Ask The Doctors: March 2018
Q: I see a lot of creams and gels for pain relief in the drug store. Can these help my arthritis?
A: Topical pain relievers can be one part of a multipronged approach to treating osteoarthritis. Some are available without a prescription. They may provide temporarily relief, especially if pain is not too severe.
Topical creams, gels, ointments and patches are generally more effective for joints nearer the skin (hands, knees, elbows) than for deeper joints (hips). Three types of topicals can be bought without a prescription.
Capsaicin is the substance in hot peppers that makes them spicy. When applied to the skin in a cream (Capzasin®, Zostrix®), it causes a slight burning sensation. (Don't get it in your eyes.) It blocks the release of a chemical messenger (substance P) that transmits pain sensations to the brain. It may take a week or two of use to feel any pain-relieving effects. The American College of Rheumatology recommends topical capsaicin for hand osteoarthritis.
Salicylates (Aspercreme®, Bengay®, Flexall®, Salonpas®) contain the same active ingredient as aspirin. They have a mild anti-inflammatory effect.
Counterirritants (Biofreeze®, Icy Hot®) create a temporary heating or cooling sensation, which may interfere with transmission of pain signals. They contain ingredients such as menthol, eucalyptus and camphor.
If none of these help, talk to your doctor about a prescription topical drug, such as the nonsteroidal anti-inflammatory drug (NSAID) diclofenac (Voltaren Gel®, Pennsaid®). By delivering the drug through the skin, there may be fewer gastrointestinal and other side effects. Compounding pharmacies can also mix combinations of medications that may help.
Q: What is cartilage and why does it deteriorate?
A: We talk a lot about cartilage in Arthritis Advisor because it is a key player in osteoarthritis. Cartilage is a tough, yet flexible, substance that covers the ends of bones everywhere there is a joint in your body. There are different types of cartilage. The most plentiful one is articular cartilage, found in the most mobile joints (hips, knees, shoulders, elbows, wrists, hands, ankles and toes). Articular cartilage is smooth and shiny and composed of about 75 percent water. It compresses under pressure and then resumes its original thickness when the force is released. It provides a smooth surface for movement, preventing bone from rubbing against bone, which would cause friction. It also acts as a shock absorber. The thickness varies, depending on the joint. Some of the thickest cartilage in the body is in the knee joint.
Cartilage is a great protector, but it’s also susceptible to deterioration. An injury can cause damage to cartilage, or it can wear down over time. Cartilage contains no blood vessels, so once damage is done it does not heal well. Unlike other tissues in the body, cartilage does not regenerate. As we age we are more likely to develop osteoarthritis, in which cartilage breaks down. This leads to bones changing shape, deterioration of tendons and ligaments, and painful inflammation.
The mechanisms for cartilage deterioration are not entirely known, but it is being studied in an effort to find ways to prevent or reverse its effects. Three groups of researchers looking at ways to rebuild cartilage presented their findings at the American College of Rheumatology Annual Meeting (November 2017). These studies are in the early stages, but the work is promising.