title: Diagnostic approach for suspected pseudoallergic reaction to food ingredients.
abstract: Chronic urticaria, recurrent angioedema and non-allergic asthma have all been associated with pseudoallergic reactions to food ingredients. For atopic dermatitis and diseases of the gastrointestinal tract, this association is controversial. Pseudoallergic reactions can be elicited by additives as well as by natural food ingredients. An altered histamine metabolism may be associated with pseudoallergy. Acute urticaria or a short episode of angioedema is not an indication for exhaustive evaluation. If basic diagnostic screening is negative in chronic urticaria, a low-pseudoallergen diet can be considered. Skin and serological tests are not objective diagnostic parameters for pseudoallergic reactions. The severity of symptoms should be documented while the patient is on a low-pseudoaller-gen diet. Oral provocation with additives leads to reproducible symptoms only in a few cases. Therefore, if a low-pseudoallergen diet brings improvement, the patient is then exposed to a pseudoallergen-rich "super meal". After a positive reaction to the "super meal" the challenge with additives takes place in the form of collective group exposition. When the patient has asthma or a history of anaphylac-toid reactions, testing with individual substances in carefully increasing dosages is required. The suspicion of adverse reactions against histamine can be confirmed by a challenge with histamine dihydrochloride. In the case of respiratory symptoms, provocation by inhalation should be considered. Objectifying symptoms especially in gastrointestinal diseases is mandatory and should include double-blind placebo-controlled food challenge, if possible.
authors.affiliation: info@ernaehrung-allergologie.de
authors.forename: Imke
authors.initials: I
authors.lastname: Reese
authors.forename: Torsten
authors.initials: T
authors.lastname: Zuberbier
authors.forename: Britta
authors.initials: B
authors.lastname: Bunselmeyer
authors.forename: Stephan
authors.initials: S
authors.lastname: Erdmann
authors.forename: Margot
authors.initials: M
authors.lastname: Henzgen
authors.forename: Thomas
authors.initials: T
authors.lastname: Fuchs
authors.forename: Lothar
authors.initials: L
authors.lastname: Jäger
authors.forename: Jörg
authors.initials: J
authors.lastname: Kleine-Tebbe
authors.forename: Ute
authors.initials: U
authors.lastname: Lepp
authors.forename: Bodo
authors.initials: B
authors.lastname: Niggemann
authors.forename: Martin
authors.initials: M
authors.lastname: Raithel
authors.forename: Joachim
authors.initials: J
authors.lastname: Saloga
authors.forename: Stephan
authors.initials: S
authors.lastname: Vieths
authors.forename: Thomas
authors.initials: T
authors.lastname: Werfel
mesh_terms: D003876:Dermatitis, Atopic / Q000175:diagnosis* / Q000209:etiology; D005502:Food / Q000009:adverse effects*; D005512:Food Hypersensitivity / Q000175:diagnosis*; D005767:Gastrointestinal Diseases / Q000175:diagnosis* / Q000209:etiology; D005858:Germany; D006801:Humans; D017410:Practice Guidelines as Topic; D012882:Skin Tests / Q000379:methods / Q000592:standards*; D014581:Urticaria / Q000175:diagnosis* / Q000209:etiology