Overview 

What is Neurodermatitis? 

Neurodermatitis is a chronic skin condition characterised by intense itching and scratching. It typically affects one or two patches of skin, typically the wrists, neck, forearms, legs, and groin area.¹ Neurodermatitis symptoms typically intensify during rest periods or when the patient is sleeping. The urge to scratch often overwhelms these moments, leading to disrupted sleep patterns. It's not uncommon for individuals to unconsciously scratch or rub the affected areas while sleeping, sometimes even waking themselves up.¹ Without treatment, neurodermatitis can worsen over time, leading to a vicious cycle of intensifying symptoms. Persistent scratching causes the skin to thicken as a protective response, reducing bleeding and infections. However, this thickened skin paradoxically tends to itch more, further exacerbating the condition. As the itch-scratch cycle continues, some patients may develop a habit of unconscious scratching.²

Symptoms 

• The main symptom is intense itching, often on the neck, arms, legs, scalp, or genital areas¹
• Scratching leads to thick, leathery, discoloured patches of skin¹
• Scarring from scratching¹
• Pain
• When neurodermatitis affects the scalp, chronic itching and scratching can result in hair loss¹
• Open sores 
• Infections

Causes 

• The exact cause is unknown, but it often starts during times of stress, emotional trauma, anxiety, or depression¹
• Possible triggers include bug bites, tight clothing, and dry skin¹
• Other skin conditions, such as eczema and psoriasis, can occasionally lead to neurodermatitis¹
• An injured nerve²
• Sweating or heat could be a possible trigger²
• Allergies

Diagnosis 

• Typically diagnosed through physical examination and medical history³
• A skin biopsy may be performed to rule out other conditions, such as eczema and psoriasis³
• Blood Tests
• Skin swab tests are conducted to detect any infections¹
• Patch testing is carried out to help determine if an allergy is an underlying issue¹
• Fungal tests are used to identify skin disorders in the affected area and to rule out sexually transmitted infections¹

Prevalence 

• More common in adults between 30-50 years old¹
• Women are more likely to develop it than men, at a ratio of 2:1¹
• Individuals are at a higher risk of developing neurodermatitis if they have anxiety, suffer from obsessive-compulsive disorders, or have family members with a history of skin conditions, particularly eczema or contact dermatitis¹

Impacts on quality of life

• It can significantly disrupt sleep and daily activities due to constant itching¹
• It may cause anxiety and depression, further exacerbating symptoms¹
• In some cases, it can lead to skin infections, open sores, and scarring from excessive scratching¹

Overview of pharmacological treatments

Tropical treatments 

Corticosteroids

Topical corticosteroids are the most frequently used and effective topical medications for treating skin conditions like neurodermatitis.⁴ They come in various forms: creams, lotions, gels, mousses, ointments, tapes, bandages, and solutions. They are available in different strengths: mild, moderate, potent, and very potent.

They work by reducing inflammation, redness, and irritation in the skin.⁴ Ointments are generally best for dry skin conditions, while creams are preferred for wet and weepy skin.⁵The potency and type of corticosteroids should be chosen based on the severity of the condition and the area of the body being treated.

They reduce inflammation by inhibiting phospholipase A2, which produces inflammatory mediator.⁶ This suppresses the recruitment and activation of inflammatory cells (e.g., eosinophils, T cells, monocytes), decreasing adhesion molecule expression.⁷

Corticosteroids also affect metabolism and the central nervous system and have immunosuppressive effects.

Side effects: The risk of experiencing side effects depends on the type of steroid, the dose, the length of treatment, and the patient's age.

Common local side effects:⁴

• Burning or stinging sensation when first applied (usually improves with continued use)
• Skin thinning (atrophy)
• Stretch marks (striae), especially in the armpits or groin.
• Easy bruising and tearing of the skin.
• Enlarged blood vessels (telangiectasia)
• Increased hair growth in treated areas (hypertrichosis)
• Changes in skin colour (more noticeable in people with dark skin)
• Acne or worsening of existing acne.
• Rosacea

Less common but potentially serious side effects:⁴

• Worsening or spreading of skin infections
• Inflamed hair follicles (folliculitis)
• Contact dermatitis (allergic reaction to the corticosteroid)
• Periorificial dermatitis
• Steroid rosacea
• Topical steroid withdrawal symptoms upon discontinuation

Calcineurin inhibitors 

Calcineurin inhibitors are a class of immunosuppressive drugs that work by inhibiting the activity of calcineurin, a protein phosphatase that activates immune system T-cells.⁸ They treat inflammatory skin conditions like atopic dermatitis and neurodermatitis, particularly in sensitive areas where corticosteroids may not be suitable. They are useful treatments for chronic skin conditions without causing skin thinning, a common side effect of corticosteroids. It can be used on sensitive skin areas such as the face and neck.⁸

Common calcineurin inhibitors:⁸

• Tacrolimus: Used systemically (e.g., in organ transplantation) and topically (e.g., in skin conditions like atopic dermatitis and neurodermatitis)
• Pimecrolimus: Primarily used topically for skin conditions such as atopic dermatitis and neurodermatitis

Potential side effects:⁸

Local Side Effects: A burning or stinging sensation at the application site, skin irritation, and an increased risk of skin infections. Topical calcineurin inhibitors should not be used on infected skin and should be applied only to the affected areas.

Topical antihistamines 

Topical antihistamines block the action of histamine, a chemical released during allergic reactions causes itching, swelling, and redness. They are used to treat symptoms of allergic reactions, such as itching and inflammation. They are effective for conditions like atopic dermatitis, lichen simplex chronicus, and reactions to insect bites or contact with irritants like poison ivy.⁹

Diphenhydramine (Benadryl):⁹

Forms: Available as creams, gels, and sprays.

Usage: Applied to the skin to relieve itching from insect bites, minor cuts, burns, and rashes due to allergies or plants like poison ivy.

Doxepin (Zonalon, Prudoxin):⁹

Forms: Available as creams.

Usage: Used for treating itching associated with atopic dermatitis and lichen simplex chronicus.

Side Effects: Potential side effects include local irritation, burning, or stinging. Overuse can lead to systemic absorption and side effects like drowsiness (for antihistamines).¹⁰

Oral and injected medications

Doctors may recommend stronger oral or injected medications when topical treatments are insufficient to relieve symptoms. These are typically used for short periods to control symptoms, after which treatment usually shifts back to topical medications and at-home therapies. However, in severe cases , some medications may be prescribed for extended periods.¹⁵

Oral or injected immunosuppressants¹⁵

Function: Prevent the immune system from sending inflammatory responses to the skin, reducing itching, redness, and rash.

Administration: Taken orally once or twice daily, or injected into the skin.

Duration: Prescribed for weeks, months, or years depending on symptom severity and response.

Considerations: Dosage is determined based on age, symptom severity, rash location and extent, weight, and other medical conditions.

Oral corticosteroids¹⁵

Function: Powerful anti-inflammatory medications can quickly relieve symptoms.

Efficacy: Provide relief within hours or days.

Caution: Associated with more serious side effects than topical formulations, including high blood pressure, gastrointestinal problems, decreased bone density, and weight gain.

Usage: Generally reserved for severe outbreaks or as short-term treatment before starting long-term medications.

Oral antibiotics¹⁵

Indication: Prescribed when a skin infection develops due to broken skin from scratching or cracked rashes.

Duration: Typically limited to 7 to 14 days to prevent antibiotic resistance.

Side effects May include nausea, allergic reactions, and the potential development of antibiotic-resistant infections.

It's important to note that these systemic treatments are typically used under close medical supervision due to their potential side effects. Dermatologists carefully determine the choice of medication, dosage, and duration of treatment based on the individual patient factors and the severity of the condition. 

Other treatments

Phototherapy¹¹

• Phototherapy involves exposing the skin to specific wavelengths of light to reduce inflammation and itching.
• Common types include narrowband UVB and PUVA (psoralen plus UVA).
• It may be useful for widespread neurodermatitis that doesn't respond well to topical treatments.
• Treatment is typically administered 2-3 times per week in a clinical setting.

Psychological interventions¹²

• Stress and anxiety can exacerbate neurodermatitis, so psychological interventions can be beneficial
• Patients who use cognitive-behavioural therapy (CBT) may be able to control their stress levels and cut back on their scratching habits
• Relaxation techniques and mindfulness practices can help reduce stress-related flare-ups
• Support groups can offer both practical guidance for managing the condition and emotional support

Lifestyle modifications and skincare^13,14

• Keeping the skin moisturised is crucial. Regular use of emollients can help maintain skin barrier function
• Avoiding triggers such as certain fabrics, heat, or sweating can help prevent flare-ups
• Using mild, fragrance-free soaps and detergents can reduce skin irritation
• Maintaining a cool, humid environment can help prevent skin dryness
• Regular, gentle exercise may help reduce stress and improve overall well-being
• A balanced diet rich in anti-inflammatory foods may support skin health

Summary 

Neurodermatitis is a chronic skin condition characterized by intense itching and scratching, typically affecting one or two patches of skin. Treatment options include topical corticosteroids, calcineurin inhibitors, and antihistamines to reduce inflammation and itching. For severe cases, oral or injected medications such as immunosuppressants, corticosteroids, and antibiotics may be prescribed. Phototherapy, psychological interventions, and lifestyle modifications serve as adjunctive treatments. Management focuses on breaking the itch-scratch cycle and may involve a combination of medications, stress reduction techniques, and skincare practices. While challenging to treat, proper care and medical guidance can help patients effectively manage symptoms and improve their quality of life. Regular follow-ups with healthcare providers are essential to monitor treatment effectiveness and adjust as needed.