A mother runs into the pediatrics emergency department, clutching her 10 month old daughter.  She states her daughter had been drinking from her bottle at home and then stopped drinking, turned purple, and became limp for ten seconds, and then started crying.  Her daughter is still crying now, moving around in her mother’s arms.  Vital signs are normal for the patient’s age, and her fingerstick is 92.  What diagnosis/diagnoses would you consider for this patient, and what further work-up should be initiated?

This patient had what is referred to as an ALTE, an apparent lift-threatening event, defined as an episode that is frightening to the observer which is associated with some combination of color change, apnea, choking/gagging, or change in muscle tone.  ALTE accounts for 0.6-0.8% of pediatric ED visits in patients less than one year of age, and are most common in that age group (i.e. < 1 year of age).

Children are at increased risk for ALTE if they have a prior history of feeding issues (rapid feeding, choking during feeding), apnea, or cyanosis.

There are a variety of etiologies to consider as potential causes of an ALTE:

– CNS disorder (seizure, meningitis/encephalitis, etc)

– Cardiovascular disorder (i.e. long QTc syndrome, myocarditis, etc.)

– Infection (i.e. urinary tract infection)

– GI disorder (GERD, intussusception) – second most common

– Respiratory disorder, especially infection, also breath holding spells

– Overdose/toxin exposure

– Metabolic disorder (i.e. inborn error of metabolism)

– ENT pathology (i.e. foreign body, vocal cord abnormalities, etc.)

– Unknown etiology – most common

– Child abuse

Studies recommend that the vast majority of patients who experience ALTE should be observed/admitted with telemetry monitoring for at least 24 hours. Recommended serum investigations include CBC, basic metabolic panel, magnesium, phosphorous, blood gas, ammonia, lactate, and pyruvate.  Also, urinanalysis, urine culture, CXR, and blood culture should be obtained to assess for an infectious etiology.  A urine toxicology screen should be sent.  An EKG should be performed as well as an EEG.

Outcomes in children with ALTEs depends on the etiology of the ALTE itself.  In the case of ALTEs, save for those that signaled serious underlying conditions (i.e. seizure disorder, arrhythmia), studies have not demonstrated long term developmental deficits in these patients.


Hall K L, Zalman B, Evaluation and Management of Apparent Life-Threatening Events in Children, Am Fam Physician, 71(12): 2301-2308, 2005.

Kiechl-Kohlendorfer U, Hof D, Pupp Peglow U, Traweger-Ravanelli B, Kiechl S, Acute Pediatrics: Epidemiology of Apparent Life Threatening Events, Arch Dis Child, 90: 297-300, 2005.

McGovern M C, Smith M B H, Acute Pediatrics: Causes of Apparent Life Threatening Events in Infants: A Systemic Review, Arch Dis Child, 89: 1043-1048, 2004.

June 2024