© Springer Nature Switzerland AG 2021
C. S. Foster et al. (eds.)Uveitishttps://doi.org/10.1007/978-3-030-52974-1_52

52. Ascariasis

Artur Filipowicz1  
(1)
Massachusetts Eye Research and Surgery Institution, Waltham, MA, USA
 
Keywords
AscariasisUveitis

Overview

  • Definition

    • Helminthic infection caused by nematode Ascaris lumbricoides

    • Acquired by ingestion of embryonated eggs

    • Larvae pass through pulmonary migration phase for maturation

      • Typically reside in the jejunum

  • Symptoms

    • Often asymptomatic

    • May have redness, irritation, blurring

  • Laterality

    • Unilateral

  • Course

    • Subacute, rare

  • Age of onset

    • Mostly toddlers to adolescents; peak incidence between 2 and 14 years

  • Gender/race

    • No gender or racial predilection

    • More prevalent in crowded rural areas, decreased sanitation

    • Highly endemic in China, India, Southeast Asia, Africa, Latin America

  • Systemic association

    • Pulmonary, intestinal, peritoneal, hepatobiliary, pancreatic ascariasis

    • Infected youth may develop protein deficiency, malnutrition, growth retardation, intestinal obstruction, perforation, or volvulus, reduced cognitive function

Exam: Ocular

Anterior Segment

  • Anterior uveitis

  • Nasolacrimal infestation

Posterior Segment

  • Visceral larva migrans reported, but controversial

Exam: Systemic

  • Often asymptomatic unless heavy wormload

  • Self-limiting pneumonia for 2–3 weeks, occurring 4–16 days after ingesting eggs

    • Sudden onset of significant URI symptoms, fever, cough, wheeze

    • Hemoptysis in severe cases

  • Vague abdominal pain, distention, nausea, occasional diarrhea

  • Peritonitis – may be fatal

  • Hepatobiliary or pancreatic involvement

Imaging

  • n/a

Laboratory and Radiographic Testing

  • Sputum, vomitus, or stool samples show eggs or adult worm

  • CBC with differential – high eosinophilia (>10%) common

  • Radiology

    • Chest – diffuse, mottled pulmonary infiltrate

    • Abdominal with barium contrast – sharply outlined radiolucency

      • Barium inside worm shows filamentous radio-opacity

  • Ultrasound – biliary and pancreatic (4-line sign)

  • ERCP – smooth, linear filling defects

  • Diagnostic vitrectomy (may be therapeutic)

Differential Diagnosis

  • Rare, must have high suspicion

  • Any cause of anterior uveitis

Treatment

  • Pyrantel pamoate 10 mg/kg PO, single dose

    • Contraindicated in hepatic disease, pregnancy

  • Mebendazole 100 mg PO BID × 3 days – treatment of choice

    • Contraindicated in pregnancy

  • Albendazole 400 mg PO, single dose

    • Contraindicated in pregnancy

Referral/Co-management

  • Primary Care

  • Infectious Disease

  • Pulmonology

  • Gastroenterology