7 September 2007
Cutaneous
Anthrax: Key References for Clinicians
This week two persons in Danbury, Connecticut (USA) were
diagnosed with cutaneous anthrax. The reported source of the infection is
imported animal hides being used to make African drums. Today’s New York Times
also reported that “six samples collected from a three-story house and a barn
in the backyard tested positive for anthrax… (Page A27, Sept 7, by Thomas
Kaplan)”
According to the Connecticut Post (ConnPost.com) article
September 5th by Robert Miller “staff from Danbury Hospital and the
state Department of Public Health emphasized the cases posed no health risk
whatsoever to the general public”.
This event can reinforce the importance for clinicians of
having useful references readily available with regard to cutaneous anthrax,
for example:
---The American College of Physicians (ACP) has posted on
their website a PowerPoint presentation with 60 slides titled “Cutaneous
Anthrax and its Mimics”. Most of the 20
diseases in the differential diagnosis of cutaneous anthrax also have photos
provided. Discussion of all 20 diseases ends with a final slide that helps
differentiate the disease from cutaneous anthrax. For example, the bite of the brown recluse
spider (Loxosceles reclusa) causes a painful lesion, whereas the lesion of
cutanous anthrax is PAINLESS. Also of
note, the brown recluse spider bite occurs mainly in the Midwest and Southeast
of the US and not in the northeast (e.g., Connecticut). These slides by the ACP
and American Society of Internal Medicine are posted at:
www.acponline.org/bioterro/#pflu
---The American Society of Dermatology (AAD) posted on their
website in November 2001 a detailed “Cutaneous Anthrax Management Algorithm”.
This document includes clinical pearls describing the typical appearance and
progression of cutaneous anthrax. For example, they note that “pustules are
rarely present in anthrax lesions”. Also, although the skin lesion is usually
PAINLESS the associated regional lymphadenopathy is usually “tender”. This document also provides specific detailed
advice on how best to obtain swab exudates and punch biopsies from the
lesion(s), including the type of swab to use, and where exactly to biopsy. This
algorithm is posted at: www.aad.org/professionals/educationcme/bioterrorism/CutaneousAnthrax.htm
--- The CDC anthrax webpage (at: www.bt.cdc.gov/agent/anthrax)
has a specific section on the diagnosis and management of cutaneous anthrax, as
well as images of cutaneous anthrax (at: www.bt.cdc.gov/agent/anthrax/anthrax-images/cutaneous.asp).
Additional images, cutaneous and microscopic, are also posted on the CDC’s
“Public Health Images Library (PHIL), with the largest number of skin photos on
page 5 of 8.
---The Infectious Diseases Society of America (IDSA) website
contains comprehensive information on all forms of anthrax (at: www.cidrap.umn.edu/idsa/bt/anthrax/biofacts/anthraxfactsheet.html)
This document includes images of cutaneous anthrax,
diagnostic steps, therapy and literature references.
---Additional images of cutaneous anthrax can be found on
the homepage of this website (www.BePast.org), as well as on the website of the E-Medicine
chapter on dermatologic aspects of anthrax (at: www.emedicine.com/derm/topic913.htm).
Without appropriate antibiotics the case-fatality rate has
been approximately 20%. Increased risk
of death is linked with airway compression due to a cutaneous lesion on the
neck (with characteristic extensive edema), or with the development of
bacteremia, especially if complicated by meningitis.
A discussion of all aspects of clinical anthrax is also
provided by this author in the most recent (6th) edition (2005) of
the textbook “Principles and Practice
of Infectious Diseases” edited by Mandell, Bennett, and Dolin (pages
2485-2491 and 3618-3624)
Daniel R. Lucey, MD, MPH
Director, Center for Biologic Counterterrorism and Emerging
Diseases
EROne Institutes, Department of Emergency Medicine
Washington Hospital Center
Adjunct Professor of Microbiology and Immunology
Georgetown University Medical Center, Washington, DC
Website for this posting: www.BePast.org
e-mail: Daniel.R.Lucey@Medstar.net