| Discussion: |
On initial interview, the patient denied any use of current medications. However with further questioning, patient recalled having had a recent course of doxycycline for the treatment of acne.
Drug-induced esophagitis is becoming increasingly more common. Tetracycline and its derivatives, especially Doxycycline, non-steroidal anti-inflammatory drugs, potassium chloride, iron tablets and quinidine are common offending agents. Doxycycline and tetracycline account for approximately 50% of reported cases of drug-induced esophagitis. Patients present with retrosternal chest pain, odynophagia, and dysphagia. Also in the history, patients report that pills were swallowed with little or no water, or immediately after going to bed. This predisposes the tablets to become lodged in the upper or mid-esophagus. Doxycycline capsules are relatively acidic and prolonged contact with the esophageal mucosa can produce edema, friability and superficial ulceration, triggering focal esophageal injury.
Double-contrast esophagraphy is the test of choice in diagnosing drug-induced esophagitis because it demonstrates small, superficial ulcers and other subtle mucosal abnormalities. Tetracycline and doxycycline produce small, shallow ulcers, whereas potassium chloride, quinidine and NSAIDs can cause larger, deeper ulcers that may lead to the formation of strictures. Since the ulcers produced by Tetracycline and Doxycycline are so small and superficial they never develop strictures. Fortunately, follow up studies show that within 7-10 days after withdrawal of the offending agent there is often complete healing of lesions. Drug-induced esophagitis can be prevented with good patient education. Setting guidelines on increased fluid intake with each pill and upright position for at least 10-15 minutes after ingestion are helpful to ensure clearing of medication from the esophagus.