Gluten is difficult to seek out; it may lurk where you least expect it, particularly at restaurants as a visitor to an Indian restaurant found to their dismay.
Least expecting gluten (which is usually found in wheat flour or all purpose flour), it was a shock to find that the fried onions used in the restaurant used wheat flour.
The restaurant owner assured that the wheat flour content was very little, but it was enough to set off a debilitating allergic reaction.
What allergy sufferers would do well to learn from this story is not to shy away from asking pertinent questions at restaurants. As for a gluten allergy, the rule to follow may be: the less you eat out the better!