Cutaneous Anthrax
The primary lesion is a painless, pruritic papule that appears from one to seven days after inoculation. Within one to two days, small vesicles or a larger, 1 to 2 cm vesicle forms and is filled with clear or serosanguineous fluid. As the vesicle enlarges, satellite vesicles may form. Fluid within the vesicles may contain numerous, large gram-positive bacilli. As the lesion matures, a prominent, non-pitting edema surrounds the lesion. Eventually, the vesicle ruptures, undergoes necrosis, and enlarges, forming an ulcer covered by the characteristic black eschar. Symptoms include low-grade fever, malaise. Regional lympadenopathy is present early on.
Recognition and Management of Anthrax—An Update

Used with Permission from the Center for Public Health and Disasters of California
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