Jenny Flabbee

Cross-allergenicity of peanut and lupine: the risk of lupine allergy in patients allergic to peanuts.

BACKGROUND Peanut allergy is common, but cross-allergy between legumes is rare. Proteins from Lupinus albus are increasingly eaten in the form of seeds or additives to wheat flour. The risk of cross-allergenicity is still insufficiently known. OBJECTIVE We sought to study the risk of cross-allergy to lupine in patients allergic to peanut and to study lupine allergenicity. METHODS Twenty-four patients allergic to peanuts were studied by means of skin prick tests with native lupine flour from Lupinus albus. Double-blind oral challenge tests were performed with lupine flour and peanut in 8 of these patients. Specific IgEs were assayed for peanut, lupine flour, and pollen in 6 sera. RAST inhibition tests for lupine pollen by peanut were performed on 4 of these sera. Peanut and lupine flour immunoblots were carried out for 6 sera, and crossed immunoblot inhibitions for peanut by lupine flour and lupine flour by peanut were carried out for 2 sera. RESULTS The skin prick test responses with lupine flour were positive in 11 (44%) subjects. The challenge test responses were positive in 7 of 8 subjects at the same doses as with peanut. The major lupine flour allergen (molecular mass, 43 kd) is present in peanuts. The RAST inhibition and immunoblot tests indicated cross-reactivity of peanut with the lupine flour and pollen. CONCLUSIONS The risk of crossed peanut-lupine allergy is high, contrary to the risk with other legumes. The inclusion of 10% lupine flour in wheat flour without mandatory labeling makes lupine a hidden allergen, presenting a major risk of cross-reaction in subjects already allergic to peanut products. A high sensitizing potential can also be postulated for this legume.

Allergy to quinine and tonic water

Quinine is an alkaloid extracted from cinchona bark and used principally to treat malaria. It has anti-malarial activity and is used to treat muscle cramps and influenza infections. It can also be used as an appetite stimulant and anti-asthenic agent. It is a component of several antipyretic and antalgic drugs. Quinine is also an ingredient of regularly absorbed tonic waters. Several immuno-allergic reactions have been related to quinine, among them cytopenia, hemolytic uremic syndrome, photosensitivity, hepatitis, vasculitis, and contact dermatitis [ 1,2]. Case reports of anaphylactic reactions to quinine are rare in the literature [3-51. We report here the case of a young woman who initially presented with allergy after taking a medicinal product containing quinine and who then had two episodes of anaphylactic shock after drinking a glass of tonic water containing quinine. The patient was a 20-year-old woman. She came to our hospital in 2001 for a consultation to evaluate two reactions consisting of generalized urticaria and respiratory discomfort that she related spontaneously to drinking tonic water (‘Schweppes’), a drink she did not drink regularly. In her personal health notebook there was a report of generalized urticaria, laryngeal angioedema, and a drop in blood pressure after taking CCquinil@ in 1994 for a bout of flu. The medication was contra-indicated, but no immunoallergic evaluation was performed at the time. In July 2001, 15 min after drinking a glass of ‘Schweppes’, she experienced sneezing, urticaria, respiratory discomfort, and a feeling of chest oppression, all of which