Mucosal Injury From Calcium Oxalate Crystals Resembling Anaphylaxis and Angioedema.

BACKGROUND: There are 215 families of plants that contain insoluble needle-shaped calcium oxalate crystals on the surface of their tissues. Upon mucosal contact, injury can cause extreme pain, soft-tissue swelling, salivation, dysphagia, and even aphonia. This presentation can resemble angioedema or anaphylaxis.

CASE REPORT: A 55-year-old Asian female presented to the emergency department complaining of oral pain, swelling, and numbness. Her family reported that she began to experience sharp pain of the tongue and lips immediately after eating "elephant root." Physical examination revealed a patient sitting in an upright position, leaning forward with pooling secretions. She had few lingual petechiae, a subtle diffuse erythema, and mild edema of the lower lip. Due to pain, she was unable to speak and swallow. Her vitals remained within normal limits. The patient was taking lisinopril for hypertension. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Injury by calcium oxalate crystals is a relatively common occurrence that will present to the emergency department. Although most exposures are benign, patients can develop critical illness, requiring emergent therapies and airway management. Due to the nature of presentation, exposure can easily be misdiagnosed as anaphylaxis or hereditary and drug-induced angioedema. Severe pain and the temporal relationship to plant ingestion distinguish insoluble calcium oxalate crystal exposure from these alternative causes of angioedema. There is minimal evidence-based data evaluating treatment of these injuries. Standard treatment regimen includes a local anesthetic, corticosteroids, opioids, and antihistaminergic agents. Given the relative low cost, ease of administration, and benign adverse effect profile, sodium bicarbonate rinse may have a role as an adjunct therapy, however, research is needed.