Lymphatic filariasis
Alerts and Notices
Synopsis
Approximately 50% of infections are asymptomatic. The remainder of infections represent either acute lymphatic inflammation or chronic lymphatic obstruction resulting in hydrocele or lymphedema of the limbs.
Acute filariasis is characterized by acute adenolymphangitis, lymphadenitis, and episodic fever ("filarial fever"). Due to chronic lymphatic vessel inflammation and scarring, chronic infection eventually results in primarily asymmetric swelling of the extremities, male genitalia (ie, hydrocele), and breasts in women. Chronic lymphatic disease is rare in children younger than 10 years, but risk increases with age.
Patients from endemic areas may occasionally experience chyluria (milky urine) as renal lymphatics are blocked. Additionally, acute and chronic infection may be associated with tropical pulmonary eosinophilia and peripheral eosinophilia.
The disease course can be prolonged over years to decades.
Codes
ICD10CM:B74.9 – Filariasis, unspecified
SNOMEDCT:
240820001 – Lymphatic filariasis
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
AcuteFilarial fever and acute lymphadenopathy must be differentiated from other causes of tropical fevers and lymphadenopathy (eg, bacterial lymphangitis), and common viral infections (eg, influenza, mononucleosis, HIV).
Chronic
Extremity:
- Podoconiosis (nonfilarial lymphedema) – Usually bilateral and seen in regions with altitudes higher than 1500 meters.
- Other causes of lymphedema, such as congestive heart failure, deep venous thrombosis, and nephrotic syndrome, should be considered.
- Other causes of lymphatic obstruction, such as pelvic tumors, should be considered.
- Nonfilarial hydrocele – Indistinguishable clinically from filarial hydrocele.
- Onchocerciasis – Redundant loose skin over the groin ("hanging groin").
- Inguinal hernia – Increases with cough / Valsalva manuever.
- Scabies – Often nodular in the genital region, and burrows may be present.
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:09/16/2020
Last Updated:09/22/2020
Last Updated:09/22/2020
Lymphatic filariasis