Neurodermatitis · What Is It, Causes, Treatment, and More

Neurodermatitis, also often known as lichen simplex chronicus (LSC), is a localized skin condition involving repeated itching and scratching. The repeated scratching can cause the development of a characteristic plaque, or  thickening of the skin, known as lichenification. 

The exact cause of neurodermatitis is unknown, but research suggests that environmental factors, systemic disorders, and psychological factors may all play roles. Environmental skin irritants, such as tight clothing or a bug bite, may cause localized itching that initially triggers the persistent, repetitive scratching that characterizes neurodermatitis. The inciting itchiness could also be due to eczema, a group of skin conditions characterized by itchy, dry skin. Other systemic diseases -- such as psoriasis, which is a chronic autoimmune disease that causes skin inflammation, and lichen planus, an immune-mediated condition that presents as a skin rash -- can also cause persistent skin irritation. Finally, although neurodermatitis is generally caused by underlying environmental or skin factors, it is also often coupled with psychiatric disorders (e.g., obsessive compulsive disorder, anxiety, depression) that feature repetitive behaviors or psychological rumination. Neurodermatitis can easily become a chronic, debilitating condition. As the individual scratches the irritated area, it tends to become progressively irritated and itchier, creating a continuous cycle of scratching and itching that can eventually lead to skin thickening. 

Neurodermatitis is fairly common, affecting more than 10% of the population worldwide. Diagnosis of neurodermatitis is twice as common for females as it is for males. A diagnosis of neurodermatitis is reported most often in people 30 to 50 years old. It is relatively uncommon in children. 

Neurodermatitis is characterized by a well-defined and thickened plaque, which appears as an elevated patch of skin that is usually linear or oval in shape. Neurodermatitis plaques most commonly occur in a single location, typically on areas of the skin that are easily accessible, such as the neck, testicles, external parts of the female genitalia (i.e., vulva), wrists, forearms, lower legs, and the back of the scalp. Affected areas are typically pruritic, or markedly itchy, and they are frequently dry, leathery, and discolored. Some affected areas may appear darker than others. Often, the skin will show residual marks of scratching as well. Persistent scratching can lead to wound formation and subsequent skin infections. Finally, the constant itching associated with neurodermatitis can affect the individual’s sleep and quality of life. 

Diagnosis usually involves collecting the individual's history of intense itching and scratching and conducting a thorough physical exam. Skin scraping, a procedure in which superficial, dead layers of the skin are obtained and analyzed, may assist in ruling out other potential diagnoses, specifically a fungal infection. A skin biopsy, or the removal of a sample of skin for testing, is sometimes used to confirm diagnosis of neurodermatitis. 

The shape of the plaques can also assist in differentiating neurodermatitis from similar conditions. Prurigo nodularis, another skin condition that induces itching and scratching, produces round nodules, which present as localized swelling of the skin and differentiate prurigo nodularis from neurodermatitis. Nummular eczema, also known as discoid eczema, is another condition with a similar presentation to neurodermatitis, but the plaques nummular eczema produces are coin-shaped rather than linear. 

The aim of neurodermatitis treatment is to relieve itching and help the individual stop scratching. When neurodermatitis is due to an underlying cause, such as eczema or psoriasis, treatment should be targeted at resolving the underlying condition. Individuals with psoriasis or eczema may benefit from the use of immunosuppressive medications, such as oral corticosteroids (e.g., methotrexate, azathioprine). These medications can minimize inflammation, which plays an important role in the symptoms associated with these conditions. 

In cases associated with psychological conditions, psychotherapy may be recommended, particularly cognitive behavioral therapy (CBT) or habit reversal therapy. Additionally, antidepressant medications (e.g., amitriptyline, nortriptyline, duloxetine) may be prescribed.

In many cases, topical steroids may be prescribed to treat the itching. After application of a topical steroid, the individual may cover the area of skin for a couple of hours to discourage scratching. Steroid injections in the affected area are another treatment. If the persistent itching and scratching interferes with the individual’s ability to sleep, certain antihistamines (e.g., cetirizine) or tricyclic antidepressants (e.g., amitriptyline) may be prescribed to reduce itching and increase sleepiness. 

Lifestyle changes that may improve neurodermatitis symptoms include wearing loose-fitting clothes, holding cool compresses to the affected areas to relieve itching, and applying over-the-counter moisturizers. Moisturizing reduces skin dryness, which may decrease the desire for scratching, and some moisturizers contain colloidal oatmeal, which may protect against irritants.

Neurodermatitis, also known as lichen simplex chronicus, is a localized skin disorder characterized by chronic itching and scratching that leads to skin thickening, or lichenification. Lichenification presents as a thick patch, or plaque, of skin in one or more locations on the body. Plaques are most commonly found in areas that are easily accessible for scratching, namely the scalp, neck, testicles, vulva, wrists, forearms, and lower legs. The exact cause of neurodermatitis is unknown; however, the continuous cycle of scratching and itching can arise due to an external factor that irritates the skin,  like tight clothing or a bug bite. The primary itch can also occur as a result of certain skin conditions, including eczema or psoriasis. In some cases, neurodermatitis can also be associated with anxiety, depression, or obsessive compulsive disorder. Neurodermatitis is typically diagnosed by conducting a thorough physical examination and considering the individual’s history of intensive itching and scratching. The treatment plan for neurodermatitis involves treating the underlying cause and relieving itchiness. Recommendations to reduce itchiness may include medication (e.g., steroids, antihistamines) and lifestyle changes (e.g., wearing loose-fitting clothing, applying cold compresses).