What are the causes of excessive drooling (sialorrhea) in a 20‑month‑old child who is not teething?

Excessive Drooling in a 20-Month-Old (Non-Teething)

Constant drooling at 20 months of age, when teething is not the cause, is developmentally normal and requires only reassurance and observation, as drooling is not considered pathological until after 4 years of age. 1, 2, 3

Developmental Context

• Drooling is physiologically normal in children under 2 years of age and does not warrant concern or intervention at 20 months. 4
• The developmental milestone for saliva control typically occurs between ages 2-4 years, with drooling considered neurodevelopmentally abnormal only if it persists beyond 4 years of age in the awake state. 1, 2, 3
• At 20 months, the child is still within the expected developmental window for acquiring mature oral-motor control and oral sensation needed for saliva management. 1

Common Physiologic Causes at This Age

The most common reasons for drooling in developmentally normal toddlers include:

• Poor oral-motor control - the muscles and coordination required for swallowing saliva are still maturing. 1
• Impaired oral sensation - the sensory awareness needed to trigger swallowing reflexes is still developing. 1, 3
• Postural factors - head-down postures during play and exploration are common at this age and promote saliva spillage. 2
• Behavioral factors - sucking on fingers, toys, or clothing increases saliva production and spillage. 2

Red Flags Requiring Evaluation

While drooling at 20 months is typically benign, certain features should prompt neurologic assessment:

• Motor developmental delays - inability to sit independently, walk, or achieve age-appropriate gross motor milestones. 5
• Facial or oral motor weakness - poor weight gain, feeding difficulties, weak cry, or asymmetric facial expressions suggest cranial nerve or neuromuscular pathology. 5
• Regression of previously acquired skills - loss of motor abilities the child previously demonstrated. 5
• Asymmetric motor development - development of handedness before 18 months, asymmetric grasp, or asymmetric movement patterns. 5
• Persistent primitive reflexes or absent protective reflexes - these indicate neuromotor dysfunction. 5

When Drooling Becomes Pathological

• After age 4 years, persistent drooling in the awake state is considered abnormal and warrants investigation for neurodevelopmental conditions such as cerebral palsy (where drooling occurs in 10-58% of cases), intellectual disability, or other conditions affecting oral-motor control. 2, 3, 6
• Delayed saliva acquisition may be an early indicator of developmental or intellectual delay, though this typically becomes apparent after age 2-4 years, not at 20 months. 1

Management at 20 Months

For a developmentally normal 20-month-old, no active intervention is needed:

• Reassurance is the primary management strategy, as this is a self-limiting developmental phase. 1, 4
• Parents should be counseled that drooling will naturally resolve as oral-motor skills mature over the next 1-2 years. 1
• Observation for developmental milestones should continue at routine well-child visits, with particular attention to motor development, speech acquisition, and feeding skills. 5

Common Pitfall

The most important pitfall is over-investigating or treating normal developmental drooling in children under 4 years of age. Unless accompanied by motor delays, feeding difficulties, or other neurologic signs, drooling at 20 months requires only watchful waiting. 1, 4