Alternative Names: Anthrax - skin

Causes, incidence, and risk factors:

Anthrax is caused by the bacteria Bacillus anthracis. While anthrax commonly affects hoofed animals such as sheep and goats, humans may get sick from anthrax, too. The most common type of anthrax infection is�cutaneous anthrax, an infection of the skin. Cutaneous infections account for 95% of all anthrax cases worldwide.

Cutaneous anthrax�occurs after the bacteria touches a cut or scrape on the skin.�After about�two weeks, an itchy sore develops, similar to an insect bite. This�sore may blister and form a black ulcer, which is usually painless. It is usually surrounded by significant swelling.� A scar often develops,�and then dries and falls off within two weeks. Some patients have�painful lymph nodes.

In�some cases, the infection can spread through the bloodstream and become fatal. However, death is extremely rare in the majority of individuals who receive�prompt, appropriate treatment.

Historically, the main risk factor for acquiring cutaneous anthrax is contact with animal hides or hair, bone products, and wool, as well as contact with infected animals. Therefore, those most at risk for anthrax include farm workers, veterinarians, and tannery and wool workers.

Anthrax is a potential agent for use as a biological weapon or for bio-terrorism. In 2001, bioterrorist activities involving the U.S. Postal Service infected�22 people with anthrax; 7 survivors had confirmed cutaneous anthrax disease.While at least 17 nations are believed to have a biological weapons program, it is unknown how many nations or groups are working with anthrax. Most bio-terrorism experts have concluded that it is technologically difficult to use anthrax effectively as a weapon on a large scale.

Symptoms:

• Blister or ulcer that later forms a black scab; often with extensive surrounding swelling
• A few patients may also experience fever, headache, and malaise
• Swollen, painful lymph nodes

Signs and tests:

• If cutaneous anthrax is suspected, a culture of the skin lesions should be done to identify the bacteria that causes anthrax.

Treatment:

Cutaneous anthrax is treated with oral antibiotics (pills). Several antibiotics are effective, including penicillin, doxycycline, and ciprofloxacin (Cipro).� Cipro has been the antibiotic of choice during a suspected anthrax outbreak.

Because anthrax spores may take up to 60 days to germinate, the length of treatment is usually 60 days.

Support Groups:

Expectations (prognosis):

The prognosis of treated cutaneous anthrax is excellent. Death is extremely rare when antibiotics are promptly given.

Complications:

In about 20% of untreated cases of cutaneous anthrax, the organism may spread into the bloodstream, leading to shock and death.

Calling your health care provider:

Call your health care provider if you know you have been exposed to anthrax, or if�you develop a skin lesion as described above.

Prevention:

There are two primary modes of prevention of anthrax.

For individuals who have been truly exposed to anthrax (but have no signs and symptoms of the disease), preventive antibiotics may be offered, such as ciprofloxacin, penicillin, or doxycycline, depending on the particular strain of anthrax.

An anthrax�vaccine is available to selected military personnel, but not to the general public. It is given in a 6-dose series.

There is no known transmission of cutaneous anthrax from person to person. Household contacts of individuals with cutaneous anthrax do not need antibiotics unless they have also been exposed to the same source of anthrax.

References:

Reissman DB, Whitney EA, Taylor TH Jr, et al. One-Year Health Assessment of Adult Survivors of Bacillus anthracis Infection.��JAMA. 2004;291:1994-1998.

Inglesby TV, O'Toole T, Henderson DA, et al. Anthrax as a Biological Weapon, 2002. JAMA.�2002;287:2236-2252.