Asthma Healing

Children with respiratory problems risk being misdiagnosed with asthma if their race is not taken into account, Canadian researchers say.

Levels of nitric oxide – a gas released by cells in the lungs doctors can use as a measure in diagnosing asthma – are different in Asian-Canadian and African-Canadian children than they are in Caucasians, according to new research from doctors from Children’s Hospital of Eastern Ontario and Health Canada.

The finding means what was once defined as the “normal” range of exhaled nitric oxide concentrations in children may be different for children of Asian or African descent.

By not taking factors such as race into account, children with respiratory problems may be misdiagnosed or not properly treated, the researchers write in today’s issue of Chest, the journal of the American College of Chest Physicians.

“Our concern is if someone walks into the doctor’s office to get (this) measured and people don’t keep track of their race, the tests may be misinterpreted,” said Dr. Thomas Kovesi, a pediatric respirologist at the Children’s Hospital of Eastern Ontario.

After examining a large pool of data from children in grades 4 through 6 in Windsor, Ont., the doctors found Caucasian children had an average fractional concentration of exhaled nitric oxide of 13 parts per billion but the average level was 24 parts per billion for Asian-Canadians and 18 parts per billion for African-Canadians.

The study also found a slight increase in exhaled nitric oxide levels in older and taller children.

Nitric oxide tests are relatively easy to do – children breathe into a machine that measures how much nitric oxide is exhaled. If levels are high, that can indicate a person has asthma, or, if they are asthmatic, it can show the disease isn’t properly controlled. However, there are few machines measuring nitric oxide in Ontario, as the Ontario Health Insurance Plan does not cover the costs of the test, Kovesi said.

Dr. Mark Greenwald, a spokesperson for the Asthma Society of Canada said there are genetic and racial differences in terms of medical problems and its important to know them. “Can it be used tomorrow? No it can’t be because we don’t have the ability to do the test easily and cheaply,” Greenwald said.

“The bottom line specifically for asthma is treat it extremely aggressively until you get complete control of the disease,” he said, adding that edict holds true regardless of race.

In people with asthma, inflammatory cells get into the airways and cause the asthma, explained Kovesi. “If you burn your hand on the stove, you get inflammatory cells into the skin and that is what makes the hand raw, weepy or irritated,” he said.

“In diagnosis or management of asthma doctors tend to look at size of airways. We know if you have asthma it makes your airways narrower. This nitric oxide testing not just looks at the effects of asthma but what causes the airways to be narrowed, which is the inflammation.”

Tracking exhaled nitric oxide is one of the most important ways doctors have to “determine when an airway inflammation has worsened, so treatments can be modified to improve control”, said Kovesi.

Nearly 3 million Canadians have asthma, according to the Asthma Society.

Defined as a “chronic inflammatory disease of the airways,” symptoms include wheezing, tightness in the chest and shortness of breath and it can be triggered by viral illnesses, fumes or allergies. Those with moderate to severe asthma can take anti-inflammatory drugs daily to control the illness.