Differential Diagnosis for Multiple Ulcers in Mouth After Staring Ezetrol

• Single Most Likely Diagnosis
  • Oral lichen planus or a lichenoid reaction: This is a common condition that can be triggered by medications, including ezetrol (ezetimibe), and can cause multiple ulcers in the mouth. The fact that stopping ezetrol did not lead to improvement and the lack of response to antihistamines does not rule out this diagnosis, as these reactions can sometimes persist after the offending drug is discontinued.
• Other Likely Diagnoses
  • Aphthous ulcers: These are recurrent, painful ulcers in the mouth that can be triggered by various factors, including stress, trauma, and certain medications. The presentation of multiple ulcers could fit this diagnosis, although the temporal relationship with ezetrol initiation is suggestive of a drug-induced cause.
  • Drug-induced stomatitis: Although ezetrol has been stopped, other medications or substances could be causing the ulcers. A thorough review of the patient's medication list and potential exposures is necessary.
• Do Not Miss Diagnoses
  • Cancer (e.g., oral squamous cell carcinoma): Although the patient does not have weight loss, which is a common symptom of cancer, it is crucial not to miss a diagnosis of oral cancer, especially in non-smokers, as it can present with ulcers. Biopsy of the ulcers may be necessary to rule out malignancy.
  • Autoimmune disorders (e.g., pemphigus, pemphigoid): These conditions can cause oral ulcers and are important to diagnose early due to their potential for significant morbidity and the need for specific treatments.
• Rare Diagnoses
  • Behçet's disease: A rare condition characterized by recurrent oral ulcers, genital ulcers, and ocular inflammation. It is less likely but should be considered if other symptoms are present.
  • Erythema multiforme or Stevens-Johnson syndrome: Although these conditions are rare and typically present with more systemic symptoms and skin lesions, they can cause oral ulcers and are important to recognize due to their potential severity.