There wouldn't necessarily need to be another allergy, since people can 
have an allergic reaction to heat or cold itself.

http://en.wikipedia.org/wiki/Cholinergic_urticaria
http://en.wikipedia.org/wiki/Cold_urticaria

Margaret Wills, IBCLC Maryland


Date:    Fri, 9 Sep 2011 16:26:25 -0500
From:    Lisa Wilkins<[log in to unmask]>
Subject: Re: Maternal Hives

I have a mom who gets hives if she's in a cold room or outdoors when it's
below 70 degrees. She's found that taking 5mg OTC claritin daily will
prevent the hives nearly all of the time. She's now beginning to explore if
she has some underlying food allergies/intolerances that are stressing her
immune system to have this unusual reaction.

Lisa Wilkins

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