In addition to Pseudomonas aeruginosa, can also be caused less commonly by Staph, Mucor, Candida, and Herpes
Diagnosis
Skin Biopsy: quite characteristic, showing bacterial invasion of the media and adventitia of veins deep in the dermis (intima and lumen of the vein are spared)
Clinical
Begins as red/purpuric macular rash -> progresses to indurated vesicles -> progresses to bullous, pustular, or hemorrhagic lesions -> gangrenous ulcers with surrounding erythema (may occur within 12-24 hrs)
Usually less than 10 lesions are present, most often found in the gluteal or perineal regions, but also appearing on the extremities, trunk, and face in descending order, respectively
Treatment
Aminoglycoside + Antipseudomonal PCN:
Ceftazidime:
Imipenem:
Surgical Debridement: often required
Prognosis
The lower the absolute neutrophil count (ANC), the poorer the prognosis
Patients with an ANC < 500 cells/mm3 (0.5 x 109/L) rarely survive
