Hymenolepis nana
Background
- Dwarf tapeworm - named so because it is smaller than most cestodes
- Most common human tapeworm infection worldwide
- Transmission through poor sanitation and hygiene
- Completes its entire life cycle in a single host
Clinical Features
- Most common in children
- Majority of infections are asymptomatic
- As parasite burden increases symptoms become more likely
- Presents with crampy abdominal pain, diarrhea, anorexia, and anal pruritus
- May also exhibit dizziness, irritability, sleep disturbance, and seizures
Differential Diagnosis
- Amebiasis
- Colitis
- Diphyllobothrium latum Infection
- Giardiasis
- Hookworm Infection
- Intestinal Protozoal Diseases
- Cystoisosporiasis
- Pediatric Malabsorption Syndromes
- Shigella Infection
- Yersinia enterocolitica
Helminth infections
Cestodes (Tapeworms)
- Taenia saginata
- Taenia solium (Cysticercosis)
- Diphyllobothrium latum
- Hymenolepis nana
- Echinococcus granulosus
Trematodes (Flukes)
- Fasciola hepatica
- Fasciolopsis buski
- Opistorchis viverrini
- Schistosoma spp
- Chlonorchis sinensis
- Paragonimus spp.
Nematodes (Roundworms)
- Ascaris lumbricoides
- Enterobius vermicularis (Pinworm)
- Filarial worms
- Hookworm
- Necator americanus
- Ancylostoma duodenale
- Cutaneous larva migrans (Ancylostoma braziliense)
- Dracunculiasis
- Strongyloides stercoralis
- Trichuris trichiura (Whipworm)
- Anisakis
- Toxocara spp.
- Trichinosis
Evaluation
- History of above symptoms +/- local exposure
- Peripheral blood eosinophilia of 5 to 10% may be observed
- Definitive diagnosis by identifying eggs or proglottids in the stool
- Diagnosis of hymenolepiasis should prompt family screening or empiric treatment
Management
Praziquantel: 25mg/kg orally (single dose), followed by repeat dose 10 days later
Disposition
- Discharge with follow up and plan to either screen or treat family and close contacts