Role of nonallergic hypersensitivity reactions in children with chronic urticaria.
BACKGROUND
IgE-independent (pseudoallergic) reactions to food and food ingredients are common in a subgroup of adult patients with chronic urticaria, who have daily spontaneous occurrence of wheals. However, for children with chronic urticaria (duration longer than 6 weeks, no physical influence), no data on the importance of pseudoallergen-induced chronic urticaria are available. Therefore, we investigated the role of nonallergic hypersensitivity to food in all children seen with chronic continuous urticaria in our two clinics over the last 2 years (n = 16).


METHODS
All patients were given a low-pseudoallergen diet for 3 weeks followed by provocation with food rich in pseudoallergens. To identify the main eliciting agents, a subgroup of responders was exposed to food additives by double-blind, placebo-controlled food challenges.


RESULTS
Pseudoallergen-induced urticaria was diagnosed in 12 cases (75%). Reactions occurred mainly to coloring agents and preservatives, but also to monosodium glutamate and a sweetener (saccharin/cyclamate).


CONCLUSIONS
These results confirm that nonallergic hypersensitivity reactions play a role in children with chronic urticaria, although the latter disease is rare at that age. In children, food additives, especially coloring agents and preservatives, appear to play a more important role in eliciting nonallergic hypersensitivity reactions than in adult patients, where naturally occurring pseudoallergens in fruits and vegetables are mainly responsible.
Ehlers
I
I
Department of Dermatology, Charité, Humboldt-University Berlin, Germany.
Niggemann
B
B
Binder
C
C
Zuberbier
T
T
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D004032:Diet / Q000009:adverse effects; D004311:Double-Blind Method; D005512:Food Hypersensitivity / Q000150:complications* / Q000178:diet therapy; D006801:Humans; D007114:Immunization; D008137:Longitudinal Studies; D011446:Prospective Studies; D014581:Urticaria / Q000178:diet therapy / Q000209:etiology*