A patient presents with the oral lesion shown in the image. The white, lacy, reticular pattern on the buccal mucosa is characteristic of which of the following conditions?

Explanation

## Image Findings * **White, lacy, reticular patterns** on the buccal mucosa, consistent with **Wickham's striae**. * Erythematous (reddish) background, indicating inflammation. * Lesions appear non-scrapable. ## Diagnosis **Key Point:** The presence of **Wickham's striae** (white, lacy, reticular patterns) on the buccal mucosa is pathognomonic for **Oral Lichen Planus (OLP)**. Oral lichen planus is a chronic inflammatory mucocutaneous disease that commonly affects the buccal mucosa, tongue, and gingiva. The reticular form, as seen in the image, is the most common presentation and is characterized by asymptomatic interlacing white lines (Wickham's striae) on an erythematous background. Other forms include papular, plaque-like, atrophic, erosive, and bullous types. ## Differential Diagnosis | Feature | Oral Lichen Planus (Reticular) | Oral Candidiasis (Thrush) | Leukoplakia | Erythema Multiforme (Oral) | | :------------------ | :----------------------------- | :--------------------------------- | :---------------------------------------- | :----------------------------------------- | | **Appearance** | White, lacy, reticular (Wickham's striae) | Creamy white, cottage-cheese like plaques | Homogenous white plaque, sometimes verrucous | Bullae, erosions, target lesions (skin) | | **Scrapability** | Non-scrapable | Easily scrapable | Non-scrapable | Not typically scrapable, may have pseudomembrane | | **Underlying Mucosa** | Erythematous | Erythematous | Normal or erythematous | Ulcerated, hemorrhagic | | **Symptoms** | Often asymptomatic, sometimes burning | Burning, altered taste | Asymptomatic | Painful, burning, difficulty eating | ## Clinical Relevance **Clinical Pearl:** Oral lichen planus can be associated with **Hepatitis C virus (HCV) infection** and certain medications. It is considered a **premalignant condition**, with a small risk of malignant transformation (0.5-2%) to squamous cell carcinoma, especially the erosive and atrophic forms. Regular follow-up is crucial. ## High-Yield for NEET PG **High-Yield:** The classic **"6 P's"** of lichen planus are **Pruritic, Purple, Polygonal, Planar Papules and Plaques**. While these describe cutaneous lesions, the oral lesions are distinct but part of the same disease spectrum. **Key Point:** Histopathology shows a **sawtooth rete ridge pattern**, a **band-like lymphocytic infiltrate** at the dermo-epidermal junction (or epithelial-connective tissue interface in oral lesions), and **Civatte bodies** (apoptotic keratinocytes). ## Common Traps **Warning:** Do not confuse the non-scrapable, lacy white lesions of OLP with the easily scrapable white plaques of oral candidiasis or the more homogenous, non-scrapable white plaques of leukoplakia. The reticular pattern is key. ## Reference [cite:Robbins Basic Pathology, 10th Ed, Ch 19; Harrison's Principles of Internal Medicine, 20th Ed, Ch 62]