Pruritus

Pruritus is the medical term for itching—an uncomfortable sensation that makes you want to scratch your skin. While everyone experiences itching at some point, chronic pruritus can be more than just a nuisance. It can disrupt sleep, affect mental health, and significantly impact quality of life, sometimes as much as chronic pain does.

Table of contents

• What is pruritus?
• Types of pruritus
• Who is affected by pruritus?
• Symptoms of pruritus
• What causes pruritus?
• How is pruritus diagnosed?
• Treatment options
• Prevention and self-care

What is pruritus?

Itch, Itchy skin
L29

Pruritus is the medical term for itching. It refers to an irritating sensation on your skin that creates the urge to scratch^[1]. The term “itch” is commonly used in everyday language, but in medical settings, healthcare professionals often refer to this condition as pruritus^[3].

The sensation of itching is different from other skin sensations like pain, touch, or temperature. What makes itching unique is its aggravating nature that specifically triggers the desire to scratch^[3]. Pruritus can affect a small area, such as the scalp, an arm, or a leg, or it can cover your entire body^[2].

When itching persists for six weeks or more, it is considered chronic pruritus^[1]. Chronic itching can be just as debilitating as chronic pain, significantly affecting a person’s quality of life^[3][12].

Types of pruritus

Pruritus can be classified in several ways. Based on how the itch develops, there are four main categories^[3]:

• Cutaneous (pruritoceptive) itch: Caused by inflammation of the skin
• Neuropathic itch: Results from damage anywhere along the nerve pathway
• Neurogenic itch: Originates in the central nervous system without evidence of nerve damage
• Psychogenic itch: Associated with psychological conditions

Pruritus can also be categorized by location or cause. Some common specific types include^[1]:

• Brachioradial pruritus: Itching of the upper arm caused by nerve damage
• Nocturnal pruritus: Itching that occurs at night, which may be caused by natural body functions, medications, or skin irritants
• Pruritus ani: Itching around the anus, often caused by hemorrhoids, infection, or irritants
• Senile pruritus: Itching caused by age-related skin changes affecting people over 65
• Uremic pruritus: Itching that occurs in people with kidney disease who receive dialysis

Who is affected by pruritus?

Pruritus is very common and will affect everyone during their lifetime^[1]. The severity and how often it occurs varies from person to person. While large-scale studies on its prevalence are limited, pruritus is a common symptom encountered in primary care^[9]. One population-based study in France estimated that about 12.4% of people experienced pruritus during a two-year period^[5].

In general, the occurrence of chronic pruritus increases with age, is more common in women, and in people of Asian background^[5]. You may be at higher risk of experiencing pruritus if you^[1]:

• Are 65 years or older
• Have allergies
• Have an underlying condition like eczema, psoriasis, or diabetes
• Are pregnant
• Are on dialysis

Symptoms of pruritus

The main symptom of pruritus is the sensation of itching—an uncomfortable feeling that makes you want to scratch your skin to get relief^[1]. However, scratching doesn’t always provide relief.

Pruritus can feel different for different people. Sometimes it can be painful, while other times it might feel like something is tickling your skin^[1]. The itching can be localized to one spot or spread across several areas of your body.

If you scratch your itchy skin, you may develop additional symptoms^[1]:

• Dry or cracked skin
• Scratch marks (also called excoriations)
• Thick, leathery patches of skin (called lichenification)
• Pain at the site of scratching
• Skin that breaks open and bleeds
• Signs of infection—broken skin that leaks yellow or white fluid, doesn’t heal, or develops a scaly or crusty texture

Additional symptoms may accompany itchy skin^[1][2]:

• Skin discoloration—lighter or darker than surrounding skin
• A rash that is raised or swollen (inflammation)
• Small pimple-like bumps (called papules)
• Large bumps
• Blisters or fluid-filled bumps

Sometimes you may experience itchy skin without any visible changes, while other times itching comes along with a rash or other skin changes^[1].

The itch-scratch cycle

Eczema and other skin conditions are frequently made worse by what’s known as the “itch-scratch cycle”^[17]. This happens when itching leads to scratching, which causes the release of inflammatory substances in the skin, which then causes more dryness and more itching^[17].

While scratching may temporarily relieve the itch by causing mild pain, this relief is short-lived^[17]. Too much scratching can lead to more eczema, thickened skin, scarring, and infections if the skin surface is broken^[1][5].

What causes pruritus?

Pruritus has many possible causes. The most common include contacting an allergen, dry skin, pregnancy, and reactions to medications^[1]. Itchy skin is often caused by dry skin and is particularly common in older adults, as skin tends to become drier with age^[2].

How itching works in the body

The sensation of itching is transmitted through special nerve fibers in the skin. These are slow-conducting nerve fibers with endings located near the surface of the skin^[3][7]. Various substances can activate these nerves, including^[7]:

• Histamine
• Neuropeptide substance P
• Serotonin
• Bradykinin
• Proteases (such as mast cell tryptase)
• Endothelin

Signals from these nerve endings travel from the skin to the spinal cord and eventually to the brain, where they are interpreted as the sensation of itching^[7].

Skin-related causes

Pruritus is most commonly associated with skin conditions^[7]. Common skin-related causes include^[9]:

• Dry skin (xerosis)
• Eczema and atopic dermatitis
• Contact dermatitis (allergic or irritant)
• Psoriasis
• Urticaria (hives)
• Drug reactions
• Insect bites
• Scabies

Systemic causes

When a primary skin condition cannot be identified, pruritus may be a sign of a systemic disease^[7]. Systemic diseases that can cause generalized pruritus include^[7][9]:

• Chronic kidney disease and kidney failure
• Liver disease and cholestasis (blocked bile flow)
• Diabetes
• Thyroid disorders (such as hyperthyroidism)
• Anemia and iron deficiency
• Blood disorders
• Certain cancers
• HIV/AIDS

Other causes

Additional causes of pruritus include^[6]:

• Allergic reactions to food, pollen, or medicines
• Parasites such as pinworms or lice
• Pregnancy
• Nerve-related conditions
• Psychological conditions

Medications can also cause itching^[18]. If pruritus starts after beginning a new medication, it’s important to discuss this with your healthcare provider.

How is pruritus diagnosed?

Diagnosing the cause of itchy skin begins with a physical examination and questions about your medical history^[10]. Your healthcare provider will want to know details about when the itching started, where it occurs, what makes it better or worse, and what other symptoms you have^[9].

Physical examination

A thorough skin examination is essential^[9]. Your healthcare provider will look at your entire body, including areas that may be difficult to see yourself, such as the finger webs, genital area, nails, and scalp^[9].

The examination focuses on distinguishing between primary and secondary skin changes. Primary lesions are signs of diseased skin and indicate a skin condition is causing the itch. Secondary lesions are reactive changes that result from scratching, such as scratch marks, thickened skin, or scars^[9].

Laboratory tests

If your healthcare provider suspects an underlying medical condition, you may need blood tests or other investigations^[10]. Initial testing for systemic causes may include^[9][13]:

• Complete blood count with differential
• Kidney function tests (creatinine and blood urea nitrogen)
• Liver function tests
• Iron studies
• Fasting glucose or A1C level (for diabetes)
• Thyroid-stimulating hormone test

Additional testing may be appropriate based on your history and examination, such as^[9]:

• HIV screening
• Hepatitis tests
• Chest X-ray

In older patients with chronic generalized pruritus without obvious skin disease, healthcare providers may consider evaluation for cancer^[9].

Additional skin tests

For persistent, unexplained pruritus, your healthcare provider may recommend additional skin testing such as^[9]:

• Skin biopsy
• Skin scrapings
• Cultures

Treatment options

Treatment for pruritus focuses on removing or addressing the cause of the itch^[10]. Without treating the underlying condition, management is often aimed at providing relief from symptoms^[7]. Controlling itchy skin symptoms can be challenging and may require long-term treatment^[10].

General management approaches

Initial management of pruritus includes^[9][12]:

• Avoiding triggers (such as rough textiles, detergents, perfumes, or chemicals)
• Using moisturizers liberally and regularly
• Limiting water exposure
• Taking lukewarm (not hot) baths
• Using gentle, fragrance-free cleansers

Topical treatments

Corticosteroid creams and ointments are commonly used when skin is itchy and inflamed^[10]. Your healthcare provider may suggest applying medicated cream to affected areas and then covering the treated skin with damp cotton material to help the skin absorb the medication and provide a cooling effect^[10].

Other topical treatments may include^[10]:

• Calcineurin inhibitors such as tacrolimus or pimecrolimus
• Cooling gels containing menthol
• Regular moisturizers (emollients)

For some types of localized pruritus, capsaicin cream may be effective^[16].

Oral medications

Antihistamines are often used for initial treatment, although they work better for some causes of itching than others^[9][16]. Sedating antihistamines may be particularly helpful for nighttime itching that interferes with sleep^[16].

Other systemic medications that may be used include^[12][16]:

• Gabapentin (particularly for nerve-related itching)
• Antidepressants (such as doxepin or mirtazapine)
• Specific medications for kidney-related or liver-related itching

Other treatment options

For certain types of pruritus, additional treatments may be recommended^[16]:

• Phototherapy (ultraviolet light therapy), particularly for kidney-related pruritus
• Cognitive behavioral therapy and lifestyle modifications for resistant symptoms^[9]
• Treatment of the underlying condition (such as managing diabetes, treating kidney disease, or addressing liver problems)

Prevention and self-care

There are many steps you can take at home to prevent itching or reduce its severity^[8][21][22]:

Washing and bathing

• Limit the number of baths or showers you take
• Use lukewarm water instead of hot water
• Avoid soaking in the bath for long periods, as this can remove the skin’s natural oils
• Use gentle, fragrance-free cleansers instead of regular soap
• Pat your skin dry with a towel rather than rubbing
• Apply moisturizer immediately after bathing while skin is still slightly damp

Moisturizing

• Use odorless and colorless moisturizers regularly
• Avoid perfumed, scented, and lanolin-based products, as these can cause allergic reactions
• Apply moisturizer in the same direction as hair growth; don’t rub vigorously
• Try refrigerated moisturizer for additional soothing effect

What to wear

• Choose cotton and linen fabrics rather than wool or synthetic materials
• Keep bedclothes light
• Wear cotton gloves at night to avoid scratching in your sleep

Other helpful tips

• Keep your nails short to reduce damage from scratching
• Keep room temperature cool and even, as getting hot can make itching worse
• Use a fan to cool down if you feel hot and itchy
• Drink plenty of water (2 to 3 liters a day)
• Avoid highly perfumed washing products
• Try to distract yourself with activities like watching a film or reading
• Practice mindfulness, which can help break the itch-scratch cycle

What to do instead of scratching

When you feel the urge to scratch, try these alternatives^[22]:

• Gently pinch an area of skin close to the itch
• Rub, tap, or press the area gently
• Apply a cool pack to the skin
• Apply more moisturizer gently

When to contact your healthcare provider

You should see a healthcare provider if your itching^[2][22]:

• Lasts more than two weeks and doesn’t improve with self-care
• Is severe and interferes with daily activities or sleep
• Comes on suddenly and can’t be easily explained
• Affects your whole body
• Comes with other symptoms such as weight loss or fever
• Gets worse despite treatment
• Shows signs of infection (increased redness, warmth, swelling, pus, or odor)