Gnathostomiasis Clinical Presentation

Updated: Apr 26, 2018
  • Author: Germaine L Defendi, MD, MS, FAAP; Chief Editor: Russell W Steele, MD  more...
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Patients with gnathostomiasis may complain of mild malaise, fever, urticaria, anorexia, nausea, vomiting, diarrhea, and epigastric pain as the larvae migrate through the gastric and/or intestinal wall. Right upper quadrant pain may accompany the liver-migration phase of the illness. Further symptoms depend on the subsequent larval migration to different parts of the body.

  • Skin and soft tissue - One or more areas involved with tenderness or swelling; creeping eruptions; pain, pruritus, and erythema; nodules or boils

  • Ophthalmologic - Decreased visual acuity, blindness, pain, and/or photophobia [10] due to migration of larvae along optic nerves

  • Otologic - Decreased hearing and/or tinnitus

  • Pulmonary - Cough, chest pain, dyspnea, and/or hemoptysis; coughing up of worm segments

  • GI - May mimic appendicitis, cholecystitis, or an intestinal mass lesion

  • Genitourinary - Hematuria

CNS involvement includes the following: [11, 3]

  • Radiculomyelitis (most common), radiculomyeloencephalitis, encephalitis

  • Low-grade fevers, headache, CNS depression and nonfocal neurologic symptoms

  • Eosinophilic meningitis

  • Subarachnoid hemorrhage

  • Excruciating radicular pain and or headache followed by paralysis, cranial nerve palsies or decreased sensorium over a few days

  • Migration of focal neurologic symptoms (eg, cranial nerve palsies, paralysis of an extremity, urinary retention)



Physical examination findings depend on the area of the body into which the larvae migrate. Single or multiple regions of the body may be involved. The main areas affected are cutaneous, ocular, [12] visceral and neurological.


Skin and soft tissue:

  • Nodular migratory panniculitis (inflammation of the subcutaneous fat), especially of the trunk and upper extremities
  • Nonpitting edematous swelling
  • Creeping eruptions
  • Subcutaneous nodules or abscesses



  • Uveitis (usually anterior)
  • Iritis
  • Intraocular hemorrhage
  • Increased intraocular pressure, glaucoma
  • Retinal scarring/detachment



  • Pleuritic chest pain accompanied by cough
  • Lobar consolidation or collapse
  • Pleural effusions
  • Pneumothorax, hydropneumothorax


  • Tender right upper quadrant, mid-epigastrium, and/or right lower quadrant
  • Right lower quadrant mass
  • Hematuria



  • Fever, stiff neck, and/or photophobia (clinical indicators of meningitis)
  • Clinical signs of increased intracranial pressure
  • Migratory focal neurologic findings
  • Paralysis, cranial nerve involvement, and/or urinary retention


Travel to or from an endemic area

See the list below:

  • Southeast Asia, especially Thailand

  • Japan

  • China

  • Latin America, especially Mexico and Ecuador

  • Western Australia

  • South Central Africa

Dietary/occupational exposure or ingestion

See the list below:

  • Raw or undercooked freshwater fish (ceviche in Mexico and South America, sashimi in Japan, sum-fak in Thailand). Nematode larvae not present in saltwater fish.

  • Other raw or undercooked flesh

  • Contaminated freshwater