Causes and Treatments for Itchy Skin (Pruritus)

There are many different causes of itchy skin (also called pruritus). Causes of itchy skin can be dermatological, nerve-related, environmental, or associated with psychiatric conditions or other underlying conditions.

This article discusses what can cause itchy skin, how it's diagnosed, and treatment options to provide relief.

Common Causes of Itchy Skin

Many things can cause itchy skin, ranging from skin conditions like eczema or psoriasis to allergic reactions, underlying health conditions, and nutrient deficiencies. In some cases, the itching from these conditions will not have a tell-tale rash.

Allergies

One of the symptoms of an allergic reaction can be itchy skin. After exposure to an allergen, the body generates a robust inflammatory reaction leading to an itchy rash within one to two days. 

This reaction can be caused by:

• Poison ivy
• Poison oak
• Nail polish 
• Fragrances
• Nickel, which is found in products like cell phones, jewelry, eyeglass frames, zippers, and belt buckles
• Thimerosal, a preservative found in some topical antibiotics
  

Anaphylaxis—a severe allergic reaction that can progress into a life-threatening condition—often has symptoms involving the skin, including itching, redness, swelling, and hives.

Skin Disorders

Itchy skin is a symptom of several skin disorders, including:

• Atopic dermatitis
• Eczema
• Psoriasis
• Seborrheic dermatitis
• Skin Cancer
• Impetigo (a bacterial infection of the skin)

Reactions to Irritants

Referred to as irritant contact dermatitis, this condition doesn’t involve an allergic reaction by the immune system. Instead, it happens when skin cells are damaged by exposure to irritating substances. Substances that can cause a skin reaction include:

• Solvents (chemicals used to dissolve or dilute other substances or materials)
• Detergents
• Soaps
• Bleach
• Makeup
• Hair dye
• Excessive hand washing with hot water and soap
• Wearing scratchy wool clothing

Underlying Conditions

Itchy skin can be a symptom of several underlying health conditions, such as:

• A blood disease, such as Hodgkin’s lymphoma or cutaneous T-cell lymphoma
• Diabetes
• Kidney disease
• Liver disease
• Viral infections, such as mononucleosis, shingles or chickenpox
• HIV
• Hyperthyroidism (overactive thyroid gland)
• Stroke
• Multiple sclerosis
• Folliculitis
• Hand-foot-and-mouth disease
• Urticaria (hives)
• Pregnancy
• Cholestasis (the reduction or stoppage of bile flow in the liver)
  

Psychological Disorders

Itching can be a significant symptom of several psychiatric conditions, including depression, anxiety, obsessive-compulsive disorders, psychoses, and substance use. What causes itching associated with these conditions is not known.

Parasites

Parasites are organisms that live on or in a host organism and get their food from that organism. Parasites that cause itching in people include:

• Pinworms: this infection is caused by a small, thin, white roundworm called Enterobius vermicularis. Female pinworms leave the intestine through the anus and deposit their eggs on the surrounding skin, which causes itching around the anus.
• Scabies: the mites burrow into the upper layer of the skin where they live and lays their eggs. The most common symptoms of scabies are intense itching and a pimple-like skin rash.
• Head lice: these parasites live on the scalp and feed on blood. An itchy scalp is the most common symptom of head lice.
• Body lice: these parasitic insects live on clothing and bedding and move to the skin to feed on blood. Intense itching and rash caused by an allergic reaction to the louse bites are common symptoms of body lice infestation.

Fungal Infections

Ringworm is a skin infection caused by a fungus, not a worm. The name probably comes from the characteristics of the rash: a ring-shaped pattern and a raised, scaly border that snakes its way around the edge like a worm.

Ringworm can appear just about anywhere on the body and is characterized by intense itching.

Bug Bites

We're all familiar with the itching associated with mosquito bites, but other bugs that can also cause itching include bedbugs, fleas, spiders, sandflies, and chiggers.

Reaction to Medication

Itching can be a side effect of taking certain medications, such as aspirin, prescription-strength pain relievers like opioids, and some blood-pressure drugs. Itch can also be a side effect of some cancer treatments.

Age

As we age, our skin changes. By age 65, skin is thinner and has less moisture, leading to very dry skin that can be intensely itchy.

Nutrition Deficiencies

Studies have linked low levels of some vitamins—such as vitamins D and B12—with itchy skin. Iron deficiency has also been associated with itchy skin.

In addition, vitamin D deficiency has been associated with worse symptoms in skin conditions such as atopic dermatitis and chronic urticaria and improved symptoms when treatment includes vitamin D supplementation.

If you are experiencing chronically itchy skin, getting your vitamin levels tested in your blood may be helpful. Your healthcare provider will be able to work with you to determine whether or not a vitamin deficiency is the source of your itch and how best to treat it. Don't start any vitamin supplements without speaking to your provider first

Nerve Disorders

When a nerve isn’t working properly, it can cause itchy skin. If there’s damage along a nerve due to disease or injury, you can also develop itchy skin. This itch tends to occur in one place on your body and you don’t see a rash.

Demyelination is a type of nerve damage in which the immune system destroys the fatty covering around nerve fibers, called myelin sheath. Demyelination leads to many symptoms including sensory issues such as skin tingling, stinging, itching, or prickling sensations.

Neuropathic itch is a chronic itch under the skin that you can't scratch to relieve because it is caused by nerve damage or dysfunction rather than external stimuli like irritants or allergens.

What's Happening Inside Your Body

Itching occurs when nerve fibers in the skin send a message to the brain.

It may be caused by a local reaction to a substance or a systemic disease that triggers widespread (generalized) itchiness. In some cases, the cause may be psychological or even unknown (idiopathic).

Itching may be worse at night because of our body's sleep-wake cycle (also known as our circadian rhythm). As part of that cycle, our bodies undergo nighttime changes—such as hormone fluctuations, shifts in body temperature, and loss of skin moisture—that can make itching worse.

Regardless of the cause, with itchiness comes a desire to scratch which often makes an itch worse (and leads to more scratching). This is called the itch-scratch cycle and is an important consideration in treating pruritis.

Diagnosing Itchy Skin

Treatment for itchy skin starts by identifying the underlying cause, whether a skin condition, an allergic reaction, or a disease that affects more than one body system (a systemic disease).

Talk to your healthcare provider if you have an itch (with or without a rash) that won't go away or if it interferes with your daily activities. You should also seek help if your rash is painful, blistering, or shows signs of infection.

Your healthcare provider will start with a careful history and perform a physical exam. They will examine your rash (if you have one) and look for signs of a more widespread problem.

You may need additional tests to identify what is causing your itch. These could include a complete blood count, HIV test, stool culture (to rule out parasites), or even a skin biopsy. They may also perform tests to assess how your liver, kidneys, or thyroid are functioning.

Treatments for Itchy Skin

The best way to stop an itch is to treat the cause. But sometimes, that takes time. Until the underlying problem is corrected, you may need treatment to control the itch and reduce the itch-scratch cycle.

Above all, do not scratch. Gently tapping your skin or applying cool cloths or ice packs to the itch can bring you some relief and avoid causing breaks in the skin that could get infected.

Treatments for itching may include medications as well as home remedies.

Medications

Some lotions, creams, and medications can help reduce itchiness.

Common treatments include:

• An oily moisturizer or emollient if your skin is dry or flaky
• Creams containing menthol to cool your skin or anti-itch ingredients such as crotamiton
• Mild steroid cream (usually for only a few days) for small, inflamed areas. Hydrocortisone cream is available over the counter, or your healthcare provider may prescribe a steroid cream
• Oral antihistamine tablets (such as Benadryl) to help control allergic reactions.
• Antidepressants may be prescribed if the above medications don't help
  

Home Remedies

If you have widespread itching, at-home treatments can be helpful. Regardless of what's causing your itchy skin, some simple steps at home can help improve your symptoms, prevent dry skin, and reduce the urge to itch. These include:

• Use oatmeal baths. Adding finely ground oatmeal to warm baths can soothe and moisturize skin.
• Don't take hot showers. Cooler, shorter showers are a better option.
• Use soap sparingly. Only apply soap to areas that need it, such as the groin, armpits, anal area, under the breasts, and other oily or dirty areas. Use soaps that are mild and free of fragrances or other additives.
• Moisturize. Apply a moisturizing cream immediately after bathing.
• Avoid dry air. Humidify your home to at least 40%, especially during dry, cold months.
• Avoid irritants. Wool, fiberglass, detergents, or other topical irritants can aggravate your skin and make you itch.
• Wear loose-fitting clothing. Keeping clothing away from skin can reduce irritation

If you continue to experience itchy skin, you should schedule an appointment with your healthcare provider.

Summary

An uncontrollable itch can be maddening, especially if you aren't sure why it is happening or how to treat it. Itchy skin—or pruritus—can have a variety of causes, from contact with a skin irritant (like wool) to a more serious condition, so it's important to understand the reason behind your need to scratch.

Talk to your healthcare provider if you have an itch or rash that impacts your daily activities, doesn't go away, worsens over time, or shows signs of infection. Your provider will be able to help you take steps to reduce or eliminate your symptoms and keep them from coming back.