Itch & Neuropathic
Chronic Pruritus of Unknown Origin
CPUO; chronic itch, cause unclear
Common, especially in older adults
No — you cannot catch it or spread it
Manageable; often improves with treatment
What Is It?
Chronic pruritus of unknown origin is ongoing itch lasting more than six weeks without a clear rash or identified cause after initial evaluation. The skin may look normal or show only scratch marks. It's more common with age and can significantly affect sleep and quality of life, but it can usually be improved with a stepwise approach.
Signs & Symptoms
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Persistent itch lasting more than six weeks
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Skin that looks normal or shows only scratch marks
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Itch that may be widespread or move around
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Often worse at night or with heat and dryness
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No clear primary rash to explain it
Why Does It Happen?
Itch has many possible drivers — dry skin, nerve changes, immune signals, and sometimes internal conditions (thyroid, kidney, liver, blood, or nerve issues) or medications. In CPUO, no single cause is found at first, and age-related dry skin and nerve changes often contribute. A focused workup helps rule out treatable internal causes. It is NOT contagious.
Treatment Options
Care combines a workup for hidden causes with treatments that calm the itch. A layered approach — skin care plus itch-targeted medicines — usually brings relief.
SKIN CARE
Frequent moisturizing and gentle, fragrance-free products.
WORKUP
Bloodwork and review of medications to find treatable causes.
ITCH-TARGETED MEDICINES
Nerve-calming agents, topical options, or newer therapies.
PHOTOTHERAPY
UV light therapy helps some people with widespread itch.
Tips for Managing It at Home
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Moisturize often; use lukewarm water and gentle cleansers
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Keep cool and wear soft, breathable clothing
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Keep nails short; use cool compresses instead of scratching
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Complete recommended bloodwork to check for hidden causes
When to Call Your Provider
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Itch with weight loss, night sweats, or feeling unwell
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Yellowing of skin/eyes, or very dark urine
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Severe itch disrupting sleep or daily life
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No improvement with initial measures
Sources & further reading
The information in this handout is based on general dermatology guidance from the reputable organizations below. These links are provided for patients who wish to read more from trusted sources.
American Academy of Dermatology (AAD). Itchy Skin: Causes. https://www.aad.org/public/everyday-care/itchy-skin/itch-relief/relieve-uncontrollably-itchy-skin
Canadian Dermatology Association (CDA). Dry Skin. https://dermatology.ca/public-patients/diseases-conditions/skin-conditions/dry-skin/
DermNet. Pruritus (Itch). https://dermnetnz.org/topics/itch
MSD/Merck Manual. Pruritus. https://www.msdmanuals.com/professional/dermatologic-disorders/approach-to-the-dermatologic-patient/pruritus
This handout is for general education and does not replace advice from your own provider. Always follow your provider’s specific instructions.
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