Snapshot A 5-year-old boy is brought to his pediatrician for abnormal scratching behavior. His mom reports that he has been scratching his anus for the past few days, causing some concern among his schoolteachers. His bowel movements and appetite have been normal. On physical exam, there is some erythema and excoriations from scratching around his anus. His pediatrician conducts a scotch tape test and identifies eggs on microscopy. He is given the correct anti-helminthic therapy. Introduction Introduction helminths are macroscopic parasitic worms tapeworms (cestodes) flukes (trematodes) roundworms (nematodes) roundworms (nematodes) organism characteristics transmission ingestion of eggs/larvae Enterobius Ascaris Toxocara Trichuris Trichinella Dracunculus invasion of larvae cutaneously Strongyloides Ancylostoma Necator arthropod bites Loa loa Onchocerca volvulus Wuchereria bancrofti treatment most are treated with bendazoles other options include ivermectin or diethylcarbamazine Roundworms (Nematodes) Organism Clinical Presentation Transmission Treatment Transmission by Ingestion of Eggs Enterobius vermicularis (pinworm) Anal pruritus, especially in children Scotch tape test scotch tape to anal area will show eggs on microscopy Most common helminth parasite in the US Fecal-oral Ingestion of eggs Bendazoles Pyrantel pamoate Ascaris lumbricoides (giant roundworm) Biliary obstruction Intestinal obstruction or perforation May also affect the lungs Oval eggs are seen on stool microscopy Fecal-oral Ingestion of eggs Migrates from the nose/mouth to intestines Bendazoles Toxocara canis Visceral larva migrans Myocarditis, liver damage, ocular damage (visual impairment and blindness), and brain damage (seizures and coma) Granuloma formation causes damage Fecal-oral Ingestion of eggs Migrates from intestinal wall to blood Bendazoles Trichuris trichiura (whipworm) Microcytic anemia Abdominal pain and diarrhea Can cause intestinal/rectal prolapse in children Fecal-oral Ingestion of eggs Bendazoles Transmission by Ingestion of Larvae Trichinella spiralis Trichinosis Fever, vomiting, nausea, periorbital edema, and myalgia Undercooked meat Ingestion of larvae (the only nematode transmitted this way) Migrates from blood to striated muscle, causing inflammation Bendazoles Transmission by Cutaneous Penetration Strongyloides stercoralis (threadworm) Gastrointestinal upset Pneumonitis Loffler syndrome Dermatitis Rhabditiform larvae, not eggs, seen on stool microscopy Penetration from soil into the skin Bendazoles Ivermectin Ancylostoma braziliense Necator americanus (hookworm) Microcytic anemia Cutaneous larva migrans or "creeping eruption" that moves as the larvae moves Pruritic serpiginous rash Penetration into the skin, often from walking barefoot on the beach Nematode sucks blood from the intestinal wall Bendazoles Pyrantel pamoate Transmission by Arthropods (Bite or Ingestion) Wucheria bancrofti Lymphatic filariasis or elephantiasis Lymphedema causing disfiguration of extremities Via female mosquitoes Invades lymph nodes Diethylcarbamazine Loa loa (African eye worm) Calabar swellings in skin Worms in conjunctiva Via deer flies, horse flies, and mango flies Diethylcarbamazine Onchocerca volvulus Hyperpigmented rash, river blindness, and black skin nodules Via female blackflies Ivermectin (Rivermectin) Dracunculus medinensis (Guinea worm) Skin inflammation and ulceration Worm eruption from skin Anaphylactic shock if worm is pulled from skin and breaks, due to release of foreign antigens Ingestion of water contaminated with infested water fleas Niridazole Removal of worm that has emerged from skin, by a few cms each day using a rod
QUESTIONS 1 of 7 1 2 3 4 5 6 7 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.MC.17.4817) A 32-year-old woman in Florida presents to your office with abdominal pain and bloating over the last month. She also complains of intermittent, copious, non-bloody diarrhea over the same time. Last month, she first noticed a small rash on her leg, and then developed a cough that has since improved but has not completely resolved. She has no sick contacts and has not left the country recently. Physical examination is notable for a small pink streak on her right leg. Serum laboratory studies are pending. Examination of her stool reveals the causative organism. This organism is most likely transmitted to the human host through which of the following routes? QID: 109392 Type & Select Correct Answer 1 Inhalation 20% (33/166) 2 Penetration of skin 55% (92/166) 3 Animal bite 16% (26/166) 4 Insect bite 2% (4/166) 5 Sexual contact 5% (8/166) M 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (1) Login to View Community Videos Login to View Community Videos Toxocara Canis Keshav Mudgal Microbiology - Roundworms (Nematodes) D 12/5/2015 111 views 5.0 (2)