Autism is a developmental disorder that affects the way a child interacts with others and his surroundings. Symptoms can appear in infancy and range from mild to severe. Although diagnosis usually does not occur until around the age of 3, early intervention can make a substantial difference in helping an autistic child overcome future obstacles.
Abnormal Sensory Reactions
The parents of children later diagnosed with autism often report that their children had abnormal reactions to external stimuli during infancy, according to Health Communities. Some children overreact to bright lights, loud sounds and strong smells, whereas others underreact or appear not to see or hear them at all.
Missed Communication Milestones
Autistic infants often fail to hit normal milestones for communication and social skill development. Pre-language skills such as making sounds and babbling can be delayed or absent, as can facial expressions that constitute common two-way communication between babies and caretakers.
Autism Speaks instructs parents to have their child evaluated if the child cannot smile or show happiness by the age of 6 months and does not use facial expressions to banter back and forth by 9 months.
Behavioral Signs
Babies generally thrive on structure and routine, but many infants later diagnosed with autism exhibit extreme and inflexible resistance to change, according to Help Guide. Furthermore, many forego a favorite stuffed animal in favor of an almost obsessive attachment to unusual objects.
Repetitive head banging, scratching or hitting while in the stroller or crib is another common sign of autism, according to the National Autistic Society. The society points out that children without autism also sometimes exhibit these behaviors, so parents should share any concerns with a pediatrician.
