This story was originally titled "Extreme Food Allergies: Survival Tips," in the March 2008 issue. Subscribe to Canadian Living today and never miss an issue!

When she was seven years old, Susan Hickman, 57, from Ottawa, moved to the coastal town of Sept-Îles, Que., where shrimp was part of her everyday cuisine – and in her favourite dish, shrimp fried rice. But as much as she adored shellfish, at 28, Susan developed a life-threatening allergy to all types of shellfish. Now eating even the tiniest morsel of her favourite food could kill her.

Between three and four per cent of Canadian adults, and nearly six per cent of children, suffer from food allergies, says Dr. Susan Waserman, an associate professor of medicine at McMaster University in Hamilton. And for unknown reasons, the numbers are growing. Although most people with a food allergy have non-life-threatening symptoms, such as a skin rash, itchy throat or gastrointestinal upset, everyone has the potential to develop severe, extreme reactions similar to Susan’s, says Waserman.

Unfortunately, there is no way to predict who will develop food allergies or progress to getting life-threatening reactions. In Susan's case, her ability to eat shellfish changed abruptly in the late 1970s, when she was living in Sault Ste. Marie, Ont., working at a newspaper. One night she was at a Chinese restaurant eating a beef-and-green-pepper dish; later that evening, red itchy hives broke out all over her face and mouth, and her throat swelled so much she was gasping for air.

"I went to the hospital, where I was treated for an allergic reaction," says Susan, who had never been aware of having allergies before. The whole event came as a shock, and she had no idea what triggered it. It took more than a year, and two additional near-death experiences, before she discovered shellfish was the culprit. Looking back she guesses that the beef dish must have been made with oyster sauce, which is common in many Chinese dishes.

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