By Dr. Paul Ehrlich

As faithful readers of this website and our book know, changing weather brings with it allergic symptoms, most of which allergists can predict. For example, I am writing this on the day (January 2, 2013) that New York City sanitation workers start picking up Christmas trees left on the curb. Those who leave their trees up too long are inviting allergic rhinitis and asthma because the trees start to grow highly allergenic molds, although many of them attribute their symptoms to something else.
I recently had a new seasonal-allergy mystery. When the weather turned cold, a patient treated himself to a nice new down jacket from L.L. Bean, went out in the cold and soon broke out in terrible hives. Was it the feathers? “Doctor, help me!”
As I confronted this worried patient I examined the coat, and it didn’t seem likely that enough allergen could escape the “Densely woven waterproof TEK2® polyester shell” to make him sneeze, let alone provoke hives on the scale that now confronted me. Feathers are primarily an environmental allergen that can trigger sneezing and asthma, if you happen to have a parrot attached to them, or if they are lying around the house gathering dust. I did have one patient a long time ago who did react upon contact with feathers—see page 214 of our book—which constituted a major threat in her chosen profession, which involved both wearing feathers and, significantly, removing them as she worked.
With my current patient we did a skin prick test, and he showed negative to feathers. But I had another theory. I told him his jacket was safe to wear, and when he went outside he immediately started to hive up again. Just as I thought. He had a nasty condition called cold-induced urticaria, which is non-allergic. Exposure to cold air or swimming in cold water can cause mast cells to degranulate in the skin and sometimes the throat, which can be dangerous. It is best treated by avoiding direct contact with the cold and with Periactin (cyproheptadine), an otherwise seldom-used antihistamine.
When I was an allergy fellow at Walter Reed Army Medical Center (WRAMC), the service flew to Washington, D.C. a ten-year-old boy, the son of a career service man stationed in northern Michigan. This child had decided to take a swim in a small lake near his base the first week of March. He jumped in, immediately turn blue, swelled and stopped breathing. Fortunately, he was saved and made his way to WRAMC.
We took an ice cube out of the freezer and placed it on his forearm for five minutes. After removing it we all watched the area on which it was placed. Within minutes a huge hive appeared, and the diagnosis of cold-induced urticaria was made. The family was relocated to a navy base in Florida where he proceeded to swim with impunity.