Case 1
A 41-year-old Caucasian woman ate approximately 150g of a superior range quiche. Within a minute she felt a tickling sensation in her throat and eyes and the latter became swollen. She became dyspnoeic with tightness of her chest, wheezing and coughing. Examination in hospital confirmed a tachycardia of 120/minute, blood pressure of 75/50mmHg and scattered wheezes throughout both lungs. She then rapidly developed widespread urticaria and further swelling of her face. Treatment with adrenaline, antihistamines and steroids produced gradual improvement over the ensuing 4 hours and she required two further injections of adrenaline.
Subsequent questioning confirmed the absence of previous atopy, concurrent use of antacids/proton pump inhibitors or non-steroidal anti-inflammatory drugs, suggestion of the oral allergy syndrome (OAS) or features to suggest a food exercise anaphylaxis. All foods eaten on the day of the reaction had been eaten before on numerous occasions without reactivity.
Skin testing was performed to include foods that may comprise undisclosed ingredients. This confirmed a very large wheal to lupin flour at 11mm but with negative responses to milk, egg, wheat, soya, sesame seed, peanuts, cod, prawn, salmon, beans, beef, pork as well as to mixed grass, tree and weed pollens. However, soon after the skin testing the patient developed tickling of her throat that responded only slowly to oral antihistamines. On return home she vomited and then improved gradually.
Her blood tests using the ImmunoCAP™ assay (Thermo Scientific, Uppsala, Sweden) later showed an isolated sensitivity to lupin flour with a specific immunoglobulin E (IgE) of 25.4kUA/L and with a total IgE of 204kU/L. There were negative responses to peanut, sesame seed and salmon as well as to 114 allergens tested in the ImmunoCAP ISAC® (Immuno Solid-phase Allergen Chip) (Thermo Scientific, Uppsala, Sweden) panel including Ara h 1. Further enquiry confirmed that the quiche contained lupin flour in the pastry crust. This was not mentioned in the list of ingredients.
Case 2
A 42-year-old Caucasian woman had three reactions over 6 years. Each was delayed by 10 minutes or more after consumption of the suspected lupin-containing food and associated with generalised urticaria and asthma but without hypotension, vomiting and diarrhoea. The first occurred with a small piece of cake in an upmarket bakery, the second occurred 3 years previously and with a small piece of bread from a health food shop and the third reaction occurred with a small amount of short crust pastry. With the latter reaction the asthma symptoms were sufficiently severe to require emergency treatment in hospital with nebulised salbutamol, intramuscular antihistamines and hydrocortisone. All the foods were later discovered to contain lupin flour as a minor ingredient. The patient denied symptoms of an underlying OAS, nut allergy, legume sensitivity and seasonal allergic rhinitis. She had mild asthma induced by exposure to animal dander and mild eczema evident with stress.
Skin prick testing confirmed an 8mm wheal to a commercial lupin flour reagent, a 4mm wheal to peanut and negative responses to soya, white bean, sesame seed and wheat. Her blood tests using the ImmunoCAP™ assay showed a total IgE of 467kU/L and she had 75kUA/L specific IgE to lupin flour with 4.04kUA/L to peanut, 9.6kUA/L to Ara h 2, 6.2kUA/L to Ara h 8, 5.4kUA/L to Bet V1, 1.61kUA/L to fenugreek and <0.1kUA/L to soya, Ara h 1 and Ara h 3.
Case 3
A 38-year-old Caucasian woman experienced immediate oral and throat itching followed, 1 hour later, by generalised urticaria and vomiting after eating pancakes and cooked cherries. There were no respiratory or cardiovascular symptoms. She had a history of atopic disease since childhood with atopic eczema, seasonal allergic rhinitis and mild asthma. She also had features of the birch pollen-related OAS, experiencing oral itching when eating raw apples, melons, hazelnut and plums.
Initial skin prick tests (SPTs) were positive to mixed grass pollens, mixed tree pollens, silver birch pollen, walnut, hazelnut and potato. However, she then had an episode of generalised urticaria 1 hour after eating gluten-free spaghetti containing lupin flour. Further SPTs were negative to raw and cooked cherries but were significantly positive with 5mm and 7mm wheals to the spaghetti containing lupin and to lupin flour extract respectively. Further investigation confirmed the pancakes to contain lupin flour also. Unfortunately she has been unable to attend for follow-up and thus further assessment of an underlying legume sensitisation has not been possible. However, she did not have any indication of legume sensitivity in her clinical history.
Case 4
A 54-year-old Caucasian woman with mild seasonal allergic rhinitis had for the previous 7 years had three to four episodes each year of unpredictable oral tingling followed by urticaria after consuming a variety of foods. The latter generally included high-end pastries and bread but without exercise, alcohol or drug ingestion. Her most recent episode had been associated with vomiting. None of the reactions had been associated with cardiorespiratory compromise or diarrhoea. Over the previous few months she had developed mild oral tingling with lentil and chickpeas but these symptoms were brief and she had continued to consume these. Skin testing confirmed a 7mm wheal to lupin flour but with negative responses to milk, wheat, peanut, white beans, soya and sesame seeds. Blood tests confirmed a mildly raised total IgE of 201kU/L with a highly positive specific IgE to lupin at 55kUA/L. The specific IgE to fenugreek was positive at 5.3kUA/L, chickpeas at 4.2kUA/L and lentil at 3.1kUA/L. The results were negative to pea, soya, whole peanut and Ara h 1. Since careful avoidance of lupin-containing foods she had not had any reactions for the previous 2 years.