Prurigo Nodularis Pictures & Causes

Understanding Prurigo Nodularis

Prurigo nodularis (PN) is a chronic skin condition characterized by itchy, firm nodules or bumps on the skin. Also known as neurodermatitis nodularis, PN often appears on the arms, legs, back or other areas that are frequently scratched or rubbed. While not life-threatening, prurigo nodularis can be extremely uncomfortable and significantly impact a person's quality of life.

What Causes Prurigo Nodularis?

The exact cause of PN is not fully understood, but it is considered an inflammatory dermatosis or skin inflammation. PN often occurs in people with underlying conditions that make the skin more sensitive, like atopic dermatitis. PN starts when something repeatedly rubs, scratches or picks at the skin, triggering the body's immune and inflammatory response. This creates small, itchy bumps that continue to be aggravated, forming harder, frustrated nodules that may ooze, crust or scar.

PN has a chronic, cyclical nature. The urge to scratch nodules further damages the skin, propagating the inflammatory cycle that causes more nodules to form. A variety of internal and external triggers can worsen and prolong this cycle, including:

• Stress and anxiety
• Skin dryness
• Skin infections
• Insect bites
• Allergies
• Skin injuries
• Friction from clothing and fabrics
• Temperature changes or sweat

PN often accompanies other inflammatory or autoimmune skin disorders like psoriasis or lichen simplex chronicus. It is also associated with psychological disorders like obsessive compulsive disorder (OCD). The constant need to scratch can be rooted in underlying psychological distress.

Signs and Symptoms

The most prominent symptoms of PN are:

• Itchy, firm nodules - Typically 0.2 to 1 cm in diameter. Ranges from skin-colored to red or purple nodules if inflamed. Can weep, ooze or crust if scratched open.
• "Picker's nodules" - Develops at sites of habitual rubbing, picking or scratching.
• Thickened, hyperpigmented skin - Darker, thick plaques around nodules or sites of repeated trauma.
• Excoriation - Visible scratch marks, scabs and abrasions from scratching.

Nodule distribution follows common scratching patterns. They frequently occur:

• On extensor surfaces like elbows, knees, lower legs, ankles
• Shoulders and upper back
• Anogenital area
• Upper arms, forearms, wrists
• Around the neck
• Lower back and buttocks

Patients may experience pruritus (itchiness) and pain. Sleep disturbance is common when nodules occur on the arms or legs. PN is typically symmetrical, developing on both sides of the body, especially as the condition progresses.

Diagnosing Prurigo Nodularis

There are no lab tests or imaging that can diagnose PN. Doctors will diagnose prurigo nodularis primarily based on a physical examination of the skin. They will look for the characteristic firm, symmetrical nodules on typical areas of the body prone to rubbing and scratching. The medical history is also important to understand the person's symptoms, triggers and any underlying disorders.

Skin biopsy is sometimes done to confirm PN or rule out other skin diseases like squamous cell carcinoma. Under the microscope, PN nodules show thickening of the epidermis skin layer along with hyperkeratosis (excessive accumulation of keratin). There may be signs of damage to superficial nerves.

It is also important to have other inflammatory or autoimmune skin disorders examined and addressed. Prurigo nodularis, atopic dermatitis and psoriasis have overlapping signs and symptoms. The severe itching and thick lesions of poorly controlled atopic dermatitis can lead to PN.

Prurigo Nodularis Treatment

While not curable, prurigo nodularis can be managed and controlled with appropriate treatment. The goals are to:

• Reduce inflammation and itch
• Prevent new nodule formation
• Allow existing nodules to resolve
• Prevent infection
• Avoid triggering or aggravating factors

Treatment typically involves a multi-pronged approach with topical medications, oral medications and phototherapy. The condition often requires continued, long-term management.

Topical Corticosteroids

Topical corticosteroids are usually the first line of treatment for prurigo nodularis. Applied directly on the skin, corticosteroid creams or ointments reduce inflammation and itching in the area. Products with higher potency, like clobetasol or halobetasol, are often prescribed for thick, stubborn nodules.

Topical corticosteroids carry risks if overused, including skin damage, so dosage and frequency must be monitored. Clinicians may alternate use with non-steroid treatments like topical calcineurin inhibitors.

Oral Antihistamines

Oral antihistamines like cetirizine or hydroxyzine can help reduce pruritus and the urge to scratch. Sedating antihistamines taken before bedtime may sufficiently control nighttime scratching to allow healing.

Phototherapy

Ultraviolet (UV) light therapy can dampen inflammation and immune responses in the skin. Phototherapy options for prurigo nodularis include:

• Narrow band UVB therapy
• Broadband UVB
• UVA1 phototherapy
• Excimer laser therapy

Exposure is done under medical supervision 1-3 times per week in a clinic setting. Phototherapy helps resolve psoriasis and other inflammatory skin disorders that may worsen prurigo nodularis.

Oral Immunosuppressants

For severe, widespread PN, oral immunosuppressants like cyclosporine may be prescribed. They work systemically to reduce abnormal immune responses and inflammation. Due to their significant side effects, immunosuppressants are mainly used for short periods to get severe PN under control.

Biologics

Injectable biologic drugs that target overactive immune signaling are emerging as effective PN treatments. Biologics like dupilumab or ixekizumab have proven effective for uncontrolled atopic dermatitis and also shown promise for reducing prurigo nodularis lesions.

Intralesional Corticosteroid Injections

Stubborn, thick nodules may be directly injected with corticosteroid medication. Triamcinolone acetonide is often used for intralesional steroid injections. The direct injection reduces inflammation and itching in recalcitrant lesions. However, multiple injections are often required.

Surgical Removal

In some cases, thick prurigo nodules or hypertrophic lesions may be surgically removed. This can provide rapid local relief. However, without addressing the underlying cause, new nodules may form again at the same site of surgical excision.

Home Remedies and Lifestyle Changes

There are several daily habits and self-care tips that can be beneficial for prurigo nodularis management:

• Moisturize frequently - Use gentle, fragrance-free moisturizers to hydrate dry skin.
• Avoid triggers - Prevent heat, sweat, dry skin, insect bites, irritating fabrics.
• Cold compresses - Apply wrapped ice packs to itchy areas to relieve burning sensation and urge to scratch.
• Keep nails short and smooth - Limit skin damage from scratching.
• Wear cotton gloves or socks - Protects hands and feet during sleep.
• Relaxation techniques - Reduce anxiety and stress that can worsen pruritus.
• Counseling - Therapeutic support to overcome psychological distress or urges to pick.

Patients with atopic dermatitis, psoriasis or other inflammatory conditions should properly manage them to prevent flares and complications like PN.

What Does Prurigo Nodularis Look Like?

The characteristic appearance of prurigo nodularis is firm, round or oval-shaped nodules that form on the skin. The nodules can vary in size, ranging from a few millimeters to over a centimeter in diameter. They may be skin-toned, pink, red or dark purple.

These prurigo nodularis photos provide examples of how PN nodules typically look:

Early PN Nodules

Early prurigo nodularis lesions start as small, mildly inflamed and raised bumps that resemble insect bites or papules. There is often evidence of scratching like excoriations, scabs, crusting and hyperpigmentation:

[Insert 2-3 small sized images demonstrating early PN nodules]

Established PN Nodules

As the condition progresses, the nodules become larger, more defined and firmer. The nodule surface can appear uneven, with crusting or scaling, especially if continuously scratched:

[Insert 2-3 medium sized images showing established nodules]

Advanced PN Nodules

Over time, untreated PN nodules become much thicker and elevated, with a rough surface. They are more likely to weep fluid, bleed or scab from repeated irritation and scratching:

[Insert 2-3 large sized images displaying advanced nodular lesions]

Distribution Patterns

Prurigo nodularis often occurs bilaterally in symmetrical patterns following habitual scratching or irritation. Common nodule patterns include:

• Arms - outer surface of forearms in roughly linear patterns
• Legs - front of shins, knees, ankles and feet
• Posterior neck and upper back - within reach of scratching hands
• Face - cheeks, chin, forehead and scalp

[Insert 2-4 images demonstrating distribution on arms, legs, back, etc.]

Treating Itchy, Painful Nodules

Prurigo nodularis is notoriously stubborn and difficult to treat effectively. The nodules often return after treatment due to the chronic nature of the condition. However, there are medications that can relieve PN symptoms and potentially clear lesions.

Corticosteroids

Corticosteroids are the mainstay treatment for reducing inflammation that drives prurigo nodularis. Steroids come in many potencies and formulations:

• Topical corticosteroids - Creams, ointments, gels, sprays and lotions applied to the skin. Moderate to very high strength preparations are used.
• Intralesional injections - Steroids injected directly into tough nodules. Triamcinolone acetonide is commonly used.
• Oral corticosteroids - Short courses of oral steroids like prednisone may be tried for severe, extensive PN.

While effective, long-term steroid use carries risks like skin damage and high blood glucose. Steroid dosage and frequency must be carefully tapered.

[Insert 1-2 pictures of topical steroids]

Antihistamines

Oral antihistamines help control pruritus and the urge to scratch. First generation antihistamines like hydroxyzine or diphenhydramine provide sedation for nighttime relief. Non-drowsy antihistamines like fexofenadine can treat daytime itch.

[Insert 1-2 images of antihistamine products]

Phototherapy

Ultraviolet (UV) light therapy is effective for certain types of eczema and pruritic skin diseases. It can help resolve PN lesions and reduce itching. Phototherapy options include:

• Narrowband UVB
• Broadband UVB
• UVA1 therapy
• Excimer laser

Treatment involves standing in a specialized full body cabinet or having a handheld device applied to nodules. Sessions occur 1-3 times per week in a medical office.

[Insert 1-2 pictures of phototherapy equipment]

Biologics

Biologic drugs are on the horizon as effective PN treatments. Biologics like dupilumab act on immune system pathways involved in multiple inflammatory skin diseases. Clinical trials are underway exploring biologics for refractory prurigo nodularis.

[Insert 1-2 images of biologic medications]

Preventing Prurigo Nodularis Flare-ups

While prurigo nodularis cannot be permanently cured, the following self-care measures can help prevent flare-ups and minimize symptoms:

• Apply moisturizer frequently - Hydrating the skin prevents dryness and itching.
• Keep fingernails trimmed short - Minimizes skin damage from scratching.
• Wear gloves or socks at night - Creates a barrier against scratching.
• Identify and avoid triggers - Things like fabrics, foods, pets, or seasonal allergies that worsen PN.
• Apply cold compresses - Ice packs can temporarily soothe itching.
• Take antihistamines as needed - Helps control pruritus.
• Practice stress management - Anxiety and tension can worsen PN.
• Consider counseling - Helps overcome the urge to pick at skin.

Successfully controlling associated inflammatory skin conditions like atopic dermatitis is also important to prevent the development of prurigo nodules.

[Insert 1-2 images demonstrating prevention tips]

The Takeaway

Prurigo nodularis is a frustrating chronic skin disorder consisting of intensely itchy nodules on the skin. The nodules typically occur on arms, legs, the neck and body as a result of repeated rubbing, picking and scratching. While not curable, prurigo nodularis can be managed with topical steroids, antihistamines, phototherapy and other medications under a dermatologist's care. Preventing flare-ups relies on hydrating the skin, avoiding triggers, and controlling underlying inflammatory skin diseases.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.