Lake Erie College of Osteopathic Medicine Erie, PA
Martin Ankamah, MBA1, Robert S. Aaron, MD2 1Lake Erie College of Osteopathic Medicine, Erie, PA; 2Allied Digestive Health (Middlesex Monmouth Gastroenterology), Freehold, NJ Introduction: Rhizopus diarrhea, or gastrointestinal mucormycosis, is a rare and often fatal disease caused by fungi, usually the Rhizopus species, belonging to the order Mucorales. Patients may experience diarrhea, abdominal pain, and GI bleeding. However, due to the non-specific nature of these symptoms, this diagnosis is challenging. Typical risk factors include immunosuppression, uncontrolled diabetes, and severe COVID-19. It is not contagious and spreads via inhalation or ingestion of spores from the environment. Amphotericin B is a common first-line treatment, but surgical debridement of infected tissue in the stomach, colon, or ileum may be required. The objective of this clinical vignette is to add to the current knowledge of Rhizopus diarrhea.
Case Description/
Methods: A 69-year-old woman with a past medical history significant for rheumatoid arthritis (on hydroxychloroquine), Sjogren's disease, and fibromyalgia was evaluated in the emergency department at a community hospital for four weeks of persistent, nonbloody diarrhea. Laboratory workup at that time demonstrated a normal WBC count, hemoglobin of 11.5 g/dL, hematocrit of 36.5%, and MCV of 100.8 fL. A comprehensive metabolic panel and serum procalcitonin level were normal. Stool cultures were sent and ultimately came back positive for Rhizopus. Stool for C. diff and WBCs was negative. A CT scan of the abdomen and pelvis with contrast was normal. The patient was discharged home and then contacted by the emergency department to return to the hospital after her stool cultures resulted. Discussion: The hyphae of Rhizopus invade blood vessel walls causing endothelial damage that lead to thrombosis and ischemia of GI tissue. Outbreaks are rare but have occurred following natural disasters and in hospital settings. With a mortality rate as high as 85%, early detection and antifungal treatment of Rhizopus diarrhea is critical to increasing the likelihood of a favorable outcome for patients. In this case, imaging was not consistent with the presence of severe colitis, which suggests that the patient’s diagnosis occurred early enough to increase the probability of a favorable prognosis. As physicians continue to maintain a high degree of clinical suspicion, especially with immunocompromised patients, one additional consideration is for the inclusion of Rhizopus diarrhea as a differential diagnosis for patients with at least one autoimmune disorder and non-specific GI complaints.
Figure: A. Rhizopus fungi under microscope B. axial view CT abdomen C. coronal view CT abdomen
Disclosures: Martin Ankamah indicated no relevant financial relationships. Robert Aaron indicated no relevant financial relationships.
Martin Ankamah, MBA1, Robert S. Aaron, MD2. P4659 - Rhizopus Diarrhea: A Rare Fungus Among Us Not to Be Missed!, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.
