Lichen planus

Lichen planus is a chronic inflammatory condition that affects the skin, mucous membranes, hair, and nails. It is characterized by itchy, flat-topped, purplish lesions on the skin and white patches or streaks in the mouth. The exact cause is unknown, but it is thought to involve an abnormal immune response.

Key Points about Lichen Planus

1. Etiology and Risk Factors:

   • The exact cause of lichen planus is not well understood, but it is believed to be an autoimmune disorder where the body's immune system attacks its own tissues.
   • Possible triggers include certain medications, infections (such as hepatitis C), and allergens. Stress and genetic factors may also play a role.

2. Clinical Presentation:

   • Cutaneous Lichen Planus: Characterized by pruritic (itchy), polygonal, flat-topped, purple papules and plaques. Common sites include the wrists, lower back, and ankles.
   • Oral Lichen Planus: Presents as white, lacy patches (Wickham striae) or painful sores on the mucous membranes inside the mouth. It can also affect the tongue, gums, and inner cheeks.
   • Genital Lichen Planus: Affects the genital mucosa, causing discomfort and lesions.
   • Lichen Planopilaris: Affects the scalp, leading to hair loss (alopecia).
   • Nail Lichen Planus: Can cause ridging, thinning, and loss of nails.

3. Diagnosis:

   • Diagnosis is primarily clinical, based on the characteristic appearance of lesions.
   • A skin or mucosal biopsy may be performed to confirm the diagnosis and to rule out other conditions.
   • Direct immunofluorescence can help to detect specific immune deposits in the tissue.

4. Management and Treatment:

   • There is no cure for lichen planus, but treatments can help manage symptoms and reduce the severity of lesions.
   • Topical Treatments: Corticosteroids are the first line of treatment to reduce inflammation and itching. Calcineurin inhibitors (like tacrolimus) may also be used.
   • Systemic Treatments: In severe cases, systemic corticosteroids, retinoids, or immunosuppressive agents (such as methotrexate or cyclosporine) may be prescribed.
   • Phototherapy: UV light therapy can be beneficial for widespread skin involvement.
   • For oral lichen planus, maintaining good oral hygiene, avoiding spicy or acidic foods, and using corticosteroid mouthwashes or gels can help.

5. Prognosis:

   • Lichen planus is a chronic condition that may persist for months to years.
   • While it often resolves on its own, it can recur and sometimes becomes a long-term issue.
   • Regular follow-up is important to manage symptoms and monitor for potential complications, such as the rare transformation of oral lichen planus into oral squamous cell carcinoma.

6. Prevention and Lifestyle Adjustments:

   • Avoiding known triggers, managing stress, and maintaining good general health can help reduce the frequency and severity of flare-ups.
   • Regular dental check-ups and practicing good oral hygiene are particularly important for those with oral lichen planus.

Summary

Lichen planus is a chronic inflammatory disease that affects the skin, mucous membranes, hair, and nails. It presents with distinctive purplish, itchy lesions on the skin and white patches or sores in the mouth. While the exact cause is unknown, it is thought to be related to an abnormal immune response. Diagnosis is based on clinical features and sometimes a biopsy. Management includes topical and systemic treatments to reduce inflammation and manage symptoms. The condition is chronic but can be controlled with appropriate treatment and lifestyle adjustments. Regular monitoring is essential to manage the disease and prevent complications.