Cayenne, the dried fruit of a type of pepper plant, was well known by the ancient Maya, who used it to season food, and as a medicine to treat mouth sores and inflamed gum tissue. It was brought to Europe after Christopher Columbus' voyages, and is now grown world wide. The principle active component is known as capsicum.
Capsicum is an anti-inflammatory, when used topically, and has benefit when rubbed on painful, swollen arthritic joints. Taken internally, it can reduce discomfort from the common cold, provide a mild stimulant, and can lower cholesterol blood levels. It is also an antioxidant, and contains carotenoids, Vitamin C and E. It has been recently studied for use in treatment of cluster headaches.
In a word: DON"T!! The oil containing capsicum does not wash off easily, and if you must fool with this little firecracker of a plant, use rubber gloves, and don't even THINK about touching your eyes! It is much easier, and just as effective, to let modern technology do the job for you. Buy the capsules, and take 1 to 3 a day. The very effective cream used for arthritis is usually available by prescription.
As above; also use caution if you have gastrointestinal problems, although believe it or not, red peppers are not as irritating to stomach lining as black pepper. Do not apply capsicum cream to broken skin.
Be sure of the identity of the plant before you use it. If a preparation makes you sick or gives you a rash, don't use it, and throw it away! If your condition does not improve, see your doctor. Be sure to let your physician know EVERYTHING that you are taking!