What is the treatment for elephantiasis (lymphatic filariasis)?

Treatment of Elephantiasis (Lymphatic Filariasis)

The treatment of elephantiasis (lymphatic filariasis) requires diethylcarbamazine (DEC) 6 mg/kg in 3 divided doses for 14 days plus doxycycline 200 mg daily for 6 weeks, with careful screening for co-infections before initiating therapy. 1

Diagnosis and Initial Assessment

Before initiating treatment, proper diagnosis is essential:

• Diagnostic tests:

  • Nocturnal blood microscopy (10 pm to 2 am in citrated blood bottles, not refrigerated)
  • Serology for filarial antigens
  • Check for microfilaremia levels (critical for treatment decisions)

• Critical pre-treatment screening:

  • Rule out onchocerciasis co-infection (skin snips and slit lamp exam)
  • Rule out loiasis co-infection (daytime blood microscopy)
  • These screenings are mandatory as DEC can cause severe reactions including blindness in onchocerciasis and encephalopathy in loiasis 1

Treatment Algorithm Based on Microfilarial Load

1. If microfilariae count < 1000 mf/ml:

• First-line treatment: DEC 6 mg/kg in 3 divided doses for 14 days plus doxycycline 200 mg daily for 6 weeks 1
• DEC can be given without steroid cover if peripheral blood is negative for microfilariae 1

2. If microfilariae count > 1000 mf/ml:

• Pre-treatment: Albendazole 200 mg twice daily for 21 days plus prednisolone (after screening for strongyloidiasis)
• Check microfilariae levels at day 28
• Repeat albendazole course until microfilariae level < 1000 mf/ml is achieved
• Then proceed with DEC with prednisolone cover 1

3. Alternative DEC dosing regimen:

• Day 1: 50 mg single dose
• Day 2: 50 mg three times daily
• Day 3: 100 mg three times daily
• Day 4 onward: 200 mg three times daily for 21 days 1

Special Considerations

• Co-infections:

  • If onchocerciasis is present: Avoid DEC; use doxycycline 200 mg daily for 6 weeks plus ivermectin 200 μg/kg monthly for 3 months 1
  • If loiasis is present: Seek expert advice; high microfilarial loads require careful management 1

• Monitoring:

  • Follow-up with day blood tests at 6 and 12 months after the last negative sample to monitor for relapse 1

• Duration of treatment for chronic elephantiasis:

  • Lymphedema may resolve within one year of treatment
  • Established elephantiasis may require 2-4 years of treatment for resolution 2
  • Arm elephantiasis responds better than leg elephantiasis
  • Unilateral leg elephantiasis responds better than bilateral
  • Shorter duration elephantiasis (< 3-5 years) responds better to treatment 2

Management of Chronic Lymphedema

For established elephantiasis, in addition to anti-parasitic treatment:

• Limb elevation
• Compression bandaging
• Meticulous skin hygiene to prevent secondary bacterial infections
• Regular exercise to promote lymphatic drainage
• Treatment of acute inflammatory episodes with antibiotics when needed

Pitfalls and Caveats

1. Never administer DEC without screening for onchocerciasis and loiasis in patients who have traveled to co-endemic areas, as this can lead to severe adverse reactions including blindness and encephalopathy 1

2. Microfilarial threshold determination is critical before treatment, as high microfilarial loads require different management approaches 1

3. Cross-reactivity in diagnostic testing can occur between filariasis and other helminth infections, particularly Strongyloides, potentially leading to misdiagnosis 3

4. Treatment expectations must be managed - while lymphedema may resolve within one year, established elephantiasis may take several years to improve 2

5. Adverse reactions to DEC are correlated with microfilarial load - higher loads lead to more severe reactions 4