KYT Dental Services
Hydroxychloroquine · Oral lichen planus

Hydroxychloroquine and oral lichen planus reactions

Quick answer

Hydroxychloroquine (Plaquenil) is a recognized cause of oral lichenoid reactions, which look like and behave like oral lichen planus: white lacy patches, redness, or shallow ulcers, usually on the inner cheeks or tongue. The reactions can be painful or asymptomatic. They are not contagious and not cancer, but they can mimic other serious conditions and should be evaluated. Most cases improve when the medication is stopped or substituted, but stopping is not always an option for the underlying autoimmune disease.

The mechanism
Why hydroxychloroquine causes lichenoid reactions

Hydroxychloroquine modulates the immune system, which is why it is used for lupus, rheumatoid arthritis, and other autoimmune conditions. In a small subset of patients, the medication appears to trigger an inflammatory reaction in the oral lining that closely resembles spontaneous oral lichen planus. The cells of the immune system (particularly T-cells) attack the basal layer of the mouth lining, producing the characteristic white lacy striations and sometimes red or ulcerated areas.

The lesions tend to appear on the inner cheeks, the sides of the tongue, the gums, or the palate. They can range from asymptomatic white patches that a dentist notices during a routine exam to painful ulcerative areas that interfere with eating. The pattern often suggests medication-related rather than spontaneous lichen planus, particularly when it appears within months of starting hydroxychloroquine and resolves on stopping.

Hydroxychloroquine can also rarely cause blue-gray pigmentation of the palate and gums with long-term use, a separate but related effect. This pigmentation is largely cosmetic and is not a sign of disease, but it should be documented so it is not mistaken for melanoma or other concerning pigmented lesions.

Practical steps
What to do about lichenoid reactions on Plaquenil
  • Get any new white patches, redness, or ulcers evaluated by your dentist. The diagnosis usually involves visual examination and sometimes a small biopsy to rule out other conditions.
  • Do not stop Plaquenil on your own. The decision to continue, reduce, or switch is made with your rheumatologist or prescribing physician.
  • If lesions are painful, use a soft-bristle toothbrush and avoid alcohol-containing mouthwash.
  • Avoid spicy, acidic, or sharp foods during active lesions.
  • Topical corticosteroid rinses or ointments often help symptoms. Your dentist may prescribe these.
  • Tell your prescribing physician. If the lesions are severe or persistent, they may switch you to a different DMARD.
Red flags
When to call your dentist
  • White lacy patches in the mouth that have been present more than two weeks.
  • Painful red areas or shallow ulcers that recur or do not heal.
  • New blue-gray pigmentation on the palate or gums.
  • Lesions that change in appearance over time, especially becoming firmer or more raised.
  • Difficulty eating or speaking because of mouth discomfort.
Common questions
What patients ask about Hydroxychloroquine (Plaquenil) and oral lichen planus reactions.
Are oral lichenoid reactions from Plaquenil cancer?
No. They are an immune-mediated reaction, not a cancerous lesion. However, spontaneous oral lichen planus (the version that occurs without medication) carries a small long-term risk of malignant transformation, which is why any oral lichenoid lesion warrants evaluation and sometimes long-term monitoring.
Do the lesions go away if I stop Plaquenil?
Usually yes, gradually, over weeks to months. The hallmark of a medication-related lichenoid reaction is that it resolves on stopping the drug, which distinguishes it from spontaneous lichen planus that persists regardless. Do not stop Plaquenil without medical guidance.
What is the difference between oral lichen planus and a Plaquenil lichenoid reaction?
Clinically and microscopically, they look almost identical. The distinction is the relationship to the medication: if the lesions started after Plaquenil was begun and resolve when it is stopped, they are likely drug-related. If the lesions persist on stopping or were present before, they are likely spontaneous oral lichen planus.
Can my dentist treat the lesions while I stay on Plaquenil?
Often yes. Topical corticosteroids (triamcinolone gel, dexamethasone rinse) can manage symptoms while you continue the medication. For mild asymptomatic lesions, observation alone may be appropriate. Your dentist and prescriber coordinate the plan based on severity and the underlying condition.
What if the pigmentation on my palate is from Plaquenil?
Plaquenil-related pigmentation is usually blue-gray, symmetric, and develops with long-term use. It is largely cosmetic. Once documented in the chart, it is generally left alone. The bigger concern is making sure it is not confused with melanoma or other concerning pigmented lesions, which is why a dental exam (sometimes including a small biopsy) is important when new pigmentation appears.
Talk to a dentist about your case
Bring your medication list to your visit.

General guidance is a starting point. Your specific dental plan depends on your medical history, your other medications, and what your mouth looks like in person. Schedule a consultation and we’ll walk through it.

Schedule a consultationCall (833) 598-3368

Reviewed by Dr. Isaac Sun, DDS.

This page is general information, not medical advice. Do not start, stop, or change any medication based on what you read here. Talk to your prescribing physician and your dentist about your specific situation.