Ricin Exposure Clinical Presentation

Updated: May 27, 2021
  • Author: Ferdinando L Mirarchi, DO, FAAEM, FACEP; Chief Editor: Zygmunt F Dembek, PhD, MS, MPH, LHD  more...
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In the case of an isolated attack involving ricin (eg, an assassination attempt), no historical markers may be present. If a number of patients are affected simultaneously, by either ingestion or inhalation, the subsequent cluster of patients presenting with similar symptoms over a brief time may alert an astute clinician to the possibility of an intentional act. This is especially true in the case of an inhalation incident (ingestion initially may mimic food poisoning).

The usual significant factors associated with toxic environmental exposures should be addressed, including the following:

  • Identification of the toxic substance

  • Time and duration of exposure

  • Symptoms

  • Treatment thus far

  • Associated injuries

  • Preexisting conditions

In cases of ingestion, an effort should be made to obtain a sample of the exact bean ingested, if possible; this greatly facilitates the identification process. It is important to be aware that beans are often known by various names, both common and scientific. In the United States, the castor oil plant (see the first image below) grows wild in the southwest, mainly along streams and riverbeds; gardeners in colder areas grow the plant as an ornamental annual. Castor beans (see the second image below) are oblong and brown in color with speckled dark brown spot. Castor beans are easily purchased in many horticulture and plant shops and over the Internet.

Castor bush. Castor bush.
Castor beans. Castor beans.

Although a patient is unlikely to be aware of contamination of ingested foods or beverages, an effort should be made to determine approximately when exposure occurred and to what degree (including how many beans were chewed and whether any were swallowed).

After ingestion of castor beans, symptoms develop within 8-24 hours (see the image below). The clinical picture can include gastrointestinal (GI) symptoms that can progress to hypotension, liver and renal failure, and death. After inhalation of ricin, illness can develop within 8 hours. Symptoms include cough, dyspnea, arthralgias, fever, respiratory distress, and death. After injection of ricin, symptoms develop within 6 hours, including weakness and myalgias with progression to fever, hypotension, multiple organ failure, and death. [15]

Chemical Terrorism Agents and Syndromes. Signs and symptoms. Chart courtesy of North Carolina Statewide Program for Infection Control and Epidemiology (SPICE), copyright University of North Carolina at Chapel Hill, www.unc.edu/depts/spice/chemical.html. (PDF)

It is important to determine whether the patient has received any treatment before presentation. Inquiries should be made regarding any other potential exposures or injuries. A victim of an attack may relate the pain of an antecedent injection, but this may be overlooked during the history. Inquiries should also be made regarding past medical history, medications, and allergies.


Physical Examination

With any exposure to ricin, a complete physical examination is essential. Airway patency should be assessed. Oral or upper airway swelling severe enough to cause airway compromise is extremely uncommon, and breathing is usually unaffected. Circulation may be affected as shock develops, secondary to severe gastroenteritis. Severe cutaneous hypersensitivity or systemic allergic reactions may occur. An urticarial, immunoglobulin E–mediated allergic reaction may occur, with tongue or facial swelling, bronchospasm, and acute upper airway obstruction.

In parenteral exposure, the site should be inspected for induration, erythema, and the possibility of a retained foreign body. These physical findings may be present before or simultaneously with systemic manifestations.

In aerosol exposure, the presentation is that of a rapidly progressive acute lung injury. Physical findings are consistent with the stage of progression, from normal physical examination results through hypoxia, cyanosis, labored breathing, tachypnea, tachycardia, and progressive respiratory failure.

In GI exposure, physical examination should yield findings consistent with gastroenteritis and volume depletion. If the dose was sufficient and the disease had progressed, frank hematemesis, bloody diarrhea, or melena may be present.