Cutaneous anthrax is an infection of the skin due to direct contact with the bacteria Bacillus anthracis.

Anthrax - skin

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 in people is cutaneous anthrax, an infection of the skin.

The main risk factor for getting 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.

Cutaneous anthrax occurs after the bacteria touch a cut or scrape on the skin.

Anthrax is a potential agent for use as a biological weapon or for bioterrorism. In 2001, bioterrorist activities involving the United States Postal Service infected 22 people with anthrax. Seven survivors had confirmed cases of cutaneous anthrax. Most bioterrorism experts have concluded that it is technologically difficult to use anthrax effectively as a weapon on a large scale.

Between 1 and 12 days after exposure, an itchy sore develops, similar to an insect bite. This sore may blister and form a black ulcer (sore), which is usually painless. It is usually surrounded by significant swelling. A scab often develops, and then dries and falls off within 2 weeks, although complete healing can take longer.

Some patients also have painful lymph nodes, fever, headache, and a general ill-feeling (malaise).

A culture of the skin lesions should be done to identify the bacteria that cause anthrax.

Cutaneous anthrax is treated with antibiotics, most often doxycycline or ciprofloxacin. Ciprofloxacin has been the antibiotic of choice during a suspected anthrax outbreak.

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

The outlook is excellent when anthrax is treated. Death is extremely rare when antibiotics are promptly given.

In some cases, the infection can spread through the bloodstream, leading to shockand death.

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

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

Cutaneous anthrax is not known to spread 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.

An anthrax vaccine is available to selected military personnel, but not to the general public.

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

Lucey DR. Anthrax. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 317.

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.

Is Anthrax contagious? I guess it depends on how you interpret the information.

Anthrax is not contagious; it cannot be transmitted from person to person.

Anthrax transmission occurs in one of two ways:

1. Contact with infected animals or animal products

2. As a result of bio-terrorism - Example: in 2001 Anthrax was deliberately spread through the postal system by sending letters containing anthrax powder. This caused 22 cases of Anthrax infections.

The CDC classifies agents into 3 priority areas. Anthrax is classified as a Category A agent. This means:

1. May spread across a large area, or require public awareness.

2. Pose the greatest possible threat for a bad effect on public health.

3. Require a great deal of planning to protect the public's health.

Anthrax refers to a pulmonary disease that is caused by the bacterium Bacillus anthracis. Humans can acquire anthrax from exposure to the natural reservoirs of the microorganism: livestock such as sheep or cattle or wild animals. Anthrax has been acquired by workers engaged in shearing sheep, for example.

Human anthrax can occur in three major forms.

• Cutaneous anthrax refers to the entry of the organism through a cut in the skin.
• Gastrointestinal anthrax occurs when the organism is ingested in food or water.
• Finally, inhalation anthrax occurs when the organism is inhaled.

The inhalation form of anthrax can occur because of the changing state of the organism. Bacillus anthracis can live as a large "vegetative" cell, which undergoes cycles of growth and division. Or, the bacterium can wait out it nutritional bad times by forming a spore and becoming dormant. The spore is designed to protect the genetic material of the bacterium during hibernation. When conditions are conducive for growth and reproduction the spore resuscitates and active life goes on again. The spore form can be easily inhaled. Only 8,000 spores, hardly enough to cover a snowflake, are sufficient to cause the pulmonary disease when they resuscitate in the warm and humid conditions deep within the lung.