Pickled onions may trigger asthma attacks

[Guest guest]

I found this old abstract, which says that pickled onions can trigger asthma

attacks in

some persons if the onions are sufficiently rich in sulphur. Sensitivity to

sulfites can vary

from person to person.

Now, this raises some open questions :

1) in the case of sensitivity to pickled onions, are asthma attacks due only to

sulphur, to

the pickling liquid (vinegar?), or to both of them ?

2) if sensitivity results essentially from the onions, how would this apply to

the case of

irrigation with onion juice?

Is anyone still irrigating successfully with onion juice ?

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ABSTRACT

Clin Exp Allergy. 1995 Aug;25(8):698-703.Links

Comment in:

Clin Exp Allergy. 1995 Aug;25(8):680-1.

Pickled onion-induced asthma: a model of sulfite-sensitive asthma?

Gastaminza G, Quirce S, M, Tabar A, Echechipía S, Muñoz D, Fernández de

Corres L.

Servicio Alergología, Hospital Santiago Apóstol, -Gasteiz, Spain.

BACKGROUND: Asthma elicited by sulfite ingestion has been mainly described in

steroid-

dependent and in non-atopic asthmatics. We have studied a group of 18 young

extrinsic

asthmatics who presented with asthma attacks immediately after eating pickled

onions.

OBJECTIVE: The aim of this study is to ascertain if these asthma attacks are

elicited by

sulfites contained in pickled onions and the influence of the dose and pH of

onions.

METHODS: The bronchial hyperreactivity of the patients was assessed by a

methacholine

challenge test. Oral challenge tests were performed with sodium metabisulfite

(MSB)

diluted in lemon juice at pH 4.2 and at pH 3.3 (only in patients who did not

react with pH

4.2). Two types of pickled onions, Spanish and Dutch pickled onions, were used

for oral

challenge in seven of the patients. The Monier- method was used to

measure the

SO2 concentration in pickled onions.

RESULTS: The oral provocation test with MBS, pH 4.2, elicited a positive

response in six

patients (33.3%) and the test at pH 3.3 was positive in three out of 12. No

significant

difference in PD20 values was found between these groups. Three of the seven

patients

challenged with Spanish pickled onions had a positive reaction but had no

reaction with

Dutch pickled onions. The SO2 concentration in Spanish pickled onions varied

between

765 and 1182 ppm while in Dutch pickled onions were 200 ppm; this exceeded the

permitted level (100 ppm). SO2 release in Spanish pickled onion samples was

nearly 2.5

times higher when the pH of the sample decreased from 4.2 to 3.3.

CONCLUSION: High levels of SO2 in Spanish pickled onions, and their low pH (3.3)

would

be the responsible factors of the asthmatic outbreaks after ingestion of Spanish

pickled

onions by these patients.