Rhinoconjunctivitis induced by exposure to Swiss chard

Abstract

RATIONALE: Food allergy is common, although allergic symptoms can sometimes be produced by skin contact or inhalation of volatile food antigens. Exposure to these allergens is also relatively common in nonoccupationally settings, such as the home. We present a case of food allergy to Swiss chard. METHODS: Total and specific IgE (sIgE) were determined by ImmunoCAPÒ and ImmunoCAPÒ ISAC 112. Skin prick tests, SDS-PAGE and Immunoblotting with extract of leaf and stem of Swiss chard were carried out. Protein sequencing was analysed by mass spectrometry. RESULTS: Prick were positive to extracts from D. pteronyssinus, dog epithelium, pollens from P. pratense, P. lanceolata and O. europaea, spinach, carrot and chard. Prick by prick with cooked and raw chard and apple peel were also positive. Total IgE: 222 kU/L. sIgE to apple, Mal d 1 and chard were negative. ImmunoCAP ISAC 112 was positive for rPhl p 1 and 2 and nOle e 1. By means of SDS-PAGE and Immunoblotting we detected IgE binding bands about 55 kDa, 27 kDa and 20 kDa in leaf Chard extract and about 37 kDa and 30 kDa in stem Chard extract. In the apple extract two IgE binding bands about 70 kDa and 30 kDa were observed. CONCLUSIONS: We present a patient with allergy to Swiss chard and tomato. IgE binding bands are detected around 20 kDa.To our knowledge, this is the first report to identify a new allergen in raw Swiss-chard extract.Abstracts AB75 SATURDAY