Skin Itching (Pruritus)

Why skin itches

Itch is carried by specific nerve fibers in the skin. They are activated by histamine (in hives and bites) and by many other chemical messengers released in inflamed or damaged skin, and by substances circulating in the blood, such as bile acids in liver disease. Scratching relieves the itch briefly but damages the skin, which releases more itch chemicals: the itch-scratch cycle. Thickened, leathery skin from long-term scratching is called lichen simplex chronicus.

Itching with a rash: skin causes

Itching without a rash

If you itch but your skin looks normal apart from scratch marks, doctors consider:

Dry skin and aging

The commonest cause, especially in people over 65. Skin can look only slightly dry.

Medicines

Opioids, some blood pressure medicines (ACE inhibitors, calcium channel blockers), statins, antimalarials, hormone therapy and many others can cause itch. Itch can start weeks after a medicine begins.

Liver and bile duct disease

Bile flow problems (cholestasis) from primary biliary cholangitis, primary sclerosing cholangitis, hepatitis, gallstones or tumors cause itching that is often worst on the palms and soles and at night. Jaundice may come later. In late pregnancy, intrahepatic cholestasis of pregnancy causes intense itch and needs monitoring because of risks to the baby.

Kidney disease

Many people with advanced chronic kidney disease or on dialysis have persistent, widespread itch.

Blood and hormone disorders

• Iron deficiency, even without anemia
• Polycythemia vera: prickling itch after a warm bath or shower (aquagenic pruritus)
• Hodgkin lymphoma and other lymphomas, sometimes with night sweats, fevers and weight loss
• Overactive or underactive thyroid
• Diabetes, mainly through dry skin and infections

Nerve causes

Damaged nerves can cause localized itch without a rash: between the shoulder blades (notalgia paresthetica), on the outer arms after sun exposure (brachioradial pruritus), and after shingles.

Psychological factors

Stress and anxiety worsen most itch. In some people, itch is driven mainly by psychological factors, but this is a diagnosis made after other causes are excluded.

Itchy skin at night

Most itch feels worse at night, because skin temperature rises, there are fewer distractions, and natural anti-inflammatory hormones dip. Itch that is strikingly worse at night suggests scabies, bedbugs, eczema, or liver or kidney causes.

How doctors find the cause

A clinician will ask when the itch started, where it is, what makes it better or worse, medicines, bathing habits, contacts with itchy people, travel, pregnancy, and general symptoms like weight loss or night sweats. They examine the whole skin.

If there is no obvious skin cause, initial blood tests usually include:

• full blood count and ferritin (iron stores)
• liver function and kidney function
• thyroid function
• blood sugar
• sometimes HIV and hepatitis tests, and a chest X-ray if lymphoma is suspected

Skin scrapings can identify fungus or scabies mites, patch testing identifies contact allergies, and a skin biopsy helps with unclear rashes.

How to relieve itchy skin

Skin care

• Moisturize with a thick, fragrance-free cream or ointment at least twice a day and within 3 minutes after bathing.
• Bathe in lukewarm water for 10 minutes or less, and use a mild, soap-free cleanser.
• Pat dry, do not rub.
• Wear loose cotton clothing, and avoid wool and rough fabrics.
• Keep nails short, and try pressing, tapping or applying cold instead of scratching.
• Cool compresses or a cool room at night.
• Avoid triggers: fragranced products, harsh detergents, hot baths and alcohol.

Over-the-counter options

• Non-drowsy antihistamines such as cetirizine or loratadine work well for hives but less well for most other itch. Follow the label dose.
• Hydrocortisone 1% cream for small areas of eczema or bites, for up to 7 days unless advised otherwise. Not for the face for long periods, or for fungal rashes.
• Calamine lotion, menthol creams or pramoxine give short-term relief.
• Sedating antihistamines may help sleep but cause next-day drowsiness and are not advised for older adults.

Medical treatments

• Prescription steroid or non-steroid creams for eczema and psoriasis.
• Treatments for scabies (for everyone in the household) and fungal infections.
• Treating the underlying disease for systemic causes, including specific medicines for itch in liver and kidney disease.
• Phototherapy (UV light) for some chronic itch.
• Medicines that act on nerves for neuropathic or chronic itch.
• Biologic medicines for severe eczema and some chronic itch conditions.

Frequently asked questions

What causes itching all over the body with no rash?

The most common cause is dry skin, especially in older adults. Other causes include medicines, liver or kidney disease, thyroid disease, iron deficiency, pregnancy and, rarely, lymphoma or polycythemia vera. If itching lasts more than 2 weeks without a clear reason, see a doctor for blood tests.

Why is my skin itchier at night?

At night your skin warms up, loses more moisture and your body makes less of its natural anti-inflammatory hormones, while there are fewer distractions. Eczema, dry skin, scabies and bedbugs are classic causes of night-time itch. A cool bedroom and moisturizing before bed help.

Can stress cause itchy skin?

Yes. Stress can trigger or worsen hives, eczema and psoriasis, and it makes any itch feel more intense. Stress-related itch is real, but persistent itching should still be checked for skin and medical causes before being put down to stress.

Can itchy skin be a sign of something serious?

Usually it is not. But itching without a rash that lasts weeks, especially with jaundice, weight loss, night sweats or fatigue, can be a sign of liver disease, kidney disease or blood disorders including lymphoma. Blood tests help rule these out.

What is the best thing to stop itching?

For most itch, the best steps are frequent use of a fragrance-free moisturizer, short lukewarm showers, gentle cleansers and cool compresses. Antihistamines help hives and bites. Hydrocortisone cream helps small areas of eczema. Treating the underlying cause gives lasting relief.