, I started to develop a visibly bloated belly, even though I was otherwise perfectly healthy, taking regular exercise and eating well. I also occasionally had cramping and terrible diarrhoea.”
Doctors prescribed creams and oils for the eczema, assuring Genny she would grow out of her symptoms. The bloating and gut pain they put down to hormones; the diarrhoea was “just one of those things”.
But she continued to suffer from eczema, while the gut pain and diarrhoea worsened. “I would be rolling in pain on the bathroom floor every few months,” says Genny, a freelance TV producer from Cheshire.
“Throughout my 20s and early 30s, I became solitary and depressed. I thought perhaps it was psychosomatic, and this was just my lot for the rest of my life.”
Then, three-and-a-half years ago, Genny discovered the culprit for her discomfort. She has histamine intolerance, a condition thought to affect 600,000 Britons - although the number could be even higher since many patients are misdiagnosed for years.
“Histamine is produced by cells in the body when it is undergoing an allergic reaction and it can also be released during an infection,” says Jonathan Brostoff, Professor Emeritus of allergy and environmental health at King’s College, London.
“If the immune system detects something harmful - such as a virus or bacteria - histamine increases blood flow to the affected area.”
While we all familiar with the body producing histamine as a reaction to hayfever, histamine intolerance refers to histamine that enters the body through certain foods. And because it’s ingested and goes through the gut, it produces a different reaction.
“Usually a digestive enzyme in the gut, diamine oxidase, breaks down histamine absorbed through foods,” says Professor Brostoff says. “However, when levels of this enzyme are low, eating some foods leads to a build-up of histamine, producing a wide range of symptoms such as hives, itching, eczema, tummy pain, diarrhoea, rashes and headaches.”
Foods with high-levels of histamine include red wine and beer, cheese, yeast, shellfish, some fruits and vegetables, most fish, chocolate and cured meats such as salami.
Experts believe there may be a genetic link to the condition. Around 80 percent of those affected appear to be women, most being diagnosed in their 40s, which experts attribute to years of misdiagnosis or simply putting up with the condition.
“Lack of awareness and the eclectic nature of the symptoms make diagnosis a real problem,” says Lindsey McManus, of the charity Allergy UK.
Many doctors simply treat what’s in front of them, such as the eczema, headache or diarrhoea, she adds. Even if a food allergy is suspected, standard allergy tests - where small amounts of known allergens are placed on the skin to see if they cause a reaction - will come up negative, as histamine intolerance does not involve an over-reaction of the immune system.
Histamine intolerance is also often wrongly diagnosed as irritable bowel syndrome, explains Ms McManus. “There is a blood test to measure levels of diamine oxidase, but this is far more commonly available on the continent, than in the UK,” she adds.
Indeed, Genny had several food allergy tests throughout her childhood, but they came up negative. She also saw doctors several times every year in her 20s, but they never found the problem.
Meanwhile, she continued eating the foods that contributed to her woes. “My mother always ensured I ate plenty of fish, vegetables and fruit,” says Genny. “In my 20s I became a bit of a foodie - enjoying the odd glass of red wine or beer, and I loved cheese and cured meats. I had no idea all these foods were causing the problem.
“My friends were understanding, but I know it was tedious for them. I was in my 20s and should have been partying - but I’d duck out of anything social.
“I cannot remember feeling anything other than that I was running at 50 percent. At this point food, bizarrely, became my sanctuary of a sort. At least if I was home on my own I could treat myself to a nice meal - but that was just making things worse.”
Then, in June 2007, when Genny was working on a BBC documentary in Austria, she had a particularly bad episode of diarrhoea.
“I managed to crawl into work, but I was rushing to the loo up to ten times a day,” says Genny. “I just had to go to the doctor.”
“I was given rehydration salts to replenish my fluids and told to eat plain food such as rice and chicken. But this time the doctor suggested I have a blood test to check my diamine oxidase levels.
“He said a new condition - histamine intolerance - was gaining a lot of interest and he thought that might be my problem.”
The results showed Genny’s blood contained 1.7 units of the enzyme per litre - normal levels should be 3.5 units per litre.
“After years of suffering, the doctor had found the cause of all my problems. It was unbelievable,” she says. But the smile was soon wiped off Genny’s face. “He passed me a leaflet giving a long list of foods to avoid. It was my worst nightmare.”
She returned to the UK and went to her doctor looking for help with the next steps. But it was here she hit a wall. “My GP was sympathetic but had never heard of the condition. He couldn’t find a dietitian who knew about it either. I had no choice but to read everything I could on the internet, then embark on a four-week elimination diet.
“I cut out bread, cheese, tea - everything that contained histamine. That included sauces containing tomato, vinegar or soy. Even cinnamon, nutmeg and cayenne pepper had to be avoided.”
She adds: “Everything needed to be cooked fresh, so I knew what was going into any meals. I’d spend hours in the supermarket reading the ingredients of foods.”
“That first month, I holed myself up at home. But things started to improve. Six weeks after starting the diet, I felt really good. I had more energy, the depression I’d suffered for around seven years lifted, I didn’t itch any more and my skin improved.
“The bloated stomach I’d had since I was a child disappeared. Thank God I’d been in Austria and seen the doctor I did - otherwise I could still be suffering.’
Lindsey McManus admits that finding a doctor who’ll even investigate a food intolerance isn’t easy. The area is not seen as a priority with regards to funding. As a result, many food intolerances are often not recognised.
Three years on, Genny is so keen to raise awareness of the condition she’s written a book about her experience.
“Life really is good for me now and I want to shout about it,” she says. “With care, I’m able to enjoy a fairly normal diet.
“Also, because my digestive system has been given a rest and isn’t continually bombarded by histamine-rich foods, I can enjoy the odd glass of wine or piece of cheese or salami without fear of such terrible side-effects.
“This diet has completely changed my life and I hope my story will help others.”