L43.3

Clinical Causes: Immune system dysfunction, where the body's immune response mistakenly targets skin and mucous membranes. Genetic predisposition, with a family history potentially increasing risk. Triggering factors such as certain medications, dental fillings, or systemic illnesses. Exposure to environmental irritants or allergens. Viral infections, notably hepatitis C, have been associated with lichen planus. Psychological stress may also contribute to the development or exacerbation.

Key Symptoms: Itchy, flat-topped, polygonal, shiny, purple or reddish skin lesions. Lesions commonly appear on wrists, ankles, lower back, and inside the mouth. Lacy white lines, known as Wickham's striae, often visible on the surface of the lesions. Erosions or ulcerations in mucous membranes, particularly in the mouth. Pain, burning, or soreness in affected areas, especially when mucous membranes are involved. Persistence of lesions for weeks to months with possible periodic flare-ups. Potential for scaling or crusting in skin lesions.

Diagnosis Path: Diagnosis primarily involves a thorough clinical examination, where healthcare professionals assess the characteristic appearance of skin and mucous membrane lesions. A skin biopsy may be performed to confirm the diagnosis, revealing specific histopathological features such as a band-like lymphocytic infiltrate and sawtooth appearance of the rete ridges. Additional tests, including direct immunofluorescence, may help differentiate lichen planus from other skin conditions. Oral or mucous membrane involvement might require specific assessments for extent and severity.

Treatment Protocols: Management focuses on alleviating symptoms, reducing inflammation, and preventing complications. Common approaches include: - Topical corticosteroids to decrease inflammation and itching. - Systemic corticosteroids in severe or widespread cases. - Immunosuppressive agents like hydroxychloroquine or tacrolimus for resistant cases. - Oral antihistamines to relieve itching. - Good oral and skin hygiene practices. - Identifying and avoiding potential triggers or irritants. - Phototherapy may be considered in some cases. Patients are advised to consult healthcare providers for personalized treatment plans, as effective management depends on the severity and distribution of lesions.