Orellanine Mushroom Toxicity Clinical Presentation

Updated: Feb 13, 2019
  • Author: Reed Brozen, MD; Chief Editor: Sage W Wiener, MD  more...
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History of exposure is of utmost importance; without it, diagnosing mushroom or orellanine poisoning is unlikely. History of mushroom ingestion may be remote, particularly with orellanine, since early gastrointestinal symptoms may not be severe enough for patients to seek medical attention. Patients with symptoms of renal failure may not present until 1-3 weeks after exposure. The emergency physician should routinely inquire about mushroom ingestion whenever a patient presents with gastroenteritis. A shorter latent period before onset of illness suggests more severe toxicity and greater risk of more severe renal failure than delayed onset of illness.

Improvement in renal injury may occur within several weeks to months; however, renal injury may last months to years and patients may require long-term hemodialysis or kidney transplantation.

Important details of ingestion include the following:

  • Time of ingestion and, most importantly, time from ingestion to onset of symptoms (onset typically delayed)
  • Amount ingested
  • Whether co-ingestion of other types of mushrooms occurred
  • Whether other people ingested the same mushrooms and, if so, their reactions or symptoms
  • Where the mushrooms were picked

Gastrointestinal signs and symptoms are usually mild and observed 24-48 hours postingestion. They may include the following:

  • Nausea and vomiting
  • Abdominal pain
  • Diarrhea or constipation

Renal manifestations may include the following:

  • Flank pain
  • Intense thirst (sometimes described as burning)
  • Polyuria or oliguria
  • Anuria (rare)
  • Acute kidney injury may occur any time from 36 hours to 2 weeks postingestion.

Systemic manifestations may include the following:

  • Anorexia
  • Chills
  • Myalgias
  • Dysgeusia
  • Rash

Neurologic manifestations may include the following:

  • Somnolence
  • Lassitude
  • Headache
  • Paresthesias
  • Tinnitus
  • Seizures (rare)

Physical Examination

Patients with orellanine induced renal failure may have a paucity of findings on physical examination, as follows:

  • Volume status: With anorexia and polyuria, volume depletion may be present. With anuric renal failure, volume overload is possible.

  • Neurologic: With modest degrees of renal dysfunction, mental status may be relatively preserved. With more advanced renal failure, depressed mentation, confusion, or coma may occur. Myoclonus and asterixis suggest uremia in this setting.

  • Gastrointestinal: By time of presentation, abdominal symptoms may have resolved.

  • Renal: Flank tenderness may be present.

  • Other findings: Signs of uremia (eg, pericarditis, pleuritis, volume overload) may be present.