Lichen simplex chronicus (LSC) is a chronic skin condition characterized by thickened, leathery skin caused by persistent scratching or rubbing. It typically affects individuals with a history of eczema, allergies, or other pruritic (itchy) skin disorders. LSC is not a primary skin disease but rather a reaction to repeated mechanical irritation.
Causes and Risk Factors
The exact cause of lichen simplex chronicus is not a distinct dermatological disorder but results from prolonged scratching due to chronic pruritus. Some common triggers include:
- Underlying dermatological conditions: Atopic dermatitis, psoriasis, and xerosis (dry skin)
- Psychological factors: Anxiety, stress, and obsessive-compulsive behaviors
- External irritants: Fabrics, chemicals, soaps, and insect bites
- Neuropathic conditions: Nerve disorders causing localized pruritus
- Systemic diseases: Diabetes mellitus, liver disease, and kidney dysfunction
Symptoms and Affected Areas
Lichen simplex chronicus manifests as localized, thickened, and hyperpigmented plaques with an intense itch. The affected areas commonly include:
- Neck and nape
- Scalp
- Ankles and feet
- Wrists and forearms
- Genital and perianal regions
- Upper back
Clinical Features
- Lichenified plaques: Thickened, scaly, and hyperpigmented skin
- Intense pruritus: Worsens with stress and nighttime scratching
- Excoriations and fissures: May lead to secondary bacterial infections
- Koebner phenomenon: New lesions appear along areas of repeated trauma
Diagnosis
Clinical Evaluation
Diagnosis is primarily clinical, based on characteristic thickened plaques and history of chronic itching. The following tests may be conducted for confirmation:
- Dermoscopic examination: Reveals accentuated skin markings and excoriations
- Skin biopsy: Confirms epidermal hyperplasia, hyperkeratosis, and fibrosis
- Patch testing: Identifies allergic triggers
- Fungal and bacterial cultures: Rules out infections
Treatment and Management
Topical Therapies
- High-potency corticosteroids: Clobetasol or betamethasone to reduce inflammation
- Calcineurin inhibitors: Tacrolimus and pimecrolimus as steroid-sparing agents
- Moisturizers and emollients: Reduce skin dryness and prevent further irritation
Systemic Medications
- Oral antihistamines: Hydroxyzine and diphenhydramine for nighttime itch relief
- Anxiolytics and antidepressants: SSRIs or tricyclics for stress-related pruritus
- Immunosuppressants: In severe cases, cyclosporine or methotrexate
Lifestyle Modifications
- Avoid scratching triggers: Wear loose clothing and use hypoallergenic skincare products
- Behavioral therapy: Habit-reversal training to reduce compulsive scratching
- Stress management: Meditation, yoga, and cognitive-behavioral therapy (CBT)
Complications
- Secondary infections: Due to persistent scratching and excoriations
- Skin thickening and permanent discoloration: Long-term lichenification
- Psychosocial impact: Emotional distress and sleep disturbances
Prognosis and Long-Term Care
Lichen simplex chronicus can be managed effectively with proper treatment, but relapses are common. Ongoing skincare, stress management, and medical follow-ups help in preventing recurrence.
Lichen simplex chronicus is a challenging but manageable condition that requires a multifaceted approach. Addressing both dermatological and psychological factors is crucial for long-term relief. Early intervention and adherence to treatment plans significantly improve outcomes.
