What should you know about lichen planus pigmentosus LPP?

The word pigmentosus refers to altered skin colour. Patches may appear on the face, neck, arms, or other areas, and their shade can vary with natural skin tone. Some people notice mild itch or irritation before colour becomes more obvious; others have little sensation. It is different from the raised, often itchy bumps associated with classic lichen planus, although both belong to the same condition family. See the overview of [Lichen Planus](/conditions/lichen-planus/) and related information about [Itchy Skin](/symptoms/itchy-skin/).

Arrange a dermatology review if new patches are spreading, changing, or difficult to distinguish from another pigment condition. The clinician may examine the distribution, surface, and colour, and may consider a skin sample when the diagnosis is uncertain. Use gentle, fragrance-free products, avoid rubbing affected areas, and protect exposed skin from sunlight because light can make colour contrast more noticeable. Treatment is individualised; options can include [Topical Corticosteroids](/treatments/medical-dermatology/topical-corticosteroids/) when active inflammation is present.

Book an assessment promptly for rapidly expanding patches, significant redness, pain, swelling, blistering, or bleeding. Seek urgent help for facial swelling with breathing difficulty, widespread blistering, or a severe reaction after applying a product. A new dark mark that is irregular, persistently changing, or unlike the surrounding patches also deserves direct examination rather than self-treatment.

Could this be lichen planus pigmentosus or another cause of pigmentation? Is inflammation still active? Would a biopsy clarify the diagnosis? Which products should I stop, and how should treatment be monitored?