There are four forms of disease caused by anthrax: cutaneous (skin) anthrax, inhalation anthrax, gastrointestinal (bowel) anthrax, and the newly designated injection anthrax.

Cutaneous anthrax

    The cutaneous (skin) form of anthrax (80% of all anthrax infections) starts as a red-brown raised spot that enlarges with considerable redness around it, blistering, and hardening. The center of the spot then shows an ulcer crater with blood-tinged drainage and the formation of a black crust called an eschar. There are swollen glands (lymph nodes) in the area. Symptoms include muscle aches and pain, headache, fever, nausea, and vomiting. The illness usually resolves in about six weeks, but deaths may occur if patients do not receive appropriate antibiotics.

Injection anthrax

    This new form of anthrax has been identified in heroin-injecting drug users in northern Europe and has not yet been reported in the United States. Symptoms may take days to months before they appear. The signs and symptoms of injection anthrax can include small blisters or bumps that may itch at the injection site, fever and chills, swelling around the sores, and deep abscesses may develop under the skin or muscle. Painless skin sores with black centers (dark scabs) may appear after the blisters or bumps develop.

Inhalation anthrax

    The first symptoms are subtle, gradual and flu-like (influenza) with a sore throat and headaches. In a few days, however, the illness worsens and there may be severe respiratory distress with shortness of breath and pain in the chest and/or muscles. Some patients may begin coughing up blood. Shock, coma, and death follow. Inhalation anthrax does not cause a true pneumonia. In fact, the spores get picked in the lungs up by scavenger cells called macrophages. Most of the spores are killed. Unfortunately, some survive and are transported to glands in the chest called lymph nodes. Lymph nodes may swell. In the lymph nodes, the spores that survive multiply, produce deadly toxins, and spread throughout the body. Severe hemorrhage and tissue death (necrosis) occurs in these lymph nodes in the chest. From there, the disease spreads to the adjacent lungs and the rest of the body. Inhalation anthrax is a very serious disease, and unfortunately, most affected individuals will die even if they get appropriate antibiotics. Why is this so? The antibiotics are effective in killing the bacteria, but they do not destroy the deadly toxins that have already been released by the anthrax bacteria.

Gastrointestinal anthrax

    Now rare, anthrax of the bowels (gastrointestinal anthrax) is the result of eating undercooked, contaminated meat. The symptoms of this form of anthrax include nausea, loss of appetite, bloody diarrhea and fever followed by abdominal pain. The bacteria invade through the bowel wall. Then the infection spreads throughout the body through the bloodstream (septicemia) with deadly toxicity.