238.2 📚 國考版

238.2.0.1 必背 — 4 Main STH

Worm	Skin / Egg	Lung Migration	Treatment
Ascaris	Eggs ingested	YES (Loeffler)	Albendazole single
Hookworm (Necator, Ancylostoma)	Skin penetration (filariform larvae)	YES	Albendazole single; iron
Strongyloides	Skin penetration (autoinfection)	YES (chronic)	Ivermectin
Trichuris (Whipworm)	Eggs ingested	NO (gut only)	Albendazole × 3 days

238.2.0.2 必背 — Ascaris

• Largest human nematode (15-35 cm)
• Pulmonary phase: Loeffler syndrome (cough + eosinophilia + transient infiltrates)
• Intestinal obstruction in heavy burden (pediatric)
• Biliary migration possible
• Albendazole 400 single dose

238.2.0.3 必背 — Hookworm

• Skin penetration (barefoot)
• Iron deficiency anemia from chronic blood loss
• Loeffler-like pulmonary
• Albendazole + iron repletion
• Cutaneous larva migrans (animal hookworm A. braziliense — beach exposure; ivermectin or albendazole)

238.2.0.4 必背 — Strongyloides

• Skin penetration + autoinfection (chronic for decades)
• Chronic GI + larva currens + eosinophilia
• Hyperinfection in immunocompromise (steroids, transplant, HTLV-1) — 60-85% mortality
• Pre-immunosuppression screening for endemic origin patients
• Ivermectin 200 µg/kg × 1-2 doses (standard)
• Ivermectin daily × 2 wk + albendazole for hyperinfection
• Serology (high sensitivity), Baermann for larvae

238.2.0.5 必背 — Trichuris (Whipworm)

• NO lung migration
• Often asymptomatic
• Heavy: bloody diarrhea + rectal prolapse (pediatric)
• Albendazole × 3 days (less responsive)

238.2.0.6 必背 — Pinworm

• Pediatric perianal itching nocturnal
• Scotch tape test
• Pyrantel pamoate or mebendazole or albendazole single dose
• Treat all household contacts
• Repeat in 2 weeks

238.2.0.7 必背 — Mass Drug Administration (MDA)

• Albendazole 400 mg or Mebendazole 500 mg single dose annually / biannually
• School-age children in endemic
• WHO + partners
• 800+ million pediatric doses/yr

238.2.0.8 必背 — Eosinophilia + Helminth

• Tissue invasion / migration
• Strongyloides essential to screen (chronic, often missed)
• Multiple workup if eosinophilia + travel hx

238.2.0.9 必背 — Lung Migration

• Ascaris, hookworm, Strongyloides (all 3) cause Loeffler syndrome
• Trichuris NOT (no lung migration)

238.2.0.10 必背 — Strongyloides Hyperinfection

• Steroids 重要 cause (corticosteroids, organ transplant)
• HTLV-1 synergistic
• Pre-screening in patients from endemic regions before immunosuppression
• Empirical ivermectin if positive

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