Lesson of the week: Horse allergy in children

Abstract

Horse dander may be the “hidden” allergen responsible for a child's asthma Allergy to pets, such as cats and dogs, causes significant morbidity in children.1 Apart from immediate symptoms of hypersensitivity, allergens from pets are associated with chronic childhood asthma.1 2 Clinicians are less familiar with horse allergy. Our clinical experience suggests that it is an important problem, even in an urban environment. Despite a lack of obvious exposure to horse dander this allergen may be responsible for a child's asthma. We present three of the 28 cases of horse allergy seen recently in our clinic. Peak expiratory flow in nine year old boy exposed to horse dander from his sister's riding gear. Lung function deteriorated each weekend apart from one his sister spent away. Once his sister gave up riding, variability in peak flow disappeared, with no dips below 200/min Case 1 —Within minutes of riding a pony at a fete, an eight year old boy developed angio-oedema and respiratory distress. On initial assessment in the accident and emergency department, he was tachypnoeic with a saturation of 90% in air. He improved after treatment with oxygen, nebulised salbutamol, intravenous hydrocortisone, and intravenous chlorpheniramine. Skin prick testing produced a 6 mm weal to horse dander and a 3 mm weal to house dust mite (positive histamine control, 3 mm). He was advised to avoid horses, to carry chlorpheniramine in case of accidental exposure, and to use inhaled salbutamol and intramuscular adrenaline in the event of respiratory symptoms. Case …