EDUCATION REDUCES INCIDENCE, SEVERITY OF NUT ALLERGIES

CAMBRIDGE, ENGLAND—A simple management plan can help reduce both the incidence and severity of potentially fatal allergic reactions to peanuts and other nuts, a British study suggests.[1] Nut allergies are common and often life threatening, yet few patients are taught adequate preventive strategies, said Pamela Ewan, MD, Director of the Department of Allergy and Clinical Immunology at Addenbrooke’s Hospital in Cambridge, England.

“Simply telling patients to avoid nuts or prescribing an EpiPen alone is not enough. You need a good management system consisting of detailed advice on nut avoidance combined with medication, a written treatment plan, and training in the use of medication,” Dr. Ewan said in an interview with RESPIRATORY REVIEWS. “This approach is effective in reducing both the incidence and severity of recurrent reactions. But, it’s important to reinforce the advice. Giving the advice once is inadequate,” she added.

Dr. Ewan and her associate, A.T. Clark, MD, developed and assessed a management program to help patients prevent and manage recurrent allergic reactions to nuts. Study subjects included unselected referrals with confirmed peanut or tree-nut allergy. From each patient, the authors obtained a detailed history of all such reactions, and the index reaction (the one that brought the patient in for treatment at study enrollment) was graded as mild, moderate, or severe. A reaction was considered moderate if it included mild laryngeal edema; severe reactions were defined as those that included pronounced dyspnea or hypotensive symptoms. All other reactions were considered mild.

Emergency medications, including oral antihistamines with or without inhaled or injected epinephrine, were prescribed according to the severity of nut allergy. Patients, parents, and school staff received verbal and written suggestions on nut avoidance, training in recognition and treatment of reactions, and a written treatment plan.

Subjects included 567 patients (ages 4 months to 55 years) with a median age at onset of nut allergy of 3 years and a median age at presentation of 7.5 years. Index reactions were mild in 277 patients, moderate in 191, and severe in 71.

FOLLOW-UP REACTIONS WERE LESS SEVERE

During the study, 88 patients (15.5%) had follow-up reactions; 62 of these were mild. Twenty-three patients had moderate reactions. Only three patients, all of whom were older than age 20 years, had severe reactions. Most of the patients who had had moderate or severe index reactions had either no recurrent reaction or a less severe recurrence.

Epinephrine injections had not been given to 172 patients because they were not thought to be at risk of a severe recurrent reaction. Only two of these patients suffered moderate reactions (which were controlled with inhaled epinephrine), and only one had a severe reaction.

Snacks were the primary source of the nuts that caused follow-up reactions; more severe reactions usually followed meals. The authors were not surprised to find that the severity of the recurrent reaction was related to the amount of nut ingested.

Although the findings are encouraging, Dr. Ewan believes that a better understanding of the natural history of nut allergy is needed. “Until we know this, it’s difficult to be absolutely sure about the best management approach,” she said.

--Deborah L. O’Connor

Reference
1. Ewan PW, Clark AT. Long-term prospective observational study of patients with peanut and nut allergy after participation in a management plan. Lancet. 2001;357:111-115.