Overview

Lichen Simplex Chronicus (LSC) is a chronic skin condition characterized by thickened, leathery patches of skin caused by repetitive scratching or rubbing. It is not a primary skin disease but rather a reaction to persistent itching (pruritus) from various underlying causes. The constant cycle of itching and scratching leads to skin changes, including hyperpigmentation, scaling, and lichenification (thickened skin with exaggerated skin lines). While LSC is not life-threatening, it can significantly affect quality of life due to discomfort and cosmetic concerns. Effective treatment focuses on breaking the itch-scratch cycle and addressing any underlying causes.

Causes

LSC is triggered by chronic scratching, which may originate from multiple underlying causes:

• Chronic skin conditions: Eczema, psoriasis, and atopic dermatitis commonly lead to persistent itching.
• Dry skin (xerosis): Especially common in colder climates or aging individuals.
• Allergic reactions: Allergies to fabrics, soaps, or environmental allergens can cause itching.
• Insect bites: Persistent scratching of insect bites can evolve into LSC.
• Fungal infections: Long-standing fungal infections may provoke LSC.
• Psychological factors: Stress, anxiety, and psychological conditions like obsessive-compulsive disorder (OCD) may lead to habitual scratching.
• Nerve disorders: Conditions like neuropathy can cause abnormal sensations leading to scratching.

Symptoms

The hallmark symptom of Lichen Simplex Chronicus is persistent itching and its effects on the skin:

• Intense itching: Worsens during periods of stress or at night, often leading to habitual scratching.
• Thickened, leathery skin patches: Resulting from chronic scratching or rubbing.
• Hyperpigmentation: Affected areas may appear darker than surrounding skin, especially in individuals with darker skin tones.
• Red or violaceous plaques: In lighter skin tones, the patches may appear reddish or purplish.
• Dry, scaly skin: The affected patches often have a rough, scaly surface.
• Well-demarcated borders: The patches are usually clearly defined and located in accessible areas for scratching.
• Common locations: Neck, scalp, wrists, forearms, ankles, and genital area.

Diagnosis

Diagnosis of Lichen Simplex Chronicus is primarily clinical, based on history and physical examination:

• Medical history: Assessment of itching patterns, triggers, and predisposing conditions.
• Physical examination: Identification of classic thickened, hyperpigmented plaques with visible scratch marks.
• Skin biopsy: Rarely needed but may be performed to rule out other skin conditions; shows characteristic thickened epidermis and inflammatory cells.
• Investigations for underlying causes: Tests for fungal infections, allergies, or other dermatologic conditions may be considered.

Treatment

The main goal of treatment is to stop the itch-scratch cycle, promote skin healing, and manage any underlying causes:

• Topical corticosteroids: High-potency steroids are used to reduce inflammation and itching.
• Antihistamines: Oral antihistamines can help relieve itching, especially at night.
• Moisturizers: Emollients reduce dryness and soothe irritated skin.
• Calcineurin inhibitors: Topical tacrolimus or pimecrolimus may be used in sensitive areas to avoid steroid side effects.
• Occlusive therapy: Covering the affected area with dressings helps prevent scratching and enhances treatment effectiveness.
• Antibiotics: Prescribed if there is a secondary bacterial infection due to scratching.
• Treatment of underlying conditions: Addressing eczema, fungal infections, or psychological triggers is essential for long-term control.
• Behavioral therapy: Cognitive-behavioral therapy (CBT) or habit reversal therapy may help individuals with compulsive scratching behavior.

Prognosis

The prognosis of Lichen Simplex Chronicus is generally favorable with appropriate treatment:

• Symptom control: Most individuals experience significant improvement with proper management of itching and inflammation.
• Chronic tendency: LSC is a chronic condition prone to recurrences, especially if triggers are not addressed.
• Risk of scarring: Long-standing cases may result in permanent skin thickening or color changes even after resolution of active symptoms.
• Quality of life: With consistent treatment and good skin care, most patients can lead normal, comfortable lives without significant impact.

Ongoing attention to skin care, stress reduction, and management of underlying causes are key to preventing relapses of Lichen Simplex Chronicus.