The winter cold and flu season may be drawing to a close, but many people in the Ottawa region won't be able to put away the tissues. The rapidly melting snow is uncovering moulds that can cause sneezing, wheezing, rashes and other allergic reactions in some people.

These moulds are some of the largest contributors to seasonal allergies. One of the most common types is called "snow mould," a fungus that grows in moist conditions at temperatures around freezing.

Melting snow releases moulds and pollens into the air, causing allergic reactions in some people. (CBC)

The spores aren't in the snow, but hidden below the soil. Once temperatures begin to warm up, these moulds escape their snowy prisons and get into the air.

"Then people breathe them in and have these allergic reactions," said Dr. Antony Ham Pong, one of the city's top allergy specialists.

Ham Pong said the recent stretch of warm weather has him already seeing patients with allergy symptoms that include congested noses and puffy, itchy eyes. Asthma may also occur in some cases.

Edith Laflamme brought her five-year-old son Justin in recently. Tests revealed Justin is affected by a variety of moulds, including snow mould. Laflamme said his springtime allergies are almost like having a constant cold.

"He sneezes a lot and he gets severe rashes on his body," she said. "The coughing is, I think, the hardest for him."

For Justin, and thousands of people in the Ottawa area, the remedies are antihistamine medications and allergy shots.

Ham Pong said people in this region have an especially tough time with allergies because the Ottawa valley tends to trap pollen and moulds. He also said the spring allergy season is only just beginning.

"The mould count in the air is still not too high," he said. "But if this warm weather keeps up and the nighttime temperatures continue to be above zero, then the mould will become more a problem."

A survey commissioned by pharmaceutical giant Johnson & Johnson suggests as many as 10 million Canadians may suffer allergy symptoms and that more women than men admit to symptoms. The survey also found that 55 per cent of Canadians claim their allergies cut into their productivity and more than a quarter say they'll limit their outdoor time to prevent the onset of symptoms.

The survey indicated that Ontario suffered the highest rates of seasonal suffering while Atlantic Canada reported the lowest rates.