Case Studies

 Case 4.8 Nut allergy

A 15-year-old schoolgirl was admitted to hospital as an emergency whilst on holiday. Her parents believed her to be allergic to nuts. At the age of 5 years, she vomited about 1min after eating a bar of chocolate containing nuts. Three years later, she developed marked angioedema of her face, lips and tongue, followed by tightness of her throat and vomiting: this occurred 2-3min after friends of her brother decided to test her allergic status by pushing peanuts into her mouth and holding her jaws shut! Less severe attacks had followed inadvertant ingestion of hazelnuts and almonds. As a consequence, she avoided peanuts and treenuts wherever possible.

The emergency admission occurred following a single lick of a vanilla ice cream. Within seconds, she developed angioedema of her lips and tongue, difficulty in breathing and felt light-headed. Following an emergency call, she was injected with intramuscular adrenaline and intravenous hydrocortisone by the paramedical service, and admitted to hospital overnight. She made a rapid and uneventful recovery. Her parents later recalled that one ice-cream scoop was used by the vendor to dispense all flavours: the customer immediately in front of the patient had been served a nut-flavoured ice cream.

On investigation, she had a grade 6 RAST (see Chapter 19) to peanut with significant but lesser (grade 2) reactivity to hazelnut, almonds and brazil nuts. She was also atopic, with strongly positive RASTs to grass pollen (grade 4) and cat dander (grade 3).

The management of her nut allergy comprised advice on strict avoidance of peanuts and tree nuts, with particular attention to 'hidden' nuts in food. She was advised to wear a medical alert bracelet as a warning to emergency personnel of a possible cause of sudden collapse, and to carry with her at all times a self-injectable form of adrenaline. There is no place for hyposensitization in peanut-allergic patients.