The New Straits Times, May 7, 2000
By Prof Dzulkifli Abdul Razak
May 3 was World Asthma Day, with the theme: 'Let every person breathe'. This is an apt reminder, as many of us take breathing for granted!
Breathing difficulties, caused by ailments like asthma, can be so serious as to cause death, although this seldom heard of.
At the rate the environment is being polluted, asthma is gradually taking centrestage in the lives of many. We have just to remember the haze of 1997 to realise this. Already, asthma is suspected to be the most common chronic childhood illness. It is also a more common medical emergency involving adults.
Asthma is a non-contagious chronic condition that affects people of all ages, races and sexes, in which their airway passages (like the bronchus) are more prone to constriction (thus, bronchoconstriction) compared to that of a normal person. Thus, asthmatics are more sensitive when subjected to some sort of a stimulus, usually an allergy substance or allergen.
When an allergen comes into contact with the senstive airways of an asthmatic, it causes the release of a host of chemicals known as 'mediators'. These mediators are responsible for the immediate constricting or narrowing of the airways. The degree of sensitivity and narrowing varies, depending on the types of allergens involved. This is followed by a swelling (oedema) of the cells that line the airways, causing further narrowing the airways.
The release of mediators has been associated with various allergens, which are mostly related to air pollutants -- such as dust, pollen, cigarette smoke, and even animal fur. They can also be viral infections and food additives, for example those containing the additives - sulphites and metasulpihtes, which are more often found in packaged foods. These examples are by no means exhaustive.
Individuals can be allergic to a range of substances, some more than others, and many are yet to be identified.
Some of these aspects of asthma have been well dealt with in the article 'Empowering asthmatics' by Tahir Ismail (NST, April 27).
Asthma, or bronchoconstriction in general, can also occur following the use of certainn drugs. This is known as 'drug-induced asthma'. One of them is aspirin.
More generally is the class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs) which are used to treat rheumatoid arthritis and osteoarthritis.
The drugs mentioned above can put asthmatics in a vulnerable position. Some of the common symptoms are running nose, shortness of breath, wheezing and other forms of breathing difficulties. Skin rash and hives are also common.
In rare cases, life-threatening anaphylactic shock can occur.
Aspirin-like substances, called salicylates can also be found in food, ranging from spices, vegetables and herbs and fruits. Reportedly common examples of spices with high salicylates are cinnamon, cumin, tumeric and paprika; whereas the common herbs are celery seed and sesame seed.
Most vegetables are said to contain salicylates except, for example, cabbage, beansprouts, lettuce and peas. Cucumbers are particularly high in salicylates, as are fruits except for example bananas, mangoes, papaya and pomegranates.
Food with low salicylate content includes meat, fish, shellfish, milk, cheese and eggs, rice, barley and wheat. Many processed foods and instant meals are also reported to contain salicylates.
Because allergic reactions to aspirin and aspirin-like substances can be insidious and manifest gradually, one needs to be watchful.
Because of this fairly well-documented asthmatic reactions to aspirin, many people are turning to a relatively safer analgesic like paracetamol.
Until today paracetamol is not widely implicated to cause asthmatic allergic reactions.
But recently the possibility has been raised in the scientific journal, Thorax. A research article claims that paracetamol has been positively associated with asthma at least in adults. And since the pulmonary antioxidant, glutathione, may limit airway inflammation in asthma, and paracetamol depletes the lung of glutathione in animals, it has been suggested that paracetamol might reduce levels of the lung protecting antioxidant glutathione.
The article also noted that frequent paracetamol use was also positively associated with symptoms like rhinitis normally seen in allergic reactions.
The researchers, from Guy's, King's and St Thomas' School of Medicine in UK, concluded that the frequent use of paracetamol may contribute to asthma morbidity and rhinitis in adults.
Another recent report also associated alcohol with asthma. While this may be common knowledge to many asthmatics, the report suggests that wine appears to be a particular culprit. This is based on an Australian study reported recently in the Journal of Allergy and Clinical Immunology, where responses to a food allergy questionnaire completed by 366 adult asthmatics were analysed.
The researchers noted that although most asthma attacks triggered by alcohol are mild, the study findings suggest that severe attacks may also occur. Wines, both white and red, were most commonly cited as a cause, and reactions were usually seen within an hour of taking the drink.
This finding is relevant to the Malaysian scene since wine has been reported gaining popularity. According to a local wine distributor, although the consumption of cognac and beer has been hit, not so for wine. In 1999, for example, 10 new wine specialty outlets have opened in Klang Valley.
Further, the research showed that such reactions were more often in women, namely those taking oral steroids, those who had their first asthma attack at a relatively young age, and those who had visited an alternative medicine practitioner for asthma treatment. The researchers also saw significant associations between wine-induced asthma and asthma induced by aspirin, and NSAIDs as well as by sulfite-containing foods.
Thus unlike atmospheric allergens, those associated to food and drugs can be easily avoided and thus preventing an asthma attack. What is important is an increased awareness among asthmatics and their guardians as to some of the potential sources that could lead to asthma.
At all cost they should be identified and avoided or consumed sparing. Product labelling is an important precautionary act to help them.
For more information, contact the National Poison Centre at Universiti Sains Malaysia, tel. 604-6570099, fax. 04-6568417, email. This email address is being protected from spambots. You need JavaScript enabled to view it.
Corrections: A statement in the article that appeared in the New Sunday Times, May 7, 2000 implied that "fruits like bananas, mangoes, papaya and promegranates" are high in salicylates. This is incorrect; rather these fruits are examples of the exceptions.
