What Are the Causes of Pruritus?

Pruritus, or itching, may be caused by a variety of conditions.

Pruritus means anitch.Itchingis an extremely uncomfortable skin sensation that results in the urge to scratch. Pruritus can be caused bydry skin,allergies, infections, and other systemic conditions. Depending on the cause of pruritus, the skin may appear normal, red, rough, or bumpy. Pruritus can last a long time and can be intense. Repeated scratching can cause raised, thickened areas of skin that may bleed and become infected. Treatment of pruritus depends on the cause. Home remedies, such as moisturizing, using gentle cleansers, and bathing with lukewarm water, can help.Over-the-counterand prescription creams, ointments, and oral medication can help relieve severeitch.

The following are causes of pruritus.

• Skin conditions:Xerosis(dry skin),eczema(dermatitis),fungal infections,scabies,psoriasis, parasites,burns,scars,insect bites,hives, etc.
• Underlying diseases: Pruritus might be a symptom of an underlying illness, such asanemia,diabetes,liver disease,kidney disease, thyroid problems,multiple myeloma, orlymphoma.
• Neurological disorders:Multiple sclerosis, pinched nerves, andshingles(herpes zoster)
• Psychiatric conditions:Anxiety,obsessive-compulsive disorder, tactilehallucinations, anddepression
• Irritation andallergicreactions: Irritation to things, such as wool, chemicals, soaps,cosmetics, and other substances, can irritate the skin and causerashesanditching. Often, sweat accumulates in the groin and armpits and causes itching.

Pruritus can affect certain areas of the body (such as the face,scalp, an arm or a leg, a small patch of skin) or the entire body. At times, pruritus may not cause any noticeable changes on the skin or may be associated with the following:

• Redness
• Raised skin
• Scratch marks
• 疙瘩, spots, orblisters
• Extremelydry skin
• Cracked skin
• Leathery or scaly patches

It is recommended to see a doctor in the following cases:

• Pruritus interferes with your daily routine or affectssleep
• Pruritus lasts longer than 2 weeks and does not improve with home remedies or over-the-counter medication
• Pruritus begins suddenly and can't be easily explained
• Affects the entire body
• Pruritus in the genital area, especially if it is associated with discharge
• Pruritus associated with systemic signs and symptoms, such asweight loss,fever,night sweats, yellow discoloration of the eyes and skin, or dark-colored urine

The doctor would perform a complete physical exam and may suggest the following:

• Blood tests, such as acomplete blood count
• Tests for thyroid,liver, and kidney function
• Chest X-ray

Treatment options for pruritus include the following:

• Corticosteroidcreams and ointments: These can reduce inflammation, itching, and redness. The ointments may contain 0.025%-0.1% corticosteroid. It is advised not to use steroid creams for more than 7 days because steroids can cause the skin to thin out. They can also increase the chances of fungal infection in the irritated area.
• Other creams and ointments: Other topical treatments include calcineurin inhibitors that provide relief.
• 口服药物: Medications would include anti-itching medications, antibiotics, orantidepressantsdepending on the cause.
• Light therapy (phototherapy): Phototherapy uses a specific type of light to control the sensation of itching.

These measures can temporarily help relieve itching:

• Avoid irritants.
• Moisturize the skin every day using hypoallergenic and fragrance-free moisturizers.
• Treat dry,itchy scalpwith over-the-counter medicated shampoos containing zinc pyrithione,ketoconazole, and selenium sulfide. Serums that maintain the pH and retain the inherent natural barrier of the scalp are available in the market. These contain urea and lactate compounds that help lock in the moisture in the scalp.
• Managestress.
• Use over-the-counter oralallergymedicine, such asdiphenhydramine,cetirizine, andfexofenadine.
• Use a humidifier to relieve dry skin. These may contain urea,glycerin, and other natural ingredients.
• Use creams, lotions, or gels that soothe and cool the skin. For example,calamine lotionor creams with menthol, camphor, capsaicin, or a topical anesthetic, such aspramoxine(for adults only).
• Avoid scratching by covering theitchyareas.
• Take a bath with lukewarm water and about half a cup (100 grams) of Epsom salts, baking soda, or oatmeal-based bath products.
• Get adequate rest, hydration, and a healthydiet.