Lymphatic filariasis: Difference between revisions

Revision as of 23:23, 28 August 2020

Background

Mosquito-borne infection by filarial parasites causing chronic progressive lymphedema

Microbiology

Wuchereria bancrofti (most common, worldwide)
Brugia malayi and Brugia timori (Asia)

Epidemiology

Transmitted by various species of mosquitoes, including Anopheles species, Culex species, Aedes species, and Mansonia species
Present in Africa, Asia, Indian subcontinent, western Pacific Islands, areas in South and Central America, and the Caribbean (particularly Haiti and the Dominican Republic)
Brugia malayi is present in India, Malaysia, and western Pacific islands including Indonesia and the Philippines
- Has animal reservoirs in cats and primates
Brugia timori is in the islands of southeastern Indonesia

Clinical Manifestations

Acute Manifestations

Acute Filarial Lymphangitis

Pain, erythema, and tenderness in the regional lymph node, followed by lymphangitis that spreads distally
Caused by inflammation from the death of an adult worm

Acute Dermatolymphangioadenitis

Bacterial infection of the small lymphatics causing fevers, chills, and pain
Often diagnosed as cellulitis, and can have a reticular pattern (compared to linear, in AFL)
May have history of preceding trauma or injury

Brugian Adenolymphangitis

A single abscess along the lymphatics that can drain and scar

Tropical Pulmonary Eosinophilia

Hypersensitivity response to the filaria migrating through the lungs
Mostly occurs in India but also Pakistan, Sri Lanka, Brazil, Guyana, and Southeast Asia
More common in men aged 20 to 40 years
Causes a paroxysmal non-productive cough, more severe at night (during microfilaremia), with wheezing, low-grade fever, adenopathy, malaise, and weight loss
Eosinophils usually very high, above 3, as well as high IgE titres and anti-filarial antibody titres
Chest x-ray can be normal or show diffuse small infiltrates with increased bronchovascular markings
Can progress to restrictive lung disease and diffuse interstitial fibrosis

Chronic Manifestations

Genital Manifestations

Only occur with Wuchereria bancrofti
Hydrocele, epididymitis, orchitis, funiculitis, lymphedema of the scrotum or vulva

Lymphedema and Elephantiasis

Lymphedema in the legs, genitals, breast, arms
More common in the legs, and usually asymmetric
- Whole limb is involved in bancroftian filariasis
- Distal limb is involved in brugian filariasis
Progresses to elephantiasis over years
- Repeated episodes ADLA, burden of filariasis in the population, and presence of Wolbachia species are risk factors for progression
WHO grading
- Grade I: pitting edema that is reversible with elevation of the extremity
- Grade II: non-pitting edema that is not reversible with elevation of the extremity
- Grade III: non-pitting edema that is not reversible with elevation and is associated with thickened skin or skin folds
- Grade IV: non-pitting edema with fibrotic and papillomatous skin lesions and the presence of skin folds (elephantiasis)

Chyuria

Caused by rupture of retroperitoneal lymphatics into the renal pelvis
Painless

@@ Line 1: / Line 1: @@
-== Background ==
+==Background==
 *Mosquito-borne infection by filarial parasites causing chronic progressive lymphedema
@@ Line 8: / Line 8: @@
 *''[[Brugia malayi]]'' and ''[[Brugia timori]]'' (Asia)
+=== Epidemiology ===
-== Clinical Manifestations ==
+* Transmitted by various species of mosquitoes, including [[Vector::Anopheles species]], [[Vector::Culex species]], [[Vector::Aedes species]], and [[Vector::Mansonia species]]
-=== Acute Manifestations ===
+* Present in Africa, Asia, Indian subcontinent, western Pacific Islands, areas in South and Central America, and the Caribbean (particularly Haiti and the Dominican Republic)
+* [[Brugia malayi]] is present in India, Malaysia, and western Pacific islands including Indonesia and the Philippines
+** Has animal reservoirs in cats and primates
+* [[Brugia timori]] is in the islands of southeastern Indonesia
+==Clinical Manifestations==
-==== Acute Filarial Lymphangitis ====
+===Acute Manifestations===
-* Pain, erythema, and tenderness in the regional lymph node, followed by lymphangitis that spreads distally
-* Caused by inflammation from the death of an adult worm
-==== Acute Dermatolymphangioadenitis ====
+====Acute Filarial Lymphangitis====
+*Pain, erythema, and tenderness in the regional lymph node, followed by lymphangitis that spreads distally
-* Bacterial infection of the small lymphatics causing fevers, chills, and pain
+*Caused by inflammation from the death of an adult worm
-* Often diagnosed as cellulitis, and can have a reticular pattern (compared to linear, in AFL)
-* May have history of preceding trauma or injury
-==== Brugian Adenolymphangitis ====
+====Acute Dermatolymphangioadenitis====
-* A single abscess along the lymphatics that can drain and scar
+*Bacterial infection of the small lymphatics causing fevers, chills, and pain
+*Often diagnosed as cellulitis, and can have a reticular pattern (compared to linear, in AFL)
+*May have history of preceding trauma or injury
+====Brugian Adenolymphangitis====
-==== Tropical Pulmonary Eosinophilia ====
+*A single abscess along the lymphatics that can drain and scar
-* Hypersensitivity response to the filaria migrating through the lungs
-* Mostly occurs in India but also Pakistan, Sri Lanka, Brazil, Guyana, and Southeast Asia
-* More common in men aged 20 to 40 years
-* Causes a paroxysmal non-productive cough, more severe at night (during microfilaremia), with wheezing, low-grade fever, adenopathy, malaise, and weight loss
-* Eosinophils usually very high, above 3, as well as high IgE titres and anti-filarial antibody titres
-* Chest x-ray can be normal or show diffuse small infiltrates with increased bronchovascular markings
-* Can progress to restrictive lung disease and diffuse interstitial fibrosis
+====Tropical Pulmonary Eosinophilia====
-=== Chronic Manifestations ===
+*Hypersensitivity response to the filaria migrating through the lungs
-==== Genital Manifestations ====
+*Mostly occurs in India but also Pakistan, Sri Lanka, Brazil, Guyana, and Southeast Asia
+*More common in men aged 20 to 40 years
+*Causes a paroxysmal non-productive cough, more severe at night (during microfilaremia), with wheezing, low-grade fever, adenopathy, malaise, and weight loss
+*Eosinophils usually very high, above 3, as well as high IgE titres and anti-filarial antibody titres
+*Chest x-ray can be normal or show diffuse small infiltrates with increased bronchovascular markings
+*Can progress to restrictive lung disease and diffuse interstitial fibrosis
+===Chronic Manifestations===
-* Only occur with [[Wuchereria bancrofti]]
-* Hydrocele, epididymitis, orchitis, funiculitis, lymphedema of the scrotum or vulva
+====Genital Manifestations====
-==== Lymphedema and Elephantiasis ====
+*Only occur with [[Wuchereria bancrofti]]
-* Lymphedema in the legs, genitals, breast, arms
+*Hydrocele, epididymitis, orchitis, funiculitis, lymphedema of the scrotum or vulva
-* More common in the legs, and usually asymmetric
-** Whole limb is involved in bancroftian filariasis
-** Distal limb is involved in brugian filariasis
-* Progresses to elephantiasis over years
-** Repeated episodes ADLA, burden of filariasis in the population, and presence of [[Wolbachia species]] are risk factors for progression
-* WHO grading
-** Grade I: pitting edema that is reversible with elevation of the extremity
-** Grade II: non-pitting edema that is not reversible with elevation of the extremity
-** Grade III: non-pitting edema that is not reversible with elevation and is associated with thickened skin or skin folds
-** Grade IV: non-pitting edema with fibrotic and papillomatous skin lesions and the presence of skin folds (elephantiasis)
-==== Chyuria ====
+====Lymphedema and Elephantiasis====
+*Lymphedema in the legs, genitals, breast, arms
-* Caused by rupture of retroperitoneal lymphatics into the renal pelvis
+*More common in the legs, and usually asymmetric
-* Painless
+**Whole limb is involved in bancroftian filariasis
+**Distal limb is involved in brugian filariasis
+*Progresses to elephantiasis over years
+**Repeated episodes ADLA, burden of filariasis in the population, and presence of [[Wolbachia species]] are risk factors for progression
+*WHO grading
+**Grade I: pitting edema that is reversible with elevation of the extremity
+**Grade II: non-pitting edema that is not reversible with elevation of the extremity
+**Grade III: non-pitting edema that is not reversible with elevation and is associated with thickened skin or skin folds
+**Grade IV: non-pitting edema with fibrotic and papillomatous skin lesions and the presence of skin folds (elephantiasis)
+====Chyuria====
+*Caused by rupture of retroperitoneal lymphatics into the renal pelvis
+*Painless
 [[Category:Nematodes]]