[The development of a toxic megacolon due to Amanita phalloides poisoning. A rare complication]

Pneumatosis intestinalis and hepatic portal venous gas in patient with Amanita exitialis poisoning: A case report from Shenzhen, China

A 57-year-old male admitted as an emergency for mushroom poisoning with hypovolemic shock, acute renal injury (Cr 213 μmol/L) and metabolic acidosis (pH 7.1). Twenty-six hours ago, he consumed 4 caps of wild mushrooms and presented with acute gastroenteritis, generalized malaise and lower limbs jerk. On ICU admission, he developed ventricular defibrillation and was resuscitated with intubation and ventilation. In addition to plasma exchange and hemoperfusion therapy, the patient was managed with massive fluid and potassium replacement, vasopressors, activated charcoal, silymarin, penicillin G and piperacillin tazobactam. On ICU Day 2, the patient's general condition improved with vasopressor ceased, renal function normalized except large amount of diarrhea. On ICU Day 3, the patient deteriorated again with worsening abdominal distension leading to intra-abdominal hypertension (IAH). Toxic liver injury by mushroom became significant. Repeated acute renal injury, deranged clotting and compromised hemodynamics were also noted which indicated acute abdominal compartment syndrome. Emergent computed tomography (CT) of abdomen revealed Pneumatosis intestinalis (PI) in the small intestines and hepatic portal venous gas (HPVG) in the left liver lobe. Water assisted colonoscopy decompression was performed emergently for IAH relief. Thereafter, the patient improved rapidly with organ dysfunction recovered next day. Acute liver failure gradually subsided. On ICU Day 8, the patient was discharged to general ward. The mushroom was later morphologically identified as Amanita exitialis (A. exitialis) by at least two specialists from Chinese Centre for Disease Control and Prevention (CDC). A. exitialis is a lethal mushroom that mainly affect liver and gastrointestinal (GI) tract. The current case and literature review suggest that the severity of GI injury caused by lethal A. exitialis may be underestimated.

An outbreak of Amanita exitialis poisoning

BACKGROUND

The mushroom Amanita exitialis is reported to cause acute liver injury. It is found in Southern China, and has been previously associated with a high incidence of mortality.

METHODS

We described a series of 10 patients with Amanita exitialis poisoning admitted to The Second Affiliated Hospital of the Chinese University of Hong Kong (Shenzhen) in April 2022. Patient demographics, clinical features, laboratory results, therapeutic interventions, and outcome data were collected.

RESULTS

Among the 10 patients, 9 survived, while 1 died. Gastrointestinal symptoms were the first to appear (average latency period, 11 ± 4.2 h). Diarrhea was the most common clinical symptom (average duration, 4.4 days). Abdominal distention was an important sign, especially in severely-ill patients. Thrombocytopenia occurred on day 2 after mushroom ingestion and persisted for 3-4 days. Alanine aminotransferase and total bilirubin peaked on days 2-3.

CONCLUSION

Amanita exitialis poisoning is characterized by gastrointestinal symptoms and liver injury. In the patient who died, acute hepatic failure led to hepatic encephalopathy and cerebral edema. Abdominal distension accompanied by thrombocytopenia was common in critically ill patients in this outbreak.

Ulcerating Ileocolitis in Severe Amatoxin Poisoning

Amatoxin poisoning is still associated with a great potential for complications and a high mortality. While the occurrence of acute gastroenteritis within the first 24 hours after amatoxin ingestion is well described, only very few descriptions of late gastrointestinal complications of amatoxin poisoning exist worldwide. We present the case of a 57-year-old female patient with severe amatoxin poisoning causing fulminant but reversible hepatic failure that on day 8 after mushroom ingestion developed severe abdominal pain and watery diarrhea. Ulcerating ileocolitis was identified by computed tomography identifying a thickening of the bowel wall of the entire ileum and biopsies taken from the ileum and large bowel revealing distinct ileitis and proximally accentuated colitis. The absence of discernible alternative etiologies such as infectious agents makes a causal relationship between the ulcerating ileocolitis and the amatoxin poisoning likely. Diarrhea and varying abdominal pain persisted over several weeks and clinical follow-up after six months showed a completely symptom-free patient. The case presented highlights the importance to consider the possibility of rare complications of Amanita intoxication in order to be able to respond to them early and adequately.