Pediatric Naegleria Clinical Presentation

Updated: Sep 12, 2016
  • Author: Nicholas John Bennett, MBBCh, PhD, MA(Cantab), FAAP; Chief Editor: Russell W Steele, MD  more...
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N fowleri usually occurs in children or young adults who have a history of exposure to swimming or diving in warm freshwater within the last 7-14 days. Most often, the first symptoms develop 2-5 days after the last exposure to contaminated water. The illness begins suddenly with the abrupt onset of fever, headache, nausea, and vomiting. Occasionally, a prodromal stage of altered taste (ie, ageusia) and smell (ie, parosmia) may occur. Altered mental status occurs in about two thirds of patients and is followed by rapid deterioration to coma and death.



The physical findings in PAM result from rapid spread of N fowleri from the submucosal olfactory nerves through the cribriform plate and into the olfactory bulb. Virtually all patients have meningismus by the time they reach medical care. Patients do not usually develop focal neurologic defects; however, cranial nerve palsies involving III, IV, and V, as well as cerebellar ataxia and reduced deep tendon reflexes, have been reported. Patients often have papilledema and nystagmus. In the final stage just prior to death, the patient may have decerebrate posturing.



PAM is the term applied to the severe hemorrhagic meningoencephalitis caused by pathogenic strains of N fowleri. N fowleri is the only member of genus Naegleria known to be pathogenic to humans.