title: Mustard allergy confirmed by double-blind placebo-controlled food challenges: clinical features and cross-reactivity with mugwort pollen and plant-derived foods.
abstract: BACKGROUND
  Mustard IgE-mediated allergy is supposed to be a rare cause of food allergy, and its clinical features and cross-reactivities have not been fully elucidated.
  
  
  METHODS
  A prospective study was carried out, recruiting mustard allergic patients, and paired control subjects. A clinical questionnaire was administered, and skin-prick tests (SPT) with panels of aeroallergens and foods, serum extraction for in vitro tests and double-blind placebo-controlled food challenges (DBPCFC) were performed.
  
  
  RESULTS
  Thirty-eight mainly adult patients, with 10.5% reporting systemic anaphylaxis, were included in the study [age (mean +/- SD): 21.9 +/- 8.6 years]. DBPCFC were performed in 24 patients, being positive in 14 cases (58.3%). Patients with positive outcome showed significantly greater mustard SPT than those with negative outcome (8.2 +/- 3.7 vs 5.3 +/- 2.4 mm, P <0.05), and the receiver-operating characteristic (ROC) curve analysis yielded a cut-off value for mustard commercial SPT of 8 mm, with a specificity of 90% (95% CI, 55.5-98.3), and a sensitivity of 50% (95% CI, 23.1-76.9). A significant association between mustard hypersensitivity and mugwort pollen sensitization was found (97.4% of patients), with partial cross-reactivity demonstrated by UniCAP System inhibition assays. All patients showed sensitization to other members of Brassicaceae family, and cross-reactivity among them was also confirmed. Moreover, significant associations with nut (97.4%), leguminous (94.7%), corn (78.9%), and Rosaceae fruit (89.5%) sensitizations were also shown. Around 40% of these food sensitizations were symptomatic, including food-dependent exercise-induced anaphylaxis in six patients.
  
  
  CONCLUSIONS
  Mustard allergy is a not-uncommon disorder that can induce severe reactions. Significant associations with mugwort pollinosis and several plant-derived food allergies are demonstrated, suggesting a new mustard-mugwort allergy syndrome. A relationship between this syndrome and food-dependent exercise-induced anaphylaxis is also reported.
authors.affiliation: Hospital de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Las Palmas, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Figueroa
authors.forename: C
authors.initials: C
authors.lastname: Blanco
authors.forename: A G
authors.initials: AG
authors.lastname: Dumpiérrez
authors.forename: L
authors.initials: L
authors.lastname: Almeida
authors.forename: N
authors.initials: N
authors.lastname: Ortega
authors.forename: R
authors.initials: R
authors.lastname: Castillo
authors.forename: L
authors.initials: L
authors.lastname: Navarro
authors.forename: E
authors.initials: E
authors.lastname: Pérez
authors.forename: M D
authors.initials: MD
authors.lastname: Gallego
authors.forename: T
authors.initials: T
authors.lastname: Carrillo
mesh_terms: D000293:Adolescent; D000328:Adult; D019306:Artemisia / Q000737:chemistry / Q000276:immunology*; D001937:Brassica / Q000737:chemistry / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications / Q000175:diagnosis* / Q000276:immunology*; D005638:Fruit / Q000009:adverse effects; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D009149:Mustard Plant / Q000009:adverse effects* / Q000737:chemistry; D021184:Nut Hypersensitivity / Q000150:complications; D010936:Plant Extracts / Q000494:pharmacology; D011058:Pollen / Q000276:immunology*; D011446:Prospective Studies; D014675:Vegetables / Q000009:adverse effects
chemical_list: D010936:Plant Extracts; D007073:Immunoglobulin E