Lichen Planus
Lichen planus is a chronic, T cell–mediated inflammatory disease marked by flat-topped, many-sided, purple, very itchy bumps. It develops when T lymphocytes attack the keratinocytes in the basal layer of the epidermis, causing programmed cell death (apoptosis). Beyond its effect on appearance, the condition can seriously affect quality of life because of intense itching, or burning pain where mucous membranes become eroded.
At Haute-Derma, our main goals are to bring active disease under control quickly and to prevent long-lasting post-inflammatory dark marks.
How Lichen Planus Is Diagnosed
Diagnosis at Haute-Derma combines clinical experience with technology that examines the skin's fine structure:
- The "6 P" rule: Lesions are assessed for six features: planar (flat), purple, polygonal, pruritic (itchy), papules, and plaques.
- Dermoscopy: We look for Wickham striae, a fine, lacy network of white lines on the surface of the bumps and the single most telling sign of lichen planus.
- Examining mucous membranes, nails, and scalp: A careful check of the mouth, the nails (looking for V-shaped splitting), and the scalp (to rule out lichen planopilaris, which causes scarring hair loss).
- Skin biopsy: The pathologist looks for a band of lymphocytes along the upper skin layers, a sawtooth pattern of the rete ridges, and Civatte bodies (degenerated keratinocytes).
- Systemic screening tests: Liver function tests and hepatitis C (HCV) screening, because lichen planus and HCV infection are significantly linked in population studies.
Common Clinical Forms
The most common forms of lichen planus include:
- Cutaneous lichen planus: Flat purple bumps, usually on the inner wrists, the shins, and the lower back.
- Mucosal lichen planus: Most often in the mouth (a white lacy pattern or painful red erosions) and on the genitals.
- Lichen planopilaris (follicular lichen planus): Attacks the hair follicles and can lead to permanent scarring hair loss if not treated promptly.
- Nail lichen planus: Thins the nail plate, causes lengthwise ridges and splits, and can destroy the nail entirely (pterygium).
