•Itches resulting from histamine reactions may be triggered by allergic contact dermatitis. Antihistamines and cortisone creams often are effective. But most chronic itching isn't caused by a histamine reaction: It could be an overactive thyroid, eczema, psoriasis, dry skin, kidney or liver failure, certain cancers or a pinched or damaged nerve.
•Itch messages go from skin cells to your brain. They can come in contact with pain pathways. If itching goes on long enough, it can take over neurons that transmit pain.
•Each type of itch calls for its own remedy. Are you anemic? Do you have undiagnosed or uncontrolled diabetes or thyroid disease? How's the health of your liver and kidneys? Get a thorough workup.
We also know that certain medications used for other conditions may help. For example, some folks get relief from SSRIs, used to treat depression; gabapentin used to treat restless leg syndrome, seizures and nerve pain; pregabalin used to treat fibromyalgia and nerve pain; paroxetine used to treat obsessive compulsive disorder; and opioid antagonists used to counter opiate overdoses.
Q: My husband, 70, broke his ankle two years ago, and he still limps around in pain that keeps him awake at night. He's always under a lot of stress, so I was wondering, could stress be why he isn't healing properly? — Susan D., Freeport, N.Y.
• Many factors, such as weight, poor nutrition, lack of exercise or physical therapy, and especially chronic stress, can contribute to a slow-healing ankle. Studies on skin repair following surgery show that stress slows down wound healing by as much as 40 percent. We also know that stress can worsen asthma, cardiovascular and heart disease, obesity, diabetes, headaches, depression and gut problems, and it can accelerate aging. So it seems very likely that stress is playing a part in your husband's slow ankle recovery.
Fortunately, the damage from chronic stress can be controlled. Suggest he try meditation, deep breathing exercises, Hatha yoga (there is no wrong position, just do what you can), biofeedback, restful music or spending time with a pet.