Doxycycline Induced Gastrointestinal Injury

Summary Doxycycline induced gastric injury is a rarely recognized side effect of a common medication. Only two cases have previously described the distinctive capillary degeneration identified in gastric mucosa. We expanded on this by describing additional involved sites, endoscopic findings and patient characteristics. Design Gastrointestinal biopsy materials for cases indexed with the word “doxycycline” were retrieved and the histology reviewed. The medical record was used to obtain clinical details. Three cases with biopsy materials were identified from the search and doxycycline ingestion was confirmed. All patients' gastric biopsies had small vessel injury with fibrinoid material around the vessel, and one patient had similar changes in the duodenum. Endoscopic findings included fundic and pyloric erosions and ulcers. One patient had a normal endoscopy on follow-up after drug cessation. Confirmation and increased understanding of this drug-specific injury pattern is important for patient management as cessation appears to result in symptom improvement and healing.