Epidemiology

Etiology

Pathogen: Trypanosoma cruzi
Route of infections
- Vector transmission
  - Numerous triatomine species of the Reduviidae family (also called kissing bug because it typically bites around the mouth)
    - They hide in the cracks of houses and usually bite individuals in their sleep.
  - T. cruzi is shed in the feces of the reduviid bug; feces is then rubbed into the bite site while scratching.

Acute phase
- Cutaneous manifestations
  - Chagoma: inflammatory edema at the bite site (usually in the face)
  - Romana sign: unilateral painless edema of the eyelids and periocular tissue
    - Romana sign is seen when the portal of entry of T. cruzi is the conjunctiva. Patients may also present with ipsilateral conjunctivitis and preauricular lymph node enlargement.

Best initial test: direct visualization of T. cruzi trypomastigotes in thin and thick peripheral blood smears using a Giemsa stain