Pruritic macule on the fingers that ulcerates and forms multiple bloody vesicles followed by a painless black eschar. Which disease is this?

• A. Bubonic Plague
• B. Cutaneous Anthrax
• C. Dengue Fever
• D. Leptospirosis

Answer: (B)

The key idea is recognizing the characteristic skin lesion of cutaneous anthrax. Inoculation of Bacillus anthracis spores into the skin typically starts as a pruritic macule on the hands or fingers that progresses to vesicles or bullae and then rapidly forms a painless, black eschar. The surrounding edema is common, and the eschar is notable for being painless despite the tissue necrosis, due to the toxins produced by the bacteria.

This pattern helps distinguish it from the other conditions: bubonic plague would present with painful swollen lymph nodes (bubo) rather than a black eschar; dengue fever features fever, headache, myalgias, and rash without a necrotic eschar; leptospirosis presents with fever, myalgias, jaundice, or renal/multiorgan involvement rather than a necrotic skin lesion.