Schistosomiasis vs Other helminth infections
How to tell Schistosomiasis and Other helminth infections apart when a board question makes them look alike.
Schisto is freshwater skin penetration with venous eggs causing portal/bladder disease; other helminths are keyed by autoinfection, perianal itch, anemia, obstruction, or cysts.
Side by side
Schistosomiasis follows freshwater exposure where cercariae penetrate skin, causing swimmer itch, Katayama fever, eosinophilia, portal hypertension or hematuria depending on species.
Other helminths are separated by route and syndrome: Strongyloides autoinfection/hyperinfection, Ascaris intestinal/lung migration, Enterobius perianal itching, hookworm iron deficiency, and Taenia/neurocysticercosis.
Adult Schistosoma worms live in venous plexuses; eggs trigger granulomatous inflammation in liver/intestine or bladder.
Helminths cause disease through tissue migration, nutrient/blood loss, intestinal obstruction, autoinfection, or cyst formation depending on species.
Freshwater exposure, eosinophilia, eggs in stool or urine, hepatosplenic disease, terminal hematuria, and bladder squamous cell carcinoma risk support schistosomiasis.
Larva currens/hyperinfection supports Strongyloides; nocturnal perianal itch supports Enterobius; iron-deficiency anemia supports hookworm; seizures/cysts support neurocysticercosis.
The trap
Eosinophilia only says helminth/allergy; exposure route and egg/tissue syndrome identify the organism.
The repair move
For helminth infections, start with exposure route and locate the worm or egg injury: (1) SCHISTOSOMIASIS (Schistosoma mansoni and japonicum cause portal hypertension with periportal pipe-stem fibrosis from egg deposition in mesenteric veins; Schistosoma haematobium causes bladder fibrosis and a 10-fold increase in bladder squamous cell carcinoma) freshwater snail intermediate host in Africa and Middle East, cercariae penetrate skin; treat with praziquantel; (2) NEMATODES Enterobius (pinworm): nocturnal perianal itch in children, Scotch tape test, treat with albendazole or pyrantel pamoate; Ascaris: large round worm passed in stool, can cause biliary obstruction; Strongyloides: autoinfection, immunocompromise risk of hyperinfection (ivermectin); Hookworm (Ancylostoma, Necator): iron deficiency anemia from gut blood loss, soil penetration through bare feet (ground itch); (3) CESTODES (tapeworms) Taenia solium: cysticercosis from undercooked pork or eggs, brain cysts cause neurocysticercosis seizures; Echinococcus: hydatid liver cysts from dog tapeworm (sheep-raising areas), eggshell calcification, treat with surgery + albendazole; Diphyllobothrium latum: fish tapeworm causes B12 deficiency.
Try a free question
CoreA traveler swims in freshwater in Africa and later develops hematuria, eosinophilia, and urine eggs with a terminal spine. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Schistosomiasis. Freshwater exposure with skin penetration risk, hematuria, eosinophilia, and terminal-spined urine eggs supports Schistosoma haematobium.
Why the other choices are tempting
- B. Strongyloides causes autoinfection and hyperinfection risk.
- C. Enterobius causes nocturnal perianal itching.
- D. Hookworm causes iron-deficiency anemia after skin penetration from soil.
- E. Neurocysticercosis causes seizures from Taenia solium larvae in CNS.
Flashcards
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How does Schistosoma enter humans?
Schistosoma cercariae penetrate skin during freshwater exposure.
What causes pathology in schistosomiasis?
Egg-driven granulomatous inflammation causes much of the pathology in schistosomiasis.
Quick answers
What is the fastest way to tell Schistosomiasis from Other helminth infections?
Schisto is freshwater skin penetration with venous eggs causing portal/bladder disease; other helminths are keyed by autoinfection, perianal itch, anemia, obstruction, or cysts.
What is the key clue for Schistosomiasis?
Schistosomiasis follows freshwater exposure where cercariae penetrate skin, causing swimmer itch, Katayama fever, eosinophilia, portal hypertension or hematuria depending on species.
What is the key clue for Other helminth infections?
Other helminths are separated by route and syndrome: Strongyloides autoinfection/hyperinfection, Ascaris intestinal/lung migration, Enterobius perianal itching, hookworm iron deficiency, and Taenia/neurocysticercosis.
What is the common trap with Schistosomiasis vs Other helminth infections?
Eosinophilia only says helminth/allergy; exposure route and egg/tissue syndrome identify the organism.