Differential Diagnosis
- Single most likely diagnosis
- Anthrax: The patient's occupation with animal hides and the description of the lesion starting as a painless scrape that worsened over time are highly suggestive of cutaneous anthrax. The fact that anthrax can be acquired through contact with infected animal products supports this diagnosis.
- Other Likely diagnoses
- Brucellosis: Although less likely, brucellosis could be considered given the patient's exposure to animal hides. However, the clinical presentation typically involves systemic symptoms such as fever, fatigue, and swelling, which are not mentioned.
- Tularemia: This bacterial infection can cause skin ulcers and is associated with contact with infected animals or contaminated water. The presentation could fit, but it's less directly linked to the specific occupation and lesion description provided.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rabies: Although the primary mode of rabies transmission is through bites, it's theoretically possible for the virus to enter the body through an open wound if it comes into contact with infected saliva or tissue. Given the severity of rabies, it should not be overlooked, even if the likelihood is low based on the information provided.
- Rare diagnoses
- Leptospirosis: This infection is more commonly associated with water exposure and less directly linked to working with animal hides. The clinical presentation often includes systemic symptoms, making it a less likely consideration based on the provided scenario.
- Glanders: A rare bacterial infection that can cause skin lesions, but it's more commonly associated with direct contact with infected horses or other equines, making it less likely in this context.
Given the most likely diagnosis of anthrax, the appropriate post-exposure prophylaxis (PEP) would involve antibiotics. Among the options provided:
- B. Doxycycline is the correct choice for post-exposure prophylaxis against anthrax.
- C. Raxibacumab is an anthrax monoclonal antibody used for treatment, not typically for PEP.
- A. Penicillin and D. Rifampin are antibiotics but not the first choice for anthrax PEP in this context.