Prurigo Nodularis

What is prurigo nodularis?

Prurigo nodularis (PN) is a skin condition that causes hard, raised bumps on your skin. The bumps are often dry and crusty on top. They’re extremely itchy, especially at night. You might only have a few bumps or a large collection of bumps in one area. Scratching the bumps can lead to bleeding or scarring.

Prurigo nodularis can develop anywhere on your body, but it’s often on your:

• Abdomen.
• Arms.
• Legs.
• Scalp.
• Shoulders.
• Upper back.

This condition is chronic, which means that it often lasts a long time, or gets better and comes back again (recurs).

Who gets prurigo nodularis?

Anyone can get prurigo nodularis, though it’s more common in:

• African Americans.
• Adults between ages 40 and 69.
• Women and people assigned female at birth.

Certain skin diseases can increase your risk of PN, including:

• Bullous pemphigoid.
• Cutaneous T-cell lymphoma.
• Eczema (atopic dermatitis).
• Keratoacanthomas (skin tumor caused by sun exposure).
• Lichen planus.
• Other types of prurigo.
• Psoriasis.
• Severely dry skin (Xerosis cutis).

Other health conditions that may increase your risk of PN include:

• Cancer.
• Certain bacterial, viral and parasitic infections.
• Diabetes.
• Gout.
• Human immunodeficiency virus (HIV).
• Iron deficiency.
• Kidney failure or chronic kidney disease.
• Liver disease.
• Lupus.
• Nervous system disorders.
• Some mental health disorders, like psychogenic pruritus (impulse to scratch at your skin due to a perceived itching sensation) or obsessive-compulsive disorder.
• Thyroid disease.

How common is prurigo nodularis?

PN affects about 72 out of every 100,000 people in the U.S. But it’s likely more common than these numbers suggest. It often appears alongside other skin conditions, and experts believe providers may sometimes miss it during diagnosis.

What are the symptoms of prurigo nodularis?

Prurigo nodularis symptoms include:

• Raised bumps on your skin, usually topped by a thick, dry crust. The bumps might be the same color as your skin. They can also be light pink, dark red, brown or black. The bumps might vary in size and depth. Sometimes, they affect both your epidermis (top layer of skin) and dermis (middle layer of skin).
• Intense itchiness.
• Sometimes, burning or stinging.

PN bumps might be categorized as:

• Nodules (larger than 1 centimeter in diameter and going into your epidermis).
• Papules (less than 1 centimeter in diameter and only on the surface of your skin).
• Plaques (shallow, scaly lesions that are more than 1 centimeter in diameter but don’t go beneath the surface of your skin).

What causes prurigo nodularis?

Prurigo nodularis isn’t contagious. It may result from too many nerve or immune cells in your skin. Other conditions may increase itchiness on your skin’s surface, so the bumps might appear from excessive scratching and irritation. Sometimes, medication — like certain types of chemotherapy — causes prurigo nodularis.

How is prurigo nodularis diagnosed?

A healthcare provider examines your skin. They check the size, color and location of the bumps. They’ll also ask how itchy the bumps are and if certain triggers increase the itchiness.

Make sure your provider knows about any other skin or health conditions you have, including allergies. This information can help them distinguish between PN and other disorders.

Tests for prurigo nodularis may include:

• Dermoscopy: Your provider uses a dermoscope (a handheld microscope with a light) to evaluate your skin. Dermoscopy provides a magnified view of your skin and doesn’t require any cuts.
• Blood and urine tests:A complete blood count, basic metabolic panel and urinalysis can help your provider identify health conditions like liver, thyroid or kidney disease.
• Biopsy:Your provider takes a skin sample using a razor, scalpel or other cutting tool. You receive a local anesthetic to numb your skin. The skin biopsy sample includes skin from your dermis and epidermis. They examine the sample in a lab under a microscope to check for abnormal cells or other signs of disease.

How is prurigo nodularis treated?

The most common treatments for mild prurigo nodularis include:

• Injections: You may receive an injection of medication directly into the skin lesions. Injections of corticosteroids (anti-inflammatory drugs) reduce inflammation and can help relieve pain, redness and itching right away.
• Topical treatments: You apply certain medications directly to your skin as creams or ointments. Calamine lotion is a common antihistamine (anti-itch medication). Your provider may also recommend topical corticosteroids, vitamin D or calcineurin inhibitors (immune system suppressants).

If injections or topical treatments aren’t effective, your provider may recommend:

• Cryotherapy:Cryotherapy uses liquid nitrogen to freeze off large or especially itchy skin lesions. Most people receive cryotherapy in combination with corticosteroid injections.
• Immunosuppressants:Immunosuppressants are drugs that prevent your immune system from overacting. You might receive this treatment if you have PN related to an autoimmune disorder, such as lupus or psoriasis.
• Phototherapy:Phototherapy uses ultraviolet (UV) light to reduce itchiness and help skin lesions heal. It works by calming immune cells that release histamines. Most people need several treatments.

How can I prevent prurigo nodularis?

There’s no way to prevent prurigo nodularis, but you can take steps to reduce itchiness, irritation and new PN flare-ups:

• Avoid the sun or wear sunscreen with an SPF (sun protection factor) of at least 30.
• Keep your fingernails trimmed short.
• Stay out of hot environments and avoid activities that may cause sweating.
• Use gentle cleansers and moisturizers on your skin.
• Wear long sleeves and gloves.

If skin lesions break open or bleed, be sure to apply antibiotic ointment and cover the lesions with clean bandages.

Does prurigo nodularis go away?

Sometimes, prurigo goes away on its own, but it’s a chronic skin condition that can last for several months or longer. The skin rash may clear up for a while and then come back. Identifying what triggers your flare-ups may help you avoid them in the future.

Complications from PN are rare, but open lesions can get infected. Healed lesions may leave scars or cause skin discoloration.

When should I contact my healthcare provider about prurigo nodularis?

Contact your healthcare provider if you notice any signs of infection, including:

• Discharge or pus draining from a lesion.
• Fever.
• Pain, tenderness or swelling around a lesion.
• Red or warm skin around a lesion.
• Red streaks around lesions.

What questions should I ask my healthcare provider about prurigo nodularis?

If you have PN, you may want to ask:

• Are there foods I should avoid with prurigo nodularis?
• Are there home remedies for prurigo nodularis?
• How can I reduce the risk of scarring?
• How can I relieve itching, especially at night?
• Is my prurigo nodularis the result of an underlying health condition?

A note from Cleveland Clinic

Prurigo nodularis can be difficult to treat. It often lasts several months or more and can come back after it gets better. It can be pretty frustrating to try one treatment after another, so be sure you have a dermatologist who listens to your concerns. In the meantime, you’ll want to keep your skin in the best condition possible, It’s hard not to scratch an itch, but scratching the bumps associated with prurigo nodularis can lead to infection and scarring. And more itchiness. Try to keep your skin cool and dry, and instead of scratching, try applying calamine lotion.