Skin-prick test of asthmatics 'useful' GP tool

By ANGELA GREGORY health reporter

Routine skin prick testing of asthmatics by doctors to identify allergies has been recommended to help patients cope with the debilitating condition.

A study published in the New Zealand Medical Journal says skin prick testing is an inexpensive and useful tool by which doctors could identify allergies that might contribute to their patient's asthma.

The research author, Dr Isobel Martin, said skin-prick tests were practical and feasible, but rarely offered in general practice.

A senior lecturer at Dunedin Medical School, Dr Martin said 9 per cent of the New Zealand adult population took regular medication to control asthma symptoms.

Asthma was a considerable economic and social burden to the individuals with it and to society in terms of direct, indirect and intangible costs.

Numerous asthma guidelines and management protocols had been developed in the past decade.

They provided details on diagnosis, treatment and management, including self-management.

"They recommend the assessment of allergic status and advocate allergen avoidance as an integral part of the management of allergic asthma," she said.

But many patients were confused and health workers were not clear about the value of allergen recognition and avoidance.

Many asthmatics had only partial knowledge, and some had no awareness, of any specific allergic triggers. Anecdotal evidence suggested some families were using extensive allergen avoidance strategies without first identifying the allergies.

It would be helpful for patients to know to what they were allergic, so that they could use simple and appropriate avoidance, Dr Martin said.

The simplest method of determining specific allergic sensitivity was by skin prick testing.

A small number of studies had already shown a clinical benefit from reducing allergens.

Asthma NZ president Dr Allen Liang said doctors should be paying more attention to allergies in relation to asthma, because they played a big role in its onset in children.

Dr Liang said allergies were regarded with suspicion until their scientific basis was established in 1976, but medical attitudes still lagged behind.

Medical students needed more training on allergies, he said.

Dr Liang said allergen testing was not as straightforward as suggested.

Both skin pricks and blood tests were needed to establish the allergen and the severity of its effect, and the interpretation needed "expertise".

He also said hair testing, where people sent head hair overseas for allergen testing, was hogwash.

The Royal College of GPs president, Dr Helen Rodenburg, said doctors would consider allergies in asthma patients along with other indicators.

Sometimes the type of allergy was obvious and would not require testing, she said.

There was also a problem in not all regions having convenient access to diagnostic laboratories able to carry out the time-consuming testing.

Further reading
nzherald.co.nz/health