Many people have wool sensitivities or wool allergies that keep them from knitting with wool yarn or force them to use blends that don't include a lot of wool. But what is a wool allergy and how does it differ from a sensitivity? How common are these problems?
What We Know About Wool Allergies
Most medical experts, while not discounting the discomfort caused by wool sensitivity, say that true wool allergies are rare.
A person with wool allergies has an allergic response, just like a person with an allergy to cats or pollen would have when they come into contact with those allergens.
Forty to 50 million people, or about 20 percent of the population of the United States, have some kind of allergies. It's not known exactly how many people are allergic to wool.
The most common side effect of a wool allergy is a rash on the face, arms, and hands. This rash may occur immediately after contact with the wool or it may take a couple of days for the rash to appear.
It is thought that most wool allergies are actually a reaction to wool alcohols, which are the main ingredients in lanolin. If you have a reaction to lotions, creams, and makeup that contain lanolin, you'll also have a problem with raw wool.
To determine if you have a true wool allergy, a patch test can be conducted using wool alcohols. If you are found to be allergic to wool, you will have to find a different fiber to knit with.
What Is Wool Sensitivity?
Far more common than a wool allergy, many people with sensitive skin feel uncomfortable wearing wool. Their skin is often irritated as well, but they do not have a true allergic reaction.
Many people who think they are allergic to wool have sensitive skin that would be irritated by any kind of coarse fiber.
Others, who might have a runny nose when they wear a wool sweater, might actually be reacting to dust mites or other allergens that are caught in the weave of the wool rather than having a problem with the wool itself.
One study showed that people wearing wool sweaters were exposed to 10 times more cat dander than people wearing no shirts were exposed to in homes with cats. That makes it especially important to keep your wool away from your kitties if you're knitting for someone who is allergic to cats.
Those who are sensitive to wool should also avoid wool since there is no reason to unnecessarily irritate your body. If you don't know whether a person you are knitting for is sensitive to wool, it's best to avoid knitting with wool so that your gift will be enjoyed.
The Prickle Factor of Wool
One survey by the International Wool Secretariat found that 30 percent of Americans said they were allergic to wool, but it's actually the itchy skin reaction they were labeling as an allergy.
Scientists who study such things have found that if more than 5 percent of the fiber in a garment has a diameter of more than 30 microns or an average diameter of more than 22 microns, people will complain that the fiber is itchy.
This is why some people who claim a wool allergy may be able to happily wear other animal fibers like alpaca and cashmere, which tend to be finer than wool. Wool from the fine wool breeds, such as cormo, merino, and Targhee can have fine enough fibers that they won't upset those sensitive to coarser wool.
Some people who are sensitive to wool can successfully knit with or wear wool blends. Since each person's sensitivity is different, you might try experimenting with different wool blends, some containing more wool and some with less, to determine what your body can tolerate.
While knitting, your skin will have less contact with the wool than when wearing a knitted garment. Also, since the skin on our hands tends to be less sensitive than other parts of the body, it's a good idea to test your reaction.