Asthma

Asthma has been extensively researched, written about and debated over the last few decades. There is much evidence to suggest that the incidence is, in line with food allergies, allergic rhinitis (hay fever) and atopic dermatitis (eczema), increasing. For an excellent yet brief, overview on asthma, including symptoms, triggers, diagnosis and treatment please follow the link, http://www.allergyuk.org/fs_asthma.aspx. This article is adult patient oriented and therefore, a few additional remarks specific for children need to be mentioned.

Cough Variant Asthma

The majority of children with asthma will have symptoms of difficulty in breathing, usually manifest as wheezing, a higher pitched whistling sound more noticeable during exhalation. There are however a small number of children who will have only cough as a symptom of asthma, i.e with no or insubstantial wheezing. This can be prolonged, recurrent, usually ‘dry’ but can be ‘fruity’, and often prevents the child (and their parents!) from sleeping. This can be ‘cough variant asthma’, especially if it occurs on the background of personal or family history of allergic disorders. There is no full proof diagnostic test to confirm or exclude (see next section on diagnosis) this condition. Other causes of chronic cough, e.g recurrent viral infection, cystic fibrosis and protracted bacterial bronchitis, need to be excluded.

Diagnosis

Spirometry, specialised lung function tests and repeated measurements of peak flow rates (PFR) can help in the diagnosis of asthma in adults and older children, usually more than 6 yrs. For children under 5 yrs, when there is the most anxiety amongst parents regarding a possible diagnosis of asthma in their child, there are no diagnostic tests for available. Paediatricians would normally rely on: their clinical experience; possible use of allergy tests; and the child’s personal history of- food allergies, allergic rhinitis (hay fever) and atopic dermatitis (eczema); family history of allergic disorders and possibly a chest x ray to arrive at a possible diagnosis. In many cases even this is not conclusive and a tentative diagnosis is made on responsiveness to reliever inhalers (e.g salbutamol) or short courses of inhaled steroids (e.g beclometasone).

Use of inhalers

When treatment is contemplated in children with asthma, apart from occasional use of syrups, tabs and injectable devices, most of treatment is based on judicious use of inhalational devices. There are many inhalation devices available; broadly speaking these can be divided into aerosol or powder based. Efficient use of aerosol devices (MDIs) can be improved by the correct use of additional devices, e.g volumatic or aerochamber and even auto-triggered devices. It is essential, especially in infants and children, that the correct combination and technique of use of inhalers with/ without spacer devices are used to provide optimal response.