Potential pruritus treatments are as varied as its causes

November 1, 2011

In the elderly population, the sources of itching are the same as those affecting anyone else, but the causes of their discomfort are usually exacerbated by age, according to Jeffrey Bernhard, M.D., a dermatologist who practices in Worcester, Mass.

Key Points

Worcester, Mass. - In the elderly population, the sources of itching are the same as those affecting anyone else, but the causes of their discomfort are usually exacerbated by age, according to Jeffrey Bernhard, M.D., a dermatologist who practices in Worcester, Mass.

The good news, Dr. Bernhard says, is that at the Sixth World Congress on Itch held recently in Brest, France, the causes and potential treatments for itch created much excitement among attendees.

"Almost 200 people attended the meeting, interested in everything about itching - from basic research and clinical science to advanced diagnosis and treatment," says Dr. Bernhard, who co-authored the medical textbook Itch in 1994.

Dr. Bernhard says there are several causes of itching that occur more commonly in seniors, including winter itch, which is typically caused by dry air, common in the winter months.

"Ironically, 'winter itch' can even occur in summer, particularly in elderly people exposed to a completely air-conditioned environment," he says. "In either case, skin dryness and itch are aggravated by harsh soaps and prolonged showers or baths."

Taking baths less frequently and for shorter durations, using milder soap and moisturizing immediately after bathing can help to alleviate this condition.

A number of medications can exacerbate or stimulate itch, particularly pain relievers.

"It's intriguing that drugs that relieve pain can cause itch," Dr. Bernhard says. "It has to do with opioid receptors. But pain relievers are not the only drugs that can cause itching. In any case of otherwise unexplained itching, the drug history should be carefully explored."

Willan's itch, previously known as senile pruritus, may have a number of causes and still is not well understood, according to Dr. Bernhard.

"One possibility is that some neurons in the skin - suppressor or inhibitory neurons - which previously acted to block itching from occurring, become less active with age," he says.

Nerve damage

Dr. Bernhard says he believes one of several potential causes for itching in the elderly for which there is no other explanation may be a peripheral neuropathy.

"Based on that possibility, treatment with gabapentin can be helpful because it is useful in treating neuropathies, although its use in treating itch is not FDA (Food and Drug Administration) approved," he says.

Other itchy conditions, Dr. Bernhard says, can occur as a consequence of peripheral sensory neuropathies, including notalgia paresthetica (NP), which occurs on the back, and Brachioradial pruritus (BRP) on the arms.

NP and BRP are thought to be isolated peripheral sensory neuropathies, perhaps caused by nerves being "pinched" somewhere between where they leave the spinal cord and where they enter the skin. Understanding that they're related to the nervous system, and are not skin diseases per se, led to the realization that drugs affecting the nervous system, such as gabapentin or pregabalin, might be used, off-label, to treat them.

Dr. Bernhard says other important causes of itching in the elderly are the same as those found in other age groups, including eczema, psoriasis, allergic and irritant contact dermatitis, and so forth.

Scabies occurs in the elderly and can be very difficult to diagnose, especially if there is not a high index of suspicion.