Loa loa

Background

Epidemiology

• Transmitted by Chrysops silacea and Chrysops dimidiata flies

Clinical Presentation

• Often asymptomatic
• Most common symptom is Calabar swellings, a 10- to 20-cm painful, itchy subcutaneous swelling caused by migration of the adult worms
  • The lesions are essentially angioedema in response to the worm
• Worms can also migrate to the conjunctiva, where they are visible
• Infection can be complicated by hematuria and proteinuria, as well as as encephalitis, precipitated by treatment during high-level microfilaremia

Management

• Must rule out high-level microfilaremia (>2500 microfilariae/mL) before considering medical treatment, due to the risk of encephalitis