Differential Diagnosis for Patient Exposed to Worms by Dog

• Single most likely diagnosis:
  • Toxocariasis: This is a common parasitic infection caused by the roundworms Toxocara canis or Toxocara cati, typically found in dogs and cats. The patient's concern about exposure to worms from their dog makes this a highly plausible diagnosis, given the direct route of potential transmission.
• Other Likely diagnoses:
  • Hookworm infection: Hookworms are another type of parasite that can be transmitted from dogs to humans, typically through contact with contaminated feces. Symptoms can include gastrointestinal issues and skin lesions.
  • Tapeworm infection: While less common, tapeworms (such as Echinococcus or Taenia species) can also be transmitted from dogs to humans, often through ingestion of eggs from contaminated feces.
• Do Not Miss diagnoses:
  • Echinococcosis (Hydatid disease): Although rare, this parasitic infection caused by Echinococcus species can lead to serious health issues, including cyst formation in organs like the liver or lungs. It is crucial not to miss this diagnosis due to its potential severity.
  • Baylisascaris infection: Caused by the raccoon roundworm, this infection is less likely if the patient specifically mentions exposure to their dog. However, it can lead to severe neurological symptoms and is worth considering to avoid missing a potentially deadly diagnosis.
• Rare diagnoses:
  • Dipylidium caninum infection: This tapeworm is typically transmitted to humans through the ingestion of infected fleas, which can be found on dogs. While rare, it's a possibility if the patient has been in close contact with their dog and has ingested an infected flea.
  • Strongyloidiasis: This infection, caused by the Strongyloides stercoralis parasite, is more commonly associated with exposure to contaminated soil rather than direct dog exposure. However, it can be considered in the differential diagnosis due to its potential for autoinfection and severe immunosuppressed cases.