Vital signs
Apples and pears can trigger asthma, Austrian researchers have found. They point out in the Journal of Allergy and Clinical Immunology that these fruits, together with certain vegetables such as carrots, potatoes, celery and nuts, all carry proteins similar to birch pollen allergens. Patients with a known birch pollen allergy might be vulnerable, they warn.

Paediatricians at the Royal Hospital for Sick Children, Glasgow, meanwhile, say that parents are failing to ensure that children with asthma get sufficient relief from inhalers. In a study involving 22 pre-school children published in the British Medical Journal, they found that on average parents used the child's bronchodilator on only 63 per cent of days when they had asthmatic symptoms.