Identifying the Symptoms of Ricin Exposure

Swine Flu (H1N1) Vaccine Slideshow Swine Flu (H1N1) FAQ Slideshow Strep or Sore Throat Slideshow

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

Concern about the use of the toxin ricin as a terrorist weapon have surfaced following media reports of isolated findings and poisonings related to this substance. Ricin is a naturally occurring toxin that is found in castor beans. Ricin poisoning may occur from chewing and swallowing castor beans, and the toxic substance can also be obtained the waste material that remains after processing castor beans to produce castor oil.

Ricin can take many forms: It can be a powder, a mist, a pill or pellet, and can be dissolved in water and other liquids. This means that a person can contract ricin poisoning via inhalation or ingestion; the initial symptoms of ricin poisoning depend upon both the degree and route of exposure. Accidental exposure to ricin unrelated to the ingestion of castor beans would be extremely unlikely to occur.

If ricin is inhaled, symptoms typically begin within eight hours of exposure and include difficulty breathing, fever, cough, nausea, sweating, and a feeling of tightness in the chest. The skin may turn blue due to the decreased oxygenation of blood resulting from fluid buildup (edema) in the lungs. Low blood pressure and respiratory failure may ultimately occur.

Ricin exposure by ingestion (swallowing) typically results in symptoms in less than six hours following exposure. Symptoms include vomiting and diarrhea that may contain blood, possibly resulting in dehydration severe enough to cause low blood pressure, and blood in the urine. Ricin ingestion can also cause disturbances in the central nervous system, potentially leading to hallucinations or seizures. Within several days, multi-organ failure can result.

Depending on the degree of exposure, death can result within 36 to 72 hours from both inhalation and ingestion of ricin. Skin contact with ricin powder is not likely to cause serious damage, since ricin is not generally well absorbed through normal skin. However, contact with ricin powder or products may cause pain and redness of the skin and the eyes. Ricin poisoning is not contagious and cannot be spread from one affected person to another by casual contact.

There is no antidote for ricin poisoning, and medical treatment consists of supportive measures (such as breathing support, intravenous fluids, and medications to control blood pressure and seizures) to try to counteract or reduce the effects of the toxin on the body.

Reference: U.S. Centers for Disease Control and Prevention (CDC), "Facts About Ricin," Mar. 5, 2008.