Portal de Periódicos da CAPES

Banana anaphylaxis with a negative commercial skin test

2004; Elsevier BV; Volume: 115; Issue: 3 Linguagem: Inglês

10.1016/j.jaci.2004.10.034

1097-6825

David W. Hauswirth, A. Wesley Burks,

Contact Dermatitis and Allergies

To the Editor: The diagnosis of food allergy is becoming increasingly complex, but the skin prick test (SPT) is still at the center of the diagnostic work-up. Often the diagnosis of food allergy is based on skin tests alone. Fresh fruit, whether implicated in anaphylaxis or the oral allergy syndrome (OAS), poses many problems for traditional skin testing. As Ortolani et al1Ortolani C. Ispano M. Pastorello E.A. Ansaloni R. Magri G.C. Comparison of results of skin prick tests (with fresh foods and commercial food extracts) and RAST in 100 patients with oral allergy syndrome.J Allergy Clin Immunol. 1989; 83: 683-690Abstract Full Text PDF PubMed Scopus (393) Google Scholar first reported in 1989, there is significant variability in the response to commercial extracts and fresh fruit applied by the prick-prick method. Other investigators have reported similar findings in food-induced anaphylaxis as well as OAS.2Rosen J.P. Selcow J.E. Mendelson L.M. Grodofsky M.P. Factor J.M. Sampson H.A. Skin testing with natural foods in patients suspected of having food allergies: is it a necessity?.J Allergy Clin Immunol. 1994; 93: 1068-1070Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar SPT has been compared with food challenge for the diagnosis of food allergy. In one study,3Rance F. Juchet A. Bremont F. Dutau G. Correlations between skin prick tests using commercial extracts and fresh foods, specific IgE, and food challenges.Allergy. 1997; 52: 1031-1035Crossref PubMed Scopus (172) Google Scholar only 58.8% of patients with a positive challenge had a positive commercial skin test result. However, 91.7% of patients with a positive challenge had a positive skin test result with fresh food.3Rance F. Juchet A. Bremont F. Dutau G. Correlations between skin prick tests using commercial extracts and fresh foods, specific IgE, and food challenges.Allergy. 1997; 52: 1031-1035Crossref PubMed Scopus (172) Google Scholar Because of the increasing association of banana allergy and latex allergy, the major allergens in banana have been characterized.4Sanchez-Monge R. Blanco C. Diaz-Perales A. Collada C. Carrillo T. Aragoncillo C. et al.Isolation and characterization of major banana allergens: identification as fruit class I chitinases.Clin Exp Allergy. 1999; 29: 673-680Crossref PubMed Scopus (93) Google Scholar Patients not allergic to latex have been confirmed to have anaphylaxis to banana.5Grob M. Reindl J. Vieths S. Wuthrich B. Ballmer-Weber B.K. Heterogeneity of banana allergy: characterization of allergens in banana-allergic patients.Ann Allergy Asthma Immunol. 2002; 89: 513-516Abstract Full Text PDF PubMed Scopus (33) Google Scholar The major allergens are 32-kd and 34-kd proteins that have class I chitinase activity.4Sanchez-Monge R. Blanco C. Diaz-Perales A. Collada C. Carrillo T. Aragoncillo C. et al.Isolation and characterization of major banana allergens: identification as fruit class I chitinases.Clin Exp Allergy. 1999; 29: 673-680Crossref PubMed Scopus (93) Google Scholar More than half of patients allergic to banana respond to SPT performed with 1 of these 2 isolated proteins.4Sanchez-Monge R. Blanco C. Diaz-Perales A. Collada C. Carrillo T. Aragoncillo C. et al.Isolation and characterization of major banana allergens: identification as fruit class I chitinases.Clin Exp Allergy. 1999; 29: 673-680Crossref PubMed Scopus (93) Google Scholar Here, we report the case of a young boy with systemic symptoms and negative SPT result to commercial extract. This case is important because it is one of the first reported pediatric cases of systemic anaphylaxis to banana. Banana is generally thought to have low allergenic potential and is often appropriately introduced as part of the early infant diet. As food allergy becomes more prevalent, foods once believed not to cause systemic symptoms will increasingly require more in-depth clinical evaluation. A 7-month-old boy presented to the allergy and immunology clinic at Duke University for evaluation of atopic dermatitis and possible food allergy. His atopic dermatitis started in the first several months of life. At 3 months of age, he had angioedema and erythema on his face and neck on his first introduction to a cow's milk formula. He was exclusively breast-fed until this point. At 5 to 6 months of age, he was started on solid foods. Approximately 2 hours after an isolated feeding of crushed banana, he awoke from a nap with generalized urticaria, vomiting, and respiratory symptoms, including wheezing. He was immediately taken to the emergency room for appropriate treatment. He had been fed banana on one previous occasion, several weeks before this ingestion, without symptoms. He had no history of reaction to substances that cross-react with banana, including latex. At the time of his initial evaluation in our clinic, he had a normal physical examination except for moderate atopic dermatitis. Initial SPT result with a commercial milk extract was positive. The SPT result with commercial banana extract (Greer Laboratories, Lenoir, NC) was negative, histamine control was 4+, and saline was not reactive. Because of his convincing history, a prick-prick test with fresh banana was performed, resulting in a 20-mm × 20-mm wheal. We used a Greerpick (Greer Laboratories, Lenoir, NC), first puncturing a peeled banana and then, with the same pick, placing the skin test in the usual fashion. Further testing included a CAP-FEIA (Pharmacia, Uppsala, Sweden) to banana, with a level of 4.70 kU/L. For banana, specific IgE levels predictive of clinical reactivity have not been established. However, 2 patients with food challenge–confirmed systemic symptoms or OAS had values of 5.21 kU/L and 5.24 kU/L.5Grob M. Reindl J. Vieths S. Wuthrich B. Ballmer-Weber B.K. Heterogeneity of banana allergy: characterization of allergens in banana-allergic patients.Ann Allergy Asthma Immunol. 2002; 89: 513-516Abstract Full Text PDF PubMed Scopus (33) Google Scholar Our patient was sent home on a food-avoidance diet, with injectable epinephrine for use in case of an accidental ingestion. Despite occasional clinical cross-reactivity, we did not recommend avoidance of latex or other foods (kiwi, avocado, figs) or further testing. This patient's case illustrates one of the pitfalls in the evaluation of fruit allergy. Commercial extracts for food and fruit testing are not standardized. Akkerdaas et al6Akkerdaas J.H. Wensing M. Knulst A.C. Krebitz M. Breiteneder H. de Vries S. et al.How accurate and safe is the diagnosis of hazelnut allergy by means of commercial skin prick test reagents?.Int Arch Allergy Immunol. 2003; 132: 132-140Crossref PubMed Scopus (67) Google Scholar found significant variation in the protein concentration of 9 commercially available hazelnut extracts for SPT. One can infer that all nonstandardized extracts have similar, if not greater, variability. The use of prick-prick skin testing was used as part of a large study of melon allergy and found to have a sensitivity of 79% (54%-93%).7Rodriguez J. Crespo J.F. Burks W. Rivas-Plata C. Fernandez-Anaya S. Vives R. et al.Randomized, double-blind, crossover challenge study in 53 subjects reporting adverse reactions to melon (Cucumis melo).J Allergy Clin Immunol. 2000; 106: 968-972Abstract Full Text Full Text PDF PubMed Scopus (69) Google Scholar Many clinicians are using SPT with fruit extracts as a method to diagnose food allergy. On the basis of food challenge data,8Sampson H.A. Comparative study of commercial food antigen extracts for the diagnosis of food hypersensitivity.J Allergy Clin Immunol. 1988; 82: 718-726Abstract Full Text PDF PubMed Scopus (105) Google Scholar the presumed negative predictive value of a nonreactive skin test is greater than 95%. Our case illustrates that fresh fruit–induced anaphylaxis may be missed if commercial extracts alone are relied on for diagnosis in the setting of a suggestive clinical history. Prick-prick testing with fresh fruit is a quick and inexpensive method to increase the diagnostic yield of SPT. Any patient with a convincing history and negative commercial extract SPT should have prick-prick testing. In addition, CAP-FEIA RAST testing and oral food challenge should be part of the complete evaluation.