Prurigo nodularis: Diagnosis and treatment

How do dermatologists diagnose prurigo nodularis?

Your dermatologist can often diagnose prurigo nodularis by examining the itchy bumps and patches on your skin.

If you have more than one skin condition, your dermatologist may need to scrape off a bit of skin or perform a skin biopsy. The skin your dermatologist removes will be examined under a microscope. This close-up view helps your dermatologist give you an accurate diagnosis.

Both a skin scraping and a skin biopsy can be performed during your appointment while you remain awake. A scraping is exactly what it sounds like. Your dermatologist scrapes off a bit of skin. During a skin biopsy, your dermatologist numbs the area and then removes a small amount of skin.

During your appointment, your dermatologist will also ask questions. This helps your dermatologist learn how the itch and bumps affect your life, whether you may have another condition, and important information that can affect your treatment plan.

Because people who develop prurigo nodularis may have another disease, including diabetes, hepatitis C, and untreated HIV, you may need blood tests.

If you have prurigo nodularis, your dermatologist will create a treatment plan tailored to your needs.

Prurigo nodularis may be the first noticeable sign of another disease like lymphoma or untreated HIV

That’s why dermatologists give patients who have prurigo nodularis a thorough exam, order medical tests, and sometimes refer a patient to another medical doctor.

How do dermatologists treat prurigo nodularis?

Treatment often begins before you have the results of your tests. That’s because prurigo nodularis is often treated separately from other conditions — even when another condition causes intensely itchy skin.

The goal in treating prurigo nodularis is to stop the itch, so that your skin can heal. To do this, a treatment plan may include one or more of the following.

Anti-itch emollient: Applied to the skin, this can reduce the urge to scratch. It also helps to soften and flatten the bumps and patches.

Itch relief medication (apply to your skin): Your dermatologist may recommend applying menthol, phenol, pramoxine, or capsaicin cream to help relieve the itch. These are available without a prescription. If you need a stronger medication, your dermatologist may prescribe calcipotriol or another medication.

Medication to control inflammation (apply to your skin): Your dermatologist may prescribe one or more of these medications, which you can apply at home: Corticosteroid, pimecrolimus, tacrolimus, or calcipotriol.

Medical tape coated with a corticosteroid: Covering itchy bumps and patches with this tape can help your skin absorb more of the medication. The tape has two more advantages. It can help flatten the bumps and patches. Wearing the tape also puts a protective layer between your nails and your skin, so you cannot directly scratch the bumps and patches.

Cryosurgery: If other treatments fail to relieve the itch and pain, cryosurgery may be an option. However, if you have a dark skin tone, cryosurgery is not a first or second option for treating prurigo nodularis. On darker skin tones, cryosurgery can cause noticeable light spots, scaring, or both. Should the prurigo nodularis fail to go away with other treatments, your dermatologist may talk with you about whether cryosurgery is an option for you.

When cryosurgery is part of your treatment plan, your dermatologist can perform this procedure during an office visit. You remain awake the entire time.

During cryosurgery, your dermatologist will apply a very cold substance like liquid nitrogen to the bumps and patches. Freezing helps to reduce the itch and flatten the prurigo nodularis.

When cryosurgery is used to treat prurigo nodularis, most patients need between two and four treatments. After each cryosurgery treatment, you may see crusting or a blister on your treated skin. This is normal and expected.

Injections of a corticosteroid: If you have a bump or patch that isn’t going away with treatment, your dermatologist may inject the area with a corticosteroid. This injection can relieve the itch and flatten the bump or raised patch.

This type of treatment can only be used on a few bumps or patches.

Phototherapy (also known as light therapy): Studies have shown that this type of treatment can effectively treat prurigo nodularis. Your dermatologist may prescribe phototherapy if you need stronger treatment than you can get from applying medications to your skin — or you have bumps and plaques on large areas of your skin.

Phototherapy is typically prescribed by a dermatologist

This non-invasive treatment exposes you to a prescribed amount of ultraviolet (UV) light for a precise amount of time.

If your dermatologist recommends phototherapy, you must be able to go to your dermatologist’s office or a phototherapy treatment center two to three times per week for a number of weeks.

The excimer laser is a type of phototherapy. For some patients, this laser can effectively treat a stubborn bump or patch of prurigo nodularis that just won’t go away. Research shows that it can work when other treatments fail.

Medication that works throughout your body: If you have widespread or severe prurigo nodularis, your dermatologist may include this in your treatment plan.

One medication that has been used for years to treat prurigo nodularis is an antihistamine that makes you sleepy. It can help prevent itching while you’re asleep.

Taking an antidepressant medication can help relieve the itch while you’re awake.

The medications methotrexate and thalidomide have also been used for years to help heal the skin.

Newer medications that can be effective include dupilumab, nemolizumab (a newer medication designed to break the itch-scratch-itch cycle), gabapentin, or aprepitant.

All medications that work throughout your body are powerful and come with possible side effects.

Help dealing with anxiety, depression, and other feelings: Having prurigo nodularis can be tough. Some people say that the frequent itch and scratching can take an emotional toll on their lives. They may feel less confident, stop getting together with people, or miss time from work or school.

Getting psychological counseling can be helpful if this disease is taking an emotional toll.

Self-care is an essential part of treatment

Following a self-care plan can improve how well treatment works and how well you feel. You’ll find the self-care that dermatologists recommend at: Prurigo nodularis: Self-care.

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References
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Huang AH, Williams KA, et al. “Prurigo nodularis: Epidemiology and clinical features.” J Am Acad Dermatol. 2020;83(6):1559-65.

LeCourt AP, “Prurigo nodularis.” In: Medscape (Elston DM., Ed.) Last updated 11/13/2020. Last accessed 7/23/2021.

Legat FJ, Weisshaar E, et al. “Pruritus and dysesthesia.” In: Bolognia JL, et al. Dermatology. (4th edition). Mosby Elsevier, China, 2018: 115-6.

Leis M, Fleming P, et al. “Prurigo nodularis: Review and emerging treatments.” Skin Therapy Lett. 2021;26(3):5-8.

Qureshi AA, Abate LE, et al. “A systematic review of evidence-based treatments for prurigo nodularis.” J Am Acad Dermatol. 2019;80(3):756-64.

Williams KA, Huang AH, et al. “Prurigo nodularis: Pathogenesis and management.” J Am Acad Dermatol. 2020;83(6):1567-1575.

Yosipovitch G. “Prurigo nodularis: New treatments on the horizon.” J Am Acad Dermatol. 2020;82(4):1035-6.

Written by:
Paula Ludmann, MS

Reviewed by:
Shari Lipner, MD, PhD, FAAD
J. Klint Peebles, MD, FAAD
Caroline Robinson, MD, FAAD

Last updated: 9/14/21