Prurigo nodularis is a chronic inflammatory condition of the skin that can cause firm, itchy, and painful bumps on the surface. According to the American Academy of Dermatology, PN usually begins with itchy skin. It can be localized or widespread.
The itching is intense enough to cause an uncontrollable urge to rub and scratch, which leads to more inflammation and itching. After six weeks, nodules that are not pus-filled appear in the area where you scratched.
Many (but certainly not all) of those developing prurigo nodular have another skin disorder that causes itchy, dry skin. This is according to Steven Feldman, MD, Ph.D., a dermatologist and researcher at Atrium Health Wake Forest Baptist, Winston Salem, in North Carolina.
Dr. Feldman says that rubbing and scratching enough can cause prurigo nodules if you suffer from eczema or Psoriasis. He says that even scratching insect stings may cause prurigo.
Prurigo nodularis: Symptoms and signs
According to AAD, the first sign of prurigo is itchy skin. Some people may also experience a burning sensation or stinging. Itching can occur in bursts or be constant.
Feldman says rubbing, scratching, or picking the skin can eventually lead to itchy, hard lumps. Yale Medicine states that bumps tend to appear in areas where it is easy to scratch.
- Arms and legs
- Abdomen
- Back, upper and lower
The nodules may range from a few microns to three centimeters in size and can be black, red, brown, or the same color as the rest of the skin.
Prurigo nodularis: Causes and risk factors
According to the National Organization for Rare Disorders, the exact cause of PN remains unknown. However, changes in the function and nerves of the skin could be linked with heightened itchiness, which triggers frequent scratching.
Researchers have identified several risk factors associated with prurigo nodularis. These include:
Age According to the AAD, PN is most common among people aged 50 and older.
Skin Conditions: According to Feldman, individuals with a history of atopic dermatitis, Psoriasis, or other skin disorders are more likely than others to develop prurigo nodular.
According to Yale Medicine, people with certain underlying conditions are more susceptible to prurigo nodularis. These include kidney failure, HIV infection, hepatitis C, parasitic and bacterial infections, thyroid problems, lymphoma, or liver diseases.
Race and ethnicity: Black people, particularly those with atopic dermatitis that flares up often, have a higher risk of prurigo nodularis. This is according to the AAD.
How Is Prurigo Nodularis Diagnosed?
Feldman says that dermatologists can diagnose prurigo nodularis from bumps in the skin. They should pay particular attention to those located near areas where they can be scratched and rubbed.
A dermatologist might need to perform a skin biopsy if you have multiple skin conditions. The biopsy is achieved by taking a sample of skin tissue and looking at it under a magnifying glass to check for changes in skin cells and tissues.
Blood tests are sometimes used to diagnose PN in people who have other diseases, like diabetes, hepatitis C and HIV, untreated.
Prurigo nodularis: Treatment and medication options
Feldman says there is no cure for the prurigo nodularis condition, but several treatments help break the cycle of itching, scratching, and itching again. They include:
- Corticosteroids: Feldman says that steroid creams and ointments may help to reduce inflammation and itching if there are only a few nodules. According to Yale Medicine, oral or injectable corticosteroids can be used for PN that is more severe.
- Antihistamines These medications can reduce itching.
- Feldman says that exposure to ultraviolet light (UV) can reduce inflammation and itching.
- Cryosurgery is a treatment option for itchiness and pain if other methods do not work. It’s not the first or second option for people with darker skin because it can result in light spots or scarring.
- Feldman says immunomodulatory drugs are prescribed in more severe cases or when nodules do not respond to other treatments. Dermatologists may prescribe immunosuppressive medications, like methotrexate and cyclosporin, to control inflammation. These medications can have long-term adverse effects on health, Feldman says.
- Other medications: Dermatologists may prescribe naltrexone or antidepressants. gabapentin and pregabalin.
Dupixent injection was the first treatment approved for prurigo nodularis by the U.S. Food and Drug Administration. Feldman says that Duplilumab has been proven to be highly effective and is already approved for atopic dermatitis.
Dupixent can be administered subcutaneously. A 300-milligram dose is issued every two weeks after the initial loading dose. According to FDA, in clinical trials, the drug caused significant improvement in itching and reduced/cleared nodules.
Lifestyle changes and complementary therapies
Feldman says it’s hard, but try not to scratch nodules. Feldman says that if you only have a few spots on your skin, a band-aid can be placed over them.
Yale Medicine offers some other tips for treating the itching-scratching cycle:
- When bathing, use mild soaps or no soap.
- Apply moisturizer at least three times per day.
- Spread over-the-counter lotions and creams to soothe skin and reduce itching, including capsaicin, pramoxine (a topical anesthetic), and products containing camphor, menthol, and phenol.
- Keep fingernails trimmed.
- Avoid accidental scratching by wearing gloves or mittens when sleeping.
A case report published in November 2021 by Clinical Cosmetic and Investigational Dermatology showed that four months’ worth of acupuncture therapy significantly reduced itch.
Prurigo nodularis: Prevention
There is no surefire way to prevent PN because the cause is unknown, and it’s unclear why some people have it while others do not.
According to the AAD, there are ways that you can prevent the cycle of itch-scratch from the beginning. Minimizing symptoms can be minimized by avoiding common triggers such as stress, heat and humidity, sweating or dryness, scented products, clothing, and clothes made from wool, polyester, cotton, or other rough fabrics.
Prurigo nodularis: Complications
Infection Scratching or rubbing nodules may cause infection. Infections can be characterized by swelling, discoloration or warmth, pus leaking through the skin, or pain.
If you notice any symptoms of infection, call your dermatologist immediately.
Scarring An article published in the journal JAMA Dermatology notes that when medication or self-care measures improve the prurigo nodularis itch, the nodules slowly heal but can leave scars on people with lighter and darker skin.
Who has Prurigo Nodularis, according to research and statistics?
According to NORD, Prurigo Nodularis affects a relatively small number of people. In the United States, it affects about 88,000. Anyone can develop PN, but the condition is more common among those aged 40-69. About 55 percent of those who develop PN are female, while 45 percent are male.
Prurigo Nodularis and Black Americans
According to NORD, PN occurs 3.4 times as often in Black Americans. According to JAMA Dermatology, black people with PN tend to have larger, darker, and firmer bumps. These dark spots can take months or even years to fade.
Prurigo nodularis:
Skin DiseasesOften, called Eczema Atopic Dermatitis, is caused by an overactive immune system. It causes the skin to be discolored, itchy and inflamed. According to a report in the Journal of the European Academy of Dermatology and Venereology, about half of people with PN also have a history of atopic dermatitis.
Other Chronic Conditions There are links between prurigo nodularis, kidney failure, HIV infection, hepatitis C, certain bacterial or parasitic infections, and thyroid disease. Some people with PN also have diabetes.
Anxiety Prurigo Nodularis has been linked to a variety of mental health problems. A study published in the Journal of Clinical and Aesthetic Dermatology found that nearly half of people with PN had some mental disorder. The most common were anxiety and depressive disorders.
Prurigo nodularis: How to Live with it
Feldman says that Prurigo Nodularis may cause emotional distress and discomfort, hurting the quality of life. People with PN can have difficulty sleeping or lack self-confidence. They may avoid social situations and miss school and work. Mental health problems may also be present.
AAD AAD states that PN can hurt a person’s mental and emotional health.