Can hydroxychloroquine (HCQ) cause oral ulcers?

Hydroxychloroquine and Oral Ulcers

Hydroxychloroquine does not typically cause oral ulcers; in fact, it is often used to treat certain conditions that present with oral ulcerations. While hydroxychloroquine can cause various side effects, oral ulcers are not among the commonly reported adverse reactions associated with this medication.

Side Effects of Hydroxychloroquine

• Hydroxychloroquine rarely causes serious adverse reactions when taken at prophylactic doses for malaria. Minor side effects may include gastrointestinal disturbance, headache, dizziness, blurred vision, and pruritus 1
• At higher doses, such as those used to treat rheumatoid arthritis, hydroxychloroquine may cause retinopathy, which requires periodic ophthalmologic examinations, especially for extended use (more than 6 years) 1
• Other potential side effects with prolonged use include headache, blurring of vision, diplopia, confusion, convulsions, lichenoid skin eruptions, bleaching of hair, and ECG abnormalities 1
• Prolonged therapy can cause toxic myopathy, cardiomyopathy, and peripheral neuropathy, which generally improve if the drug is promptly withdrawn 1

Hydroxychloroquine and Oral Conditions

• Rather than causing oral ulcers, hydroxychloroquine is actually used to treat several conditions that present with oral ulcerations:
  • Chronic ulcerative stomatitis (CUS) - a disease characterized by chronic ulceration of oral mucosa that responds well to hydroxychloroquine treatment 2
  • Oral lichen planus - hydroxychloroquine (200-400 mg daily) has shown excellent response in treating this condition, with pain relief and reduced erythema usually observed after 1-2 months of therapy 3, 4
  • Recalcitrant oral lichen planus - studies show significant reduction in pain scores and disease severity with hydroxychloroquine 200 mg twice daily in patients who don't respond to conventional therapy 4

Differential Diagnosis for Oral Ulcers in Patients Taking Hydroxychloroquine

If a patient on hydroxychloroquine presents with oral ulcers, consider:

• Underlying autoimmune conditions that hydroxychloroquine is treating (e.g., lupus, which commonly presents with oral ulcers) 5
• Other medications the patient may be taking concurrently
• Proguanil (another antimalarial) is known to cause mouth ulcers as a side effect, not hydroxychloroquine 1

Monitoring Recommendations

• Routine monitoring for hydroxychloroquine typically focuses on ocular toxicity rather than oral manifestations 1
• Ophthalmologic examinations are recommended every 6-12 months for patients on long-term therapy 1
• Monitor for drug interactions with D-penicillamine and cimetidine, which can lead to higher drug levels 1

Clinical Implications

• If oral ulcers develop in a patient taking hydroxychloroquine, consider:
  • Evaluating for disease flare of the underlying condition being treated
  • Reviewing other medications that might cause oral ulcers
  • Assessing for other causes of oral ulcers (infectious, traumatic, etc.)
• Hydroxychloroquine may actually be beneficial for treating certain types of oral ulcerations rather than causing them 2, 3, 6, 4

In summary, while hydroxychloroquine has several known side effects, oral ulcers are not typically attributed to this medication. In fact, hydroxychloroquine is often used therapeutically to treat conditions that manifest with oral ulcerations.