Filariasis is a parasitic infection caused by filarial worms. It is commonly spread by mosquitoes and certain flies. Patients may often be asymptomatic or present with wide range of symptoms such as fever, groin pains, leg swelling or swollen lymph nodes. One of the commonest presentations is chronic cough with eosinophilia. In extreme cases patients may present with elephantiasis and lymphoedema.
Lymphatic filariasis:
Medications in acute phase (new onset fever and unilateral leg swelling):
- Tab. Doxol LB (Doxycycline 100 mg, 5 billion Lactobacillus spores) – one tablet twice a day for 4 weeks.
Medications after acute phase subsides (stepwise treatment):
Step 1 –
- Day 1 to 4 – Tab. Montina-L (Montelukast 10 mg, Levocetirizine 5 mg) – one tablet once a day in the evening.
- Day 2 – Tab. Ivermectol 12 (Ivermectin 12 mg) – one tablet once a day as single dose (contraindicated in pregnancy).
Step 2 –
Start tab. Medrol (Methylprednisolone) 8mg and 4mg tablets –
- Day 1: 24 mg orally (8 mg before breakfast; 4 mg after lunch; 4 mg after dinner; 8 mg at bedtime)
- Day 2: 20 mg orally (4 mg before breakfast; 4 mg after lunch; 4 mg after dinner; 8 mg at bedtime)
- Day 3: 16 mg orally (4 mg before breakfast; 4 mg after lunch; 4 mg after dinner; 4 mg at bedtime)
- Day 4: 12 mg orally (4 mg before breakfast; 4 mg after lunch; 4 mg at bedtime)
- Day 5: 8 mg orally (4 mg before breakfast; 4 mg at bedtime)
- Day 6: 4 mg orally (4 mg before breakfast)
Always give steroids with PPI cover i.e Pantakind (pantoprazole 20mg).
Tab. Hetrazan (Diethylcarbamazine 100 mg) –
- Day 1 and 2 – no treatment to provide initial steroid cover
- Day 3 – Half tablet once a day
- Day 4 – Half tablet twice a day
- Day 5 – One tablet twice a day
- Day 6 to 21 – One tablet thrice a day
Subcutaneous filariasis [Loa loa infection or onchocerciasis (river blindness)]
- Tab. Ivermectol 12 (Ivermectin 12 mg) – one tablet once a day as single dose. Repeat dose after 3 months. Repeat the treatment every 12 months. Contraindicated in children less than 5 years or less than 15 kgs and pregnant women.
- Diethylcarbamazine is contraindicated for subcutaneous filariasis.
General advice:
- Ensure cleanliness of surrounding area to reduce mosquito breeding.
- Advice good general hygiene measures
- Ensure good hydration
- Advice leg stockings to improve lymphatic drainage
Investigations:
- Peripheral smear for microfilariae between 9pm and 3am
- Skin biopsy for subcutaneous infections
- Complete blood count – look for eosinophilia
- Renal function test and Liver function test
- Urine and stool routine analysis