The risk of systemic reactions to skin prick-tests using food allergens: CICBAA data and literature review.

Prick-tests to foods are usually carried out as the first step in the diagnosis of food allergy. Severe anaphylaxis accounts for 4.9 % of allergies in children and occurs more frequently in adults, raising the possibility of systemic reactions to prick-tests in highly sensitized people. Several studies published in the literature have used commercial extracts. As for airborne allergens, concentrations causing a skin reaction of 15 mm do not present a risk of systemic reactions. Prick-tests to native foods--prick-in-prick tests--have been less extensively studied. The CICBAA1 data, from 1,138 food allergic patients of all ages, cover 34,905 prick-in-prick tests to foods. The wheal of these prick-tests has been regulary registered. The risk of systemic reactions can be evaluated at 0.008 %. There were no severe reactions and anti-histamine and corticosteroid therapy were sufficient. These results are similar to those of the large study in 2000 carried out by Devenney in neonates (0.005%). A review of the literature reveals only a few severe reactions in adults. The authors draw attention to the necessary precautions: temporary contra-indication for skin prick-tests in children and adults with grade 3 or 4 asthma, with particular attention to such foods as all kinds of nuts, fish, etc.

Food allergy and IgE sensitization caused by spices: CICBAA data (based on 589 cases of food allergy).

BACKGROUND: Spices originate in various botanical families: Apiaceae, Lamiaceae, Lauraceae, Leguminosae, Liliaceae, Myristicaceae, Myrtaceae, Piperaceae, Solanaceae, Zingiberaceae.... METHODOLOGY: Prick-tests to native spices have been carried out in patients suspected of food allergies to spices. The CICBAA data bank includes 589 cases of food allergies, a part of which has benefited from investigations for spices. Data about the rate of sensitization and food allergy are available. RESULTS: Frequent sensitization to Apiaceae is observed: coriander, caraway, fennel, celery: 32% of prick-tests in children, 23% of prick-tests in adults. Sensitization to Liliaceae: garlic, onion, chive, is observed in 4.6% of prick-tests in children, 7.7% of prick-tests in adults. Rare cases of sensitization to paprika and saffron are recorded. Prick-tests to nutmeg, ginger and clove are currently negative. 10 food allergies related to the mugwort-celery-spices syndrome are reported: coriander: 1, caraway: 2, fennel: 3, garlic: 3, onion: 1. Food allergy to spices is unfrequent: 2% of the totality of food allergies. However, only adults are allergic to spices and allergy to spices accounts for 6.4% of food allergies in adults. Tiny amount of proteins are usually ingested. Patients at risk of spice allergy are young adults sensitized to mugwort and birch allergens, sharing cross-sensitization with various food vegetal allergens. The clinical suspicion raises from frequent post-prandial systemic reactions. Other allergens of vegetal origin have to be cleared. Diagnosis can be established by DBPCFC using powdered spices in capsules.