Food appears to be a triggering factor for abdominal angioedema attacks in patients with hereditary angioedema (HAE), according to new findings. In those with the rare, inherited disease triggering factors often precede an angioedema attack, though the mechanisms of these factors are not well understood.
HAE is characterized by recurrent episodes of severe swelling of the skin and mucous membranes. Typically, HAE appears on the face and around the lips but does not usually leave lasting marks. It can be serious if the swelling occurs in the throat or tongue and blocks the airway, or milder symptoms last more than a few days, according to the Mayo Clinic
In anywhere from 56% to 91% of HAE patients, factors that can trigger angioedema can include: emotions, mechanical trauma, infections and for women, hormonal changes such as menstruation, pregnancy, or intake of estrogen pills.
Previous studies have demonstrated that hypersensitivity reactions and food could be related triggers, so investigators from the University Hospital Zurich in Switzerland evaluated patients with HAE to understand the possible causes for angioedema attacks. For the study
, published in the Orphanet Journal of Rare Diseases
, patients filled in a questionnaire which asked about their date of birth, gender, and self-reported angioedema attacks linked to any food ingestion, drug administration, Hymenoptera stings, and hypersensitivity to inhaled allergens.
Each patient provided a blood sample and also received a skin prick test to test for inhaled allergens and food allergens. The investigators tested for allergies to birch, ash, grass, mugwort, Alternaria alternata
, house dust mite, cat dander, plus soy, hen's egg, cow's milk, celery, apple, codfish, shrimp, peanut, walnut, curry, chili, rye flour, and wheat flour. If the patients had any hypersensitivity with angioedema, the investigators also performed a serological ImmunoCAP test.
The analysis included 27 women and 15 men, of which 79% stated trigger factors, the investigators report. About one-third of those factors were suspected foods linked to abdominal angioedema, such as tomato, green salad, fish, citrus fruits, apples, onion, garlic, cheese, chili, kiwi, milk, tree nuts, strawberry, pineapple, shrimps, bread, banana, leek, chicken, and alcohol. However, neither the skin prick test nor the ImmunoCAP test turned out positive for any of the food allergens tested.
"Patients suffering from hereditary angioedema always should be asked for possible trigger factors including possible food," study author Dr Urs S. Steiner, from the department of Clinical Immunology at University Hospital Zurich, told Rare Disease Report®
. "If patients suffer from food-induced angioedemas, food allergies have to be excluded, but must often an intolerance reaction and not allergy is inducing the angioedema attack in these people."
However, the most frequent trigger—seen in 18 women and 8 men—was emotion, followed by trauma, then food. Two women each were triggered by drugs and Hymenoptera stings.
The most prevalent allergen sources were grass and tree pollen, followed by house dust mites, cat dander, and mugwort, the investigators write. Rhinoconjunctivitis caused symptoms in 10 of the 12 sensitized patients. There was no difference in the incidence of hereditary angioedema attacks in atopic and non-atopic subjects.
The study authors also wrote that their findings were aligned with the current published literature. They pointed out that histamines released from foods such as cheese, alcohol, fish, tomatoes, strawberries, pineapples, nuts, citrus fruits, and kiwis could be linked to the triggering of angioedema attacks. However, they said, there has not been a reliable laboratory test for diagnosing histamine intolerance.
Despite the small sample size, the investigators still consider the results valid; however, they did admit that self-reporting trigger factors could carry a reporting bias from the patients.
“Studying trigger factors in hereditary angioedema is essential to obtain a better understanding of the disease mechanisms,” the study authors concluded.