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Purple, flat, itchy bumps, or white lacy lines in the mouth

Also called: Lichen planus

Purple, flat, itchy bumps on the skin, or white lacy lines in the mouth, are signs of lichen planus. It's not contagious and often fades over time.

Common causesLichen planus
Usually serious?Usually not
Get checked ifMouth sores, or genital involvement
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

It may be linked to hepatitis C.

Mouth forms need follow-up.

When to get medical care

Call 911Not an emergency.
Get care todayNot usually urgent.
See a doctor soonItchy purple bumps or mouth lines.

Causes

Cause is unknown; some medicines trigger it.

OwieClear has pages on 1 condition that can cause purple, flat, itchy bumps, or white lacy lines in the mouth. Each shows how soon to get care.

Common causes

  • Lichen planusSee a doctor if it doesn't get better

    An inflammatory condition that causes itchy, flat, purple bumps on the skin, often on the wrists and ankles, or white lacy lines inside the cheeks.

What you can do at home

  • Avoid scratching.
  • Avoid spicy foods if mouth is sore.

Medicines

Steroid creams or rinses.

At the doctor

Diagnosed by exam.

Questions you may be asked

  • Medicines

The exam

A skin and mouth exam.

Tests

  • Biopsy
  • Hepatitis C test

Prevention

Follow up.

  • Regular dental checks

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

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Sources

Last updated 2026-11-13.