Cutaneous infection accounts for about 95% of all human cases, followed by inhalation and gastrointestinal anthrax, which are very rare. Cutaneous infections start when the organism enters the body via open skin wounds or abrasions, resulting in skin lesions. The first symptom is a pus-filled elevation on the skin, which then turns into an open ulcer. The most severe cases may invade the bloodstream, resulting in death. The cutaneous form is known as wool sorter's disease because historically, many cases were contracted by people who accidentally inhaled anthrax spores while handling contaminated animal hides or fleeces.
Symptoms associated with gastrointestinal anthrax, contracted through the ingestion of contaminated food products, include pharyngeal lesions with a sore throat, swelling in the neck; or intestinal infection, resulting in nausea, fever, severe abdominal pain, bloody diarrhea, and hemorrhages. There is a 25 to 50% fatality rate.
Inhalation anthrax is the most severe form and results from inhalation of spores. The spores are small enough to enter the alveoli, germinate, and produce the exotoxins, resulting in infection and a 90% fatality rate if not treated. Symptoms first resemble those associated with pneumonia: fever, chills, cough, headache, and malaise, followed by more serious symptoms such as hemorrhages and septic shock.
