What is adult onset asthma?

Adult onset asthma generally refers to the onset of asthma for the first time in an adult. People who are or have been smokers may need further investigation as the symptoms of asthma, such as breathlessness, wheeze and cough, can be similar to those of smoking related illnesses. In all cases, not smoking and avoiding secondhand smoke is advised. For adult onset asthma, preventive medication is usually prescribed long term to help maintain lung function.

Can asthma in adults be due to a recurrence of childhood illness?

Yes. In some cases, childhood asthma persists throughout adult life. In other cases childhood asthma may disappear for many years, but return as adult onset asthma. Sometimes childhood symptoms may not have been diagnosed as asthma; they may have been called recurrent bronchitis or wheezy bronchitis.

Is adult onset asthma due to smoking?

No. Tobacco smoking causes chronic obstructive pulmonary disease (COPD). COPD also causes breathlessness, cough and sometimes wheeze. Because of the similarity of symptoms, doctors cannot always be sure about whether someone who has smoked has a smoking-related illness or adult onset asthma. A spirometry test may help to determine the diagnosis.

What causes adult onset asthma?

The cause of asthma at any age remains uncertain. We do not understand why symptoms develop at a certain age, or why they might disappear.

Avoid asthma triggers

Adult onset asthma can be made worse by trigger factors similar to those in childhood asthma. The first priority is to avoid trigger factors such as:

• Tobacco smoke - your breathing difficulties are more likely to get worse sooner and permanently if you smoke or are exposed to environmental tobacco smoke - also see Smoking and asthma
• Dusts - dust can irritate the nose, throat and lungs. With asthma it is best to avoid dusty occupations such as baking, woodwork, metal foundry work, mining, etc.
• Allergens - some indoor allergen sources such as cats, mould on walls, or dust, make asthma worse and should be avoided wherever possible. Other allergens, such as household dust mite, are more difficult to avoid. You should make every effort to keep your home and workplace as free of your asthma trigger factors as possible.
• Fumes and strong odours can make asthma worse. If you find that some household cleaners trigger your asthma, you should try to avoid this product and use an alternative. Industrial processes may be a cause or trigger of asthma. Spray paint fumes from panel-beating works, for instance, are a recognised asthma trigger.
• Infections - colds and upper respiratory tract infections are the infections that most commonly make asthma worse, and cannot be easily prevented. Influenza vaccination will not prevent most ordinary colds; however, flu vaccination is advised for people with chronic respiratory conditions to reduce the risk of influenza.
• Medications - beta-blockers are used for treating high blood pressure and associated angina. Beta-blockers are also contained in some eye drops used to treat glaucoma. You should not use these medicines if you have asthma - they can make it worse. Aspirin and pain relievers called 'non-steroidal anti-inflammatory drugs' (NSAIDs) can also make asthma worse. Also see Asthma and other medicines
• Foods - if you are sensitive to foods such as nuts or seafood and food additives (eg, sulphites 220 - 228) used as preservatives in food and drinks, you should avoid these. Milk or dairy products rarely trigger asthma.

Could it be something else?

Sometimes other illnesses seen in adults may seem like adult onset asthma, eg, heart disease which causes fluid retention, difficulty breathing and wheezing. For this reason adult onset asthma can be difficult to diagnose.

Will adult onset asthma ever go away?

Adult onset asthma is usually persistent and permanent. Medications are usually needed continuously to help keep adult onset asthma under control.

Everybody's lung function decreases in middle age. However, if your asthma is under-treated, there is a risk that your lung function may deteriorate quickly and may never recover. You should, therefore, use regular medication in order to protect your lung function, rather than risking permanent lung damage. Smoking is likely to cause a faster rate of deterioration of lung function.

Is the treatment different from childhood asthma?

The main principles are similar. The key issue is to maintain best lung function at all times. Because adult onset asthma often causes long-term symptoms, you will usually be prescribed preventive medication. This is to prevent permanent impairment of your lung function.

Related topics

Also see What is asthma? and Asthma medicines and Keeping asthma under control

Original material provided by the Asthma Foundation of New Zealand, 2010. Edited by everybody, December 2010.