Capsaicin is a substance found in hot chili peppers. When applied
to the skin over the affected area, medicines containing capsaicin may be
used as pain relievers for rheumatoid arthritis, postherpetic neuralgia, and
When applied to the skin, capsaicin affects the skin's nerve
impulses, blocking the pain without blocking other sensations. Its use should
be directed by a doctor. It may take several weeks to feel the
effects of capsaicin.
Some people can't tolerate capsaicin, which may cause burning,
stinging, or redness of the skin. Capsaicin can cause extreme pain if applied
to an open rash or if it gets in the eyes.