Lymphatic filariasis is a mosquito-borne parasitic infection. Over time it can damage lymph drainage and contribute to swelling of a limb, elephantiasis, hydrocele and painful episodes with fever.
Infection may remain outwardly silent for years. Once chronic swelling develops, care extends beyond antiparasitic medicine to skin protection, movement, infection prevention and follow-up.
How filariasis spreads
Infected mosquitoes transmit filarial parasites. Adult worms can live in lymphatic vessels, while microscopic larvae called microfilariae may circulate in blood. Mosquitoes can acquire the larvae from an infected person and continue transmission.
Touching a patient, sitting together, sharing meals or ordinary household contact does not spread filariasis.
Can infection be symptom-free?
Yes. A person may have no visible swelling despite a positive microfilaria or antigen report. Absence of symptoms does not justify ignoring a result; the test needs interpretation in its clinical context.
Symptoms and early signs
Possible features include recurrent fever, tender groin or other lymph nodes, sudden painful red-hot limb swelling, gradually increasing swelling, scrotal enlargement or hydrocele, thickened skin, toe-space cracks, fungal infection or wounds. Selected filarial presentations can involve cough, wheeze and markedly raised eosinophils.
These symptoms have other possible causes. A symptom list alone cannot establish the diagnosis.
Elephantiasis and lymphoedema
Lymph vessels remove extra tissue fluid. Damage can lead to chronic swelling, skin thickening and difficulty with daily activity. Small cracks or fungal infection can let bacteria enter damaged tissue.
Why painful attacks recur
Acute attacks of fever, pain, redness and swelling can arise from secondary bacterial infection on top of existing lymphatic damage. A recurrent episode does not automatically mean that the parasite has returned. Assessment includes skin entry lesions, fungal infection and other causes.
Which tests are used?
A timed peripheral blood smear looks for circulating microfilariae under a microscope. For some parasites, collection timing matters.
Filarial antigen testing can support diagnosis of Wuchereria bancrofti in an appropriate setting. An antigen test and a microfilaria smear answer different questions.
Depending on symptoms, a clinician may consider CBC, eosinophils, ultrasound or evaluation of heart, kidney, liver, veins, thyroid and other causes of swelling. Not every swollen leg is filariasis.
Three parts of treatment
- Infection treatment where indicated, with an individually selected antifilarial regimen.
- Assessment and treatment of an acute painful attack or secondary infection.
- Long-term care for swelling, skin changes and disability prevention. Hydrocele may need surgical assessment.
DEC, albendazole, ivermectin, doxycycline and antibiotics have different roles. Do not combine or repeat them from an old prescription. Community mass-drug-administration programmes are public-health measures and do not replace individual clinical care.
Five daily-care steps
Wash gently with clean water and mild soap. Dry toe spaces and folds carefully. Check for cracks, wounds, redness, fungal infection and discharge. Wear protective footwear that does not rub. Use suitable gentle movement and comfortable elevation as advised.
During an acutely red-hot painful episode, avoid vigorous massage or exercise. Progress can mean fewer attacks, healthier skin and better movement even when long-standing swelling persists.
When urgent care is needed
Seek prompt assessment for rapidly spreading redness, severe pain, high fever, confusion, fainting, pus, darkening skin, sudden severe scrotal pain, breathing difficulty or abrupt major swelling.
Prevention and family support
Mosquito nets, repellents, environmental mosquito control and participation in eligible public-health programmes can help. Family support makes daily skin care and follow-up easier.
Hindi videos from Dr. Pratyush Kumar
- Filariasis: causes, symptoms and treatment
- Microfilaria and antigen tests
- Recurrent attacks and MMDP care
- Wound care and exercise
See filariasis care in Patna and appointment locations.
Sources
This article is for health education and does not replace an individual medical consultation. Symptoms, test results, medicines, and treatment decisions should be discussed with a qualified clinician.
Seek urgent medical care for severe breathing difficulty, chest pain, confusion, fainting, uncontrolled bleeding, severe dehydration, or rapidly worsening symptoms.