| • | in an acutely ill patient |
| • | Braverman: gram (-) sepsis (embolic phenomenon to skin) |
| • | starts with a gunmetal gray, infarcted lesion with surrounding erythema |
| • | evolves into a necrotic black eschar, usually painless, or patients is too sick to focus on the local problem |
| • | frequently but not exclusively, the lesion is in the anogenital or axillary region |
| • | culture of lesions and blood almost always positive |
| • | gram stain vesicle fluid gram (-) rods |
| • | histology – distinctive finding in pseudomonas lesion is a necrotizing vasculitis in which the walls of small arteries are invaded by a myriad of bacteria (but thrombosis is unusual?) |
| • | ddx of Pseudomonas septicemia (includes other infections that can produce skin lesions through direct involvement of blood vessels (e.g. N. meningitides, E. coli, Klebsiella pneumoniae, and fungi of Aspergillus and Rhizopus group)) |
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