Chronic pruritus is defined as itching that lasts for 6 weeks or longer.
Chronic pruritus accounts for about 7 million physician visits annually in the US and affects approximately 22% of people during their lifetime. Chronic pruritus is associated with impaired sleep and reduced quality of life.1
What Are the Symptoms and Signs of Chronic Pruritus?
Some people with chronic pruritus have a “pure” itch—an uncomfortable sensation that results in an urge to scratch the skin. Others have pain or a burning, prickling, stinging, or crawling sensation on their skin. Symptoms may be mild, moderate, or severe and can occur at different times of the day, in different seasons, or in response to various exposures such as water, sunlight, or pressure on the skin. Patients with chronic pruritus may have normal-appearing or inflamed skin.
What Are the Different Types of Chronic Pruritus?
-
Inflammatory pruritus accounts for approximately 60% of cases of chronic pruritus and results from an immune system reaction due to conditions such as eczema, psoriasis, seborrheic dermatitis, and hives.
-
Neuropathic pruritus is itching that results from nerve damage, such as a pinched nerve in the neck that causes itching across the middle of the back and the sides and backs of the arms, or nerve damage from shingles that causes itching in affected skin areas. Although most neuropathic pruritus is localized to specific areas of the body, diabetes can cause nerve damage that contributes to itching across the body.
-
Inflammatory and neuropathic pruritus causes chronic pruritus in many people, including patients with HIV-associated pruritus. Intensely scratching an area of skin affected by nerve damage also can trigger an inflammatory immune system response.
-
Other causes account for about 15% of chronic pruritus and include kidney and liver disease; medications such as opioids, amphetamine/dextroamphetamine, and immunotherapy drugs; parasitic infestation such as scabies; or skin infection such as ringworm.
People with chronic pruritus symptoms lasting less than 1 year and without skin rash are more likely to have an underlying disease causing pruritus. They may undergo blood testing to assess kidney, liver, and thyroid function.
How Is Chronic Pruritus Treated?
Approximately 90% of patients with chronic pruritus improve with therapies applied directly to the skin (topical therapies). First-line treatment for inflammatory chronic pruritus includes topical anti-inflammatory medications such as hydrocortisone, triamcinolone, and tacrolimus ointment. Neuropathic itch can be effectively treated with topical analgesics such as menthol, pramoxine, and lidocaine. Patients with inflammatory and neuropathic pruritus can receive treatment with combinations of these topical therapies.
Patients who do not improve with topical therapies should be referred to a dermatologist for further evaluation and treatment. Phototherapy, which involves exposure to UV light, may relieve inflammatory itch. Oral or injectable treatments such as methotrexate or dupilumab can help reduce inflammatory pruritus. Advanced treatments for neuropathic pruritus may include gabapentin, antidepressants such as sertraline or doxepin, or opioid receptor agonists/antagonists such as naltrexone or butorphanol.
Reducing stress or anxiety can also help relieve chronic pruritus. Cognitive behavior therapy, progressive muscle relaxation, transcutaneous electrical neurostimulation, acupuncture, and patient education can be effective additions to medications.
Source-AMA 12/3/2024