Papulosquamous (Psoriasis, Lichen)
Lichen Planus
WHAT IS IT
An itchy, immune-driven skin & mucosa rash
HOW COMMON
Fairly common, often in middle age
CONTAGIOUS?
No — you cannot catch it or spread it
CURABLE?
Often self-limited; symptoms are manageable
What Is It?
Lichen planus is an itchy rash caused by the immune system mistakenly attacking the skin. It shows up as flat-topped, purple, shiny bumps, often on the wrists, ankles, and lower back. It can also affect the mouth, genitals, nails, and scalp. Many cases clear over months to a couple of years.
Signs & Symptoms
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Flat-topped, shiny, purple or reddish bumps
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Itching, sometimes intense
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Fine white lines over the bumps (Wickham's striae)
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Lacy white patches in the mouth, or sores
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Nail ridging/thinning or scalp patches in some cases
Why Does It Happen?
Lichen planus happens when immune cells attack the skin or lining of the mouth. The exact trigger is often unknown, but it can be linked to certain medications, viral infections (such as hepatitis C), or contact allergies. It is NOT an infection and NOT contagious.
Treatment Options
Treatment calms the immune reaction and relieves itch. Many skin cases resolve on their own, but mouth, genital, scalp, and nail involvement often need more attention.
TOPICAL STEROIDS
First-line to calm inflammation and itch in most skin cases.
CALCINEURIN INHIBITORS
Steroid-free option, useful in the mouth and genital areas.
ORAL / LIGHT THERAPY
Steroids, other pills, or phototherapy for widespread disease.
REVIEW MEDICATIONS
Checking for a drug trigger, and screening for hepatitis C when relevant.
Tips for Managing It at Home
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Avoid scratching, which can spread bumps to injured skin
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Use gentle, fragrance-free skin and mouth care products
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For mouth involvement, avoid spicy, acidic, or crunchy foods during flares
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Keep dental and skin follow-up, as some forms need monitoring
When to Call Your Provider
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Painful mouth or genital sores that limit eating or daily life
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Rapidly spreading rash or severe itching
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Nail changes or scalp patches with hair loss
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No improvement, or persistent sores that don't heal
Sources & further reading
The information in this handout is based on general dermatology guidance from the reputable organizations below. These links are provided for patients who wish to read more from trusted sources.
American Academy of Dermatology (AAD). Lichen Planus: Overview. https://www.aad.org/public/diseases/a-z/lichen-planus-overview
DermNet. Lichen Planus. https://dermnetnz.org/topics/lichen-planus
MSD/Merck Manual. Lichen Planus. https://www.msdmanuals.com/professional/dermatologic-disorders/psoriasis-and-scaling-diseases/lichen-planus
This handout is for general education and does not replace advice from your own provider. Always follow your provider’s specific instructions.
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