Tissue Nematodes Flashcards
What are cutaneous larva migrans?
Dermatitis caused by invasion of skin by dog and cat hookworm, Ancylostoma caninum/braziliense
You get it when bare skin touches contaminated soil containing hookworms
No deeper than the epidermis; causes a papule when the larva penetrates which develops into a serpinginous track when the larba wanders around; acutely inflammed, then becomes encrusted and scarred; pruritis (itching)
Treat with albendazole/ivermectin/topical thiabendazole
What is toxocariasis?
Caused by toxocara canis/catis (dog/cat roundworm)
Can cause visceral larva migrans or ocular larva migrans
You get it from ingesting eggs from dog/cat poop; these hatch in small intestine, penetrate mucosa, go to liver, causing granulomas, and can spread to other parts of tissue
Many are asymptomatic, but can cause visceral larval migrans and ocular larval migrans
What is visceral larva migrans?
Toxocara canis/catis in tissue (ingest egg from dog/cat poop) - larva enter viscera and wander
Inflammatory response to larva in liver/other tissues
High eosinophelia, leukocytosis, fever, hepatomegaly
Wheezing, coughing, neurologic manifestations
Diagnose with ELISA serology
Treat with Albenzazole/diethylcarbamazine/thiabendazole
What is ocular larva migrans?
Toxocara migrate to eyes
Causes blindness (unilateral), strabismus (cross eye), ocular pain, normal eosinophilia
Fewer infecting larva –> less immune response –> eye is randomly invaded
Diagnose with ELISA, treat wtih albendazole
What is baylisascariasis?
Caused by raccoon roundworm (imagine a raccoon in a bay leaf tree)
Causes a visceral larval migrans that primarily invades CNS and eye
You get it after ingesting eggs from raccoon poop
Causes acute eosinophilic meningoencephalitis & eye involvement
Diagnose by detecting larvae in tissues + serology
No known treatment
What is trichinosis?
Trichinella spiralis – eat encysted larva in undercooked pork
“Tricked into eating pork”
Enteral reaction (weeks): GI signs, due to invasion of mucosa
Parenteral reaction: Larvae form cysts in straited muscles, calcify –> myalgia, periorbital edema, eosinophilia, hemmorrhages in nail bed
Diagnose with serology, seeing larvae in muscle biopsy, eye microfilariae
Treat with Ivermectin
What is loiasis?
Eyeworm caused by loa loa (remember this because loa loa is 2 words = 2 eyes)
You get it from the red fly (central/west Africa) which infects a larva that develops into an adult worm
Adult worm causews transient subcutaneous Calabar swellings, urticaria (hives), migration through conjunctiva, meningoencephalitis = rare, associated with DEC treatment
Diagnose with blood smear (microfilariae)/serology
Treat with Diethylcarbamazine (DEC) which decreases arachidonic acid metabolism & kills adults+ microfilariae
What is onchocerciasis?
River blindness, caused by onchocerca volvulus
(Think “oncho” river)
Black fly = vector, infects larvae into the host
Gravid females produce 1000s of tissue invasive episodes of lymphedema which progresses to elephantiasis (swelling of lower body), hydrocele (swollen testicle)
Blindness, hanging groin, dematitis, leopard skin
Diagnose by skin slip, slit lamp for eye microfilariae, serology-ELISA
Treat with** ivermectin,** DEC**, **albendazole
What is Bancroftian filariasis?
Wucheria bancrofti
Mosquito vector –> larvae on skin –> develop to adults in lymphatic channels, microfilariae enter blood stream
Can cause different symptoms depending on the area
Acute lymphangitis w/ fever, chills, malaise
Pain, erythema, tenderness of affected lymph node
Elephantitis, hydrocele, chylurea (milky urine)
Diagnose with smear at midnight, serology (ELISA)
Treat with DEC
