Seven-year itch for a cure
Businesswoman Fenny Kwong was on one of her frequent trips abroad when she caught the flu in Paris. Like most people, she shrugged it off as a passing inconvenience, but her sniffles and stuffy nose eventually turned into asthma.
Not long after the flu, Kwong (whose name has been changed for patient confidentiality reasons) suffered debilitating attacks that left her short of breath and struggling to sleep. The 43-year-old would feel so winded and weakened that she had trouble getting around.
Her doctor tested her and found that she was allergic to cat dander and house dust, and concluded that her asthma was triggered by these allergens. He gave her the standard arsenal of asthma control and relief drugs. But Kwong's asthma attacks persisted.
Over the next seven years she scoured three continents for relief, seeking treatment from doctors in the United States, Britain and Hong Kong to no avail. When she was 50 years old Kwong visited Dr Lee Tak-hong, director of Hong Kong Sanatorium and Hospital's Allergy Centre.
By this time, lung function tests showed that Kwong's organs were only functioning at 60 per cent capacity. Every breath seemed a Herculean effort, draining her of strength and energy.
Lee says the onset of asthma after a viral infection is quite common, although why this happens is unknown. But the late age at which Kwong experienced her first asthma attack was unusual. Lee was not convinced that she suffered from typical asthma.
He dug deeper into Kwong's medical history and asked her to list all her ailments, even if she thought they were unrelated to the asthma.
Several of her reported ailments were of particular interest. Firstly, Kwong had suffered rhinitis and sinusitis for the past 15 years. Secondly, she would get flushed and suffer a horrible itch all over her body if she drank alcohol. And lastly, occasionally she would suddenly break out in hives.
Combined with Kwong's unusually late onset of asthma, these conditions pointed Lee to a very different disorder than true allergic asthma. He suspected the source of her torment was a pseudo-allergy.
The condition, Samter's triad, presents with a specific combination of symptoms: asthma, nasal problems and a hypersensitivity to salicylates (the active ingredient in aspirin).
Salicylates block an enzyme called cyclooxegenase-1 (COX-1), resulting in an overproduction of leukotrienes, substances that trigger contractions in the airway muscles. An overproduction of these fatty molecules results in severe inflammation, causing asthma and allergic rhinitis symptoms.
(Childhood onset asthma, on the other hand, is caused by the swelling and constricting of airways due to the antibody immunoglobulin E, which the body produces in reaction to allergens.)
Further clues that supported Lee's theory were Kwong's symptoms of itchiness and hives, which are also known symptoms of salicylate intolerance.
Salicylates are found in plants, fruits and vegetables as a kind of natural protection against insects and disease. Examples of such fruits and vegetables include apples, avocados, peaches, dates, kiwi fruit, grapes, strawberries, cherries, cauliflowers, cucumbers, mushrooms, radishes and broccoli.
Many dry spices, tomato sauce and soy sauce also contain the chemical, as do beverages such as tea and alcoholic drinks. Salicylates are also found in everyday health and beauty products.
So even if Kwong did not take aspirin, the substance could enter her system through eating and product use.
Lee says it is likely that the levels of salicylates built up in her system, initially causing the nasal problems, itchiness and hives, before the levels finally broke her body's threshold and resulted in the asthmatic symptoms.
He advised Kwong to cut salicylates from her diet and to closely monitor the ingredient lists of the personal products she used. Meanwhile, he briefly increased the dosages of the asthma control medications she had been taking.
Although the extensive list of foods and products to avoid was daunting, the idea of spending the rest of her life trying to catch her breath was much worse.
In three short weeks, Kwong's seven-year battle for breath was over. Her symptoms vanished and a test showed that her lungs were functioning at 100 per cent. With the right diagnosis and treatment plan under Lee, Kwong was able to discard her asthma medication.