Basophil activation test in the diagnosis of sulphite‐induced immediate urticaria

Abstract

We have read the interesting review on the clinical effects of sulphite additives recently published in the journal [1]. Sulphite hypersensitivity, particularly when manifesting mainly with cutaneous symptoms, remains a dark area of diagnosis where work-up and outcomes are frequently unclear. In this respect, here we describe a case that may help in the diagnostic work-up of patients claiming sulphite allergy.A 56-year-old non-smoking, non-asthmatic mechanic with no history of allergy, living in a vineyard area on the Mediterranean coast reported that 3 years before he had started to suffer bilateral ear pruritus, conjunctival redness, facial rash, lip angioedema and sometimes generalized urticaria after drinking local wines purchased directly from local cellars. As a consequence, he switched to bottled brands, but the process continued, extending later to some processed meats, although he was able to eat nonprocessed beef and pork. Baseline spirometry was normal, and bronchodilator test was negative. Standard prick tests with inhalant allergens and latex were negative. An extended battery of 34 food skin tests, including different kinds of grapes, as well as 18 spices used in food industry, were negative. A skin prick test with 10 mg/mL sodium metabisulphite in saline proved negative. A double-blind placebo-controlled sulphite provocation test with sodium metabisulphite showed ear and facial itching, neck redness and two large retroauricular hives 25 mm in diameter after the 10 mg metabisulphite dose. Spirometry at baseline and at the end of the tests was unchanged. A basophil activation test (BAT), performed using 5.21 and 20.8 mg/ mL of sodium metabisulphite, yielded a strongly positive result (stimulation index: 8.8). The patient was therefore diagnosed of sulphite sensitivity and instructed to avoid eating manufactured foods, which could contain sulphites as additives, as well as wine. After 6 months, he has not suffered further episodes of itching or urticaria.Although immediate cutaneous sulphite hypersensitivity has long been known [2, 3], it is rare to find proven cases in daily practice, with most patients suffering chronic urticaria and reporting inconsistent and varying symptoms that are invariably attributed to industrial foods or 'additives' and which can seldom or never be proved with objective tests [4]. Nevertheless, some cases of sulphite sensitivity leading to recurrent urticaria or anaphylaxis may occur that merit investigation and accurate diagnosis [3, 5]. The BAT and a placebo-controlled challenge test can help to identify sulphites as the culprit substance in some of these patients and allow them to avoid potentially harmful foods by simply reading labels or asking about composition. References1 Vally H, Misso NLA, Madan V. Clinical effects of sulphite additives.

Basophil Activation Test with Food Additives in Chronic Urticaria Patients

“…Garcia-Ortega and his colleagues confirmed using the BAT that hypersensitivity to sodium metabisulfite induced CU [52]. Ebo et al reported the case of a patient who had a history of recurrent anaphylaxis after eating cheese, and found that hypersensitivity to the natural dye annatto (Ceska Annato WS E160b), which was positive on the BAT, was the cause of anaphylaxis [53].…”

Sodium metabisulfite hypersensitivity in urticaria

“…We noticed that urticarial symptoms were relatively more severe in the MBS PT (+) patients and lasted longer than in the rest. Similarly to other studies [7,11], we determined that the patients with sulfite contact allergies may also have shown symptoms after their ingestion and that patch tests may be useful to diagnose immediate reactions to sulfite-containing foods [7,20].…”

“…Several mechanisms are thought to play a role in the observed sulfites hypersensitivity, but IgE mediated reactions have rarely been documented so far [11,27,28].…”

“…The hypersensitivity symptoms described after sulfites ingestion may include rhinitis [7], asthma [6,[8][9][10], urticaria [11][12][13], systemic rash [14][15][16], intestinal disorders, dizziness [7], headache [17], and anaphylaxis [7,[18][19][20]. Sulfites are thought to be the main food additive exacerbating asthma, which affects 3-10% of the population [20].…”

Selective and Sensitive Chromofluorogenic Detection of the Sulfite Anion in Water Using Hydrophobic Hybrid Organic–Inorganic Silica Nanoparticles

“…[1] However, several studies had associated topical, oral, or parenteral exposure to high doses of sulfite with adverse reactions as dermatitis, urticaria, flushing, hypotension, abdominal pain, and diarrhoea. [2] In fact, several reports confirmed that some people can be extremely sensitive even to very low sulfite levels [3] and that bronchoconstriction can occur in many asthmatic patients [4] or in people exposed to high doses. [5] Exposure to high doses of sulfite can occur for consumption of food and drinks that contain this additive (as fruits, vegetables, salads, meat, gelatine, juices, vinegar, soft drinks, beer, wine, and others), through the use of several drugs (adrenaline, phenylephrine, corticosteroids, and local anaesthetics), some cosmetics (hair colors and bleaches, creams, and perfumes) or in some occupational settings (leather, textile, mineral, pulp, rubber, agriculture, and chemical industries).…”