A 48 year old cattle farmer presents with multiple painless black lesions on his right arm. Two weeks ago he had accidentally grazed his right arm on a farm tool. A few days later, pruritic papules appeared at that sites. These subsequently progressed into larger lesions surrounded by edema, over the following weeks. His medical, surgical and drug histories are unremarkable. He does not smoke or consume alcohol, and denies abuse of prescription drugs.
The gram stain reveals large, square-ended, gram-positive rods growing in chains, containing oval, central to subterminal spores. After 24h, cultures reveal dull, flat, white-grey non-hemolytic colonies, consistent with Bacillus anthracis.
Gram stain: Normal upper respiratory flora Culture results will be available in 3 days.
Appearance: clear Polymorphs: nil (< 5) Gram stain: negative Glucose: 70 mg/dL (50 - 80) Protein: 50 mg/dL (15 - 60)
Culture results will be available in 3 days.