What's in our food: One girl's struggle with her allergies

When Crystal Sharp's friends want to drink a glass of milk, they make sure they move away from her.

Crystal, who turns 13 on January 12, has never had a glass of milk in her life. Even the smell of milk on her friends' breath turned her face red and gave her trouble breathing.

A few years later, tests suggested she had outgrown the allergy, so her mother, Denise Sharp, was advised to test her with a drop of cow's milk in rice milk.

"I was stupid enough to do that," Mrs Sharp says.

"She only had one mouthful. Her tongue went red and sore and she felt sick."

Crystal is among 1 to 2 per cent of New Zealand children born allergic to cow's milk.

She is an extreme case. Unlike 90 per cent of those with the allergy, she did not grow out of it by the time she was five. Instead, her allergies trebled.

She is now allergic to eggs, peanuts and other nuts, fish, shellfish and certain fruits and vegetables such as onions and avocados.

She was given soy milk at three months old, and at first that calmed her down after feeding.

"She had been an extremely scratchy baby," Denise says.

"We found out milk proteins can be passed through breast-feeding."

But when she was six years old, Crystal developed an allergy to soy too, meaning she had to cut out sausages, ham and processed meats.

She also comes out in a rash if she swims in the sea or in a chlorinated pool and is allergic to mown grass, lipstick, powder and latex gloves.

She was moved to Takapuna when West Auckland was sprayed for the painted apple moth last year, but still developed a nasty rash and stomach pains when she went home to Te Atatu a few hours later.

Allergy specialist, Dr Vincent Crump, says scientists simply do not know why some children, like Crystal, have so many allergies.

"We know it's genetic, but a lot of it is bad luck.

"We do annual blood tests to see if she can outgrow it, but she is showing no signs. Her immune system is so abnormal it's becoming less likely she will grow out of it."

Instead, Crystal is forced to adjust. She eats what her mother calls "old-fashioned foods", and calcium tablets to provide the nutrients most people get from milk.

"There's not a lot of junk food that she can eat so she eats a very healthy, well-balanced diet," Mrs Sharp says.

Although many sports are impossible, she has started horseriding but wears trousers, boots and gloves to avoid direct physical contact with the horse.

She enjoys drawing and is a voracious reader and hopes that her allergies will eventually diminish.

"There is always hope," says her mother.