An apparent life-threatening event (ALTE) is the sudden appearance of certain alarming symptoms (eg, apnea, change in color or muscle tone, coughing, gagging, choking). The caregiver may fear that the child is dead. It typically occurs in children < 1 yr with peak incidence at 10 to 12 wk. Causes may be digestive, neurologic, respiratory, infectious, cardiac, metabolic, or traumatic (eg, resulting from abuse). Treatment is aimed at specific causes when identified.
An ALTE is not a diagnosis but a group of symptoms that occur acutely in young children.
The most common causes include
Less common causes include
Causes may be genetic or acquired. About 50% of cases are considered idiopathic. If an infant is under the care of one person and has repeated episodes with no clear etiology, child abuse should be considered.
Symptoms and Signs
An ALTE usually is characterized by an unexpected, acute change in an infant's breathing that alarms the parent or caretaker. Features of an event include some or all of the following:
Many infants appear well by the time they present. Ongoing symptoms are concerning but help suggest a cause and guide evaluation.
Evaluation initially involves a thorough history, including
Physical examination is done to check for obvious malformations, neurologic abnormalities (eg, posturing, inappropriate head lag), and signs of infection or trauma (particularly including retinal hemorrhage on funduscopy).
Laboratory and imaging tests (see Table 1: Miscellaneous Disorders in Infants and Children: Diagnostic Tests for Causes of Apparent Life-Threatening Event (ALTE)) are done to check for possible causes. Some are routinely done, and others are done based only on history and physical examination findings, including whether the infant is still symptomatic or has required medical intervention.
Risk factors for child abuse should be sensitively assessed (see Child Maltreatment: Overview of Child Maltreatment). Recurrent ALTEs that are concerning for abuse are those that occur only in the presence of a parent or caretaker but not the hospital staff or when the infant is alone (eg, sleeping while attached to a monitor).
Prognosis depends on the cause of ALTE. For example, risk of death is higher if the cause is a serious neurologic disorder. The relationship of ALTE to SIDS (see Miscellaneous Disorders in Infants and Children: Sudden Infant Death Syndrome (SIDS)) is unclear. About 4 to 10% of infants who die of SIDS have a history of ALTE, and the risk of SIDS is higher if an infant has had 2 or more ALTEs. Also, infants who have had an ALTE share many of the same characteristics with infants who die of SIDS. However, incidence of ALTE, unlike that of SIDS, has not decreased in response to the Back to Sleep campaign.
There seem to be no long-term effects on development.
The cause, if identified, is treated. If the infant required resuscitation or if evaluation detected any abnormalities, the infant is hospitalized for evaluation that includes respiratory and cardiac monitoring and some of the tests listed in Table 1: Miscellaneous Disorders in Infants and Children: Diagnostic Tests for Causes of Apparent Life-Threatening Event (ALTE) as indicated.
Parents and caregivers should be trained in CPR for infants and in safe infant care.
Home monitoring devices may be considered for infants with the following increased risk factors for recurrence:
Monitors should be equipped with event recorders and used for a predetermined period of time. Parents should be taught how to use the monitor and be advised that home monitoring has not been shown to reduce the mortality rate. Also, exposure to tobacco smoke must be eliminated.
Last full review/revision May 2012 by Elizabeth J. Palumbo, MD
Content last modified May 2012