Lymphatic filariasis

Background

  • Also known as elephantiasis
  • Causative agents (transmitted by mosquito):
    • Wuchereria bancrofti
    • Brugia malayi
    • Brugia timori
  • No known natural animal reservoir[1]
  • Larvae migrate to lymphatic vessels and mature into adults (can take 6-12 months[1])
    • These worms block lymphatic vessels, which causes the clinical presentation of the disease
  • Coinfection is common (filiariae cause immunosuppression and allows for malaria and/or TB to thrive)

Clinical Features

  • 2/3 will be asymptomatic[2]
  • Chronic infection leads to massive peripheral edema with thickening of overlying skin particularly in lower extremities and genitalia
  • Recurrent cellulitis is common

Differential Diagnosis

Evaluation

  • Establish possible exposure in endemic areas
  • Serology (peripheral blood) - draw at night due to periodicity of filiariae
  • Tests for W. bancrofti
    • PCR
    • Antigen detection
    • Ultrasound may occasionally show movement of adult filiariae

Management

  • Diethylcarbamazine (DEC):
    • Day 1: 50mg PO
    • Day 2: 50mg TID
    • Day 3: 100mg TID
    • Days 4-21: 6mg/kg/day divided TID
  • Ivermectin + Albendazole
  • Combined treatment with diethylcarbamazine/albendazole may be more effective than single drug treatment
  • Meticulous skin care to prevent superinfection/cellulitis
  • Surgical management of scrotal elephantiasis and chronic lymphatic obstruction

Disposition

  • Generally may be discharged unless complicated by other factors.

See Also

External Links

References

  1. 1.0 1.1 Chandy A, Thakur AS, Singh MP, Manigauha A. A review of neglected tropical diseases: filariasis. Asian Pac J Trop Med. 2011 Jul;4(7):581-6. doi: 10.1016/S1995-7645(11)60150-8.
  2. Mark J Taylor, Achim Hoerauf, Moses Bockarie. Lymphatic filariasis and onchocerciasis. Lancet 2010; 376: 1175–85