Prurigo nodularis: Overview

Prurigo nodularis on a patient’s leg

This disease causes hard, itchy bumps on the skin. You may see bumps that are red, pink, the color of your skin, or brownish black.

Before you see the bumps of prurigo nodularis, the skin is often intensely itchy. You may have one or two small areas of itchy skin, or the itch may be widespread. The itch may come in short, intense bursts or be present most of the time.

When the skin itches, it causes an uncontrollable urge to scratch and rub. After about six weeks, hard bumps called nodules appear where you’ve been scratching and rubbing.

The bumps are also intensely itchy. The frequent scratching can cause scrapes and tears on the skin. Some people scratch until the itchy bumps break open and bleed or the skin feels too painful to touch. The open and injured skin can become infected.

The scratching can cause more bumps and thick, scaly raised patches. The skin tends to feel extremely dry and inflamed. This dry, inflamed skin also itches, which leads to more scratching.

Why some people develop prurigo nodularis isn’t fully understood. Many who get this disease already have another condition that causes extremely itchy skin like atopic dermatitis, stasis dermatitis, scabies, extremely dry skin, or bullous pemphigoid. All of these conditions can cause repeated itching and scratching, which dermatologists call the itch-scratch-itch cycle.

Treatment for prurigo nodularis focuses on breaking this itch-scratch-itch cycle. If scratching has become something that you do without thinking about it, breaking this cycle can take time.

When dermatologists create a treatment plan for prurigo nodularis, the plan often includes medication, skin care, and tips to help you stop scratching.

Treatment takes time, and no one treatment works for everyone.

Researchers continue to study the itch-scratch-itch cycle and prurigo nodularis so that they can develop more effective and long-lasting treatments for both.

To get the best outcome from treatment, dermatologists recommend starting treatment soon after the itchy bumps appear. You can see how prurigo nodularis can progress without treatment and the different ways that it may appear on the skin at: Prurigo nodularis: Signs and symptoms.

Images
Image 1: Used with permission of the Journal of the American Academy of Dermatology:

• J Am Acad Dermatol; 2001;44:471-8.

Image 2: Used with permission of the American Academy of Dermatology National Library of Dermatologic Teaching Slides.

References
Elmariah S, Kim B, et al. “Practical approaches for diagnosis and management of prurigo nodularis: United States expert panel consensus.” J Am Acad Dermatol. 2021;84(3):747-60.

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 May;26(3):5-8.

Mullins TB, Sharma P, et al. “Prurigo nodularis.” In: StatPearls [Internet] Treasure Island (FL): StatPearls Publishing; 2021 Jan.

Rinaldi G. “The itch-scratch cycle: A review of the mechanisms.” Dermatol Pract Concept. 2019;9(2):90-7.

Silverberg JI. “Nummular eczema, lichen simplex chronicus, and prurigo nodularis.” In: Kang S, et al. Fitzpatrick’s Dermatology. (9th edition) McGraw Hill Education, United States of America, 2019:388-92.

Ständer S, Luger T, et al. “Treatment of prurigo nodularis with topical capsaicin.” J Am Acad Dermatol. 2001;44(3):471-8.

Yosipovitch G and Kwatra SG. “Itch associated with systemic disorders.” In: Living with itch: A patient’s guide. The Johns Hopkins University Press. United States, 2013:75.

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