The symptoms of anthrax disease vary depending on the route of exposure to anthrax.

Cutaneous anthrax

  • Initial symptoms include an itchy, reddish-brown lesion that typically appears on the exposed skin surface approximately 1 to 12 days after the spores enter a cut, abrasion, or open sore on the skin. The lesion quickly develops into a small, fluid-filled bump.
  • In the next stage of disease progression, the vesicle ruptures and leaves a painless ulcer that typically has a black area in the center and swollen surrounding tissue.
  • Other associated symptoms include swollen glands, fever, muscle aches, malaise, vomiting, and headache.
  • Without treatment, the fatality rate of cutaneous anthrax is estimated to be approximately 20%.

Gastrointestinal anthrax

  • The first symptoms usually appear within 1 to 7 days of ingesting contaminated food. These include nausea, fever, loss of appetite, severe stomach pain, vomiting of blood, and bloody diarrhea.
  • The fatality rate of gastrointestinal anthrax is estimated to be 25% to 60% without treatment.

Inhalational anthrax

  • Initial symptoms are generally non-specific and resemble that of the common cold — sore throat, mild fever, muscle aches, coughing, and chest discomfort lasting a few days.
  • The second stage develops abruptly, with symptoms such as sudden onset of fever, acute respiratory distress with abnormal accumulation of fluid in the pleural cavity, shock, and coma.
  • Meningitis is also commonly seen as the disease progresses.
  • Even with aggressive, intensive care, fatality rates of inhalational anthrax is approximately 45% to 90%.

Next: Transmission and Spread of Anthrax




BioThrax is a vaccine indicated for the active immunization for the prevention of disease caused by Bacillus anthracis in persons 18 through 65 years of age. BioThrax is approved for:

  1. Pre-exposure prophylaxis of disease in persons at high risk of exposure.
  2. Post-exposure prophylaxis of disease following suspected or confirmed Bacillus anthracis exposure, when administered in conjunction with recommended antibacterial drugs.

The efficacy of BioThrax for post-exposure prophylaxis is based solely on studies in animal models of inhalational anthrax.


Severe allergic reaction (e.g. anaphylaxis) after a previous dose of BioThrax or a component of the vaccine.

Adverse Reactions

The most common (≥10%) local (injection-site) adverse reactions observed in clinical studies were tenderness, pain, erythema, edema, and arm motion limitation. The most common (≥5%) systemic adverse reactions were muscle aches, headache, and fatigue. Acute allergic reactions, including anaphylaxis, have occurred with BioThrax.

Warnings and Precautions

Vaccination with BioThrax should be avoided by individuals with a history of anaphylactic or anaphylactic-like reaction following a previous dose of BioThrax or any component of the vaccine. If BioThrax is used during pregnancy, or if the patient becomes pregnant during the immunization series, the patient should be apprised of the potential hazard to the fetus. Pregnant women should not be vaccinated unless the potential benefits of vaccination have been determined to outweigh the potential risk to the fetus. It is not known whether BioThrax is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when BioThrax is administered to a nursing woman.

BioThrax should be administered with caution to persons with a possible history of latex sensitivity since the vial stopper contains dry natural rubber.