What should you know about linear lichen planus pigmentosus?

Lichen planus pigmentosus is related to lichen planus but is recognised mainly by discolouration rather than raised, intensely itchy bumps. The linear form follows a narrow streak or a natural skin line and may be brown, grey-brown, or darker than nearby skin. Inflammation can stimulate or disturb pigment, and colour may remain after the active inflammation becomes quiet. Sun exposure, friction, and skin irritation can make contrast more obvious. A dark line has several possible explanations, so photographs or online comparisons cannot confirm this diagnosis.

Arrange a dermatology assessment, especially if the line is new, changing, or accompanied by bumps or itch. Use broad sun protection and avoid tanning, rubbing, harsh scrubs, and unprescribed lightening products. Keep a record of products, medicines, and preceding rashes. Depending on the findings, a clinician may discuss an anti-inflammatory topical medicine, including a topical corticosteroid for selected active areas. Oral corticosteroid treatment is reserved for particular situations and is not a routine solution for every pigment mark.

Seek review if the pigmentation spreads quickly, becomes raised, bleeds, ulcerates, or develops significant itch or pain. Prompt assessment is also sensible when colour change affects the eyelids, mouth, or another sensitive site, or when it follows a new medicine. A changing pigmented mark should be examined rather than treated only for appearance.

Ask whether the pattern is active inflammation or leftover pigment, whether a biopsy or medicine review would help, and which treatments are appropriate for your skin tone. Discuss realistic colour improvement, sun protection, and how recurrence would be monitored.