The symptoms of autism may first appears when the patient is 18~24 months old, but they become more obvious and noticeable during their early childhood (3~6years).
1.Autism Patients’ Social Challenges
Autism patients have social impairments and often lack the intuition about others that many people take for granted. Autistic infants respond less to their own names, show less interest to social stimuli, and barely smile and look at others. As for autistic toddlers, they have less eye contact with people, and unable to express themselves with simple movements or gestures. 3~5 years old Autism patients are less tend to show social understanding and communicate nonverbally, approach others spontaneously, imitate and respond to emotions, and take turns with others. Whereas, they only show intimacy to their primary caregivers.
It's difficult for autistic children to make and maintain friendships. For those who have high-functioning autism, more intense and frequent loneliness will occur even though there's a common belief that children with autism prefer to be alone. The limited data show that, for those who have intellectual disability, autism is often relevant to aggression, destruction of property, and tantrums.
Nearly half of the autistic patients don't have sufficient natural speech ability for their daily communication. Communication difficulties may show up from the first year of life, including delayed onset of babbling, unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the caregiver. In the second and third years, they barely have frequent and diverse babbling, consonants, words, and word combinations; their gestures are more separated from words. They prefer to simply repeat others' works rather than make requests and share experiences.
3. Repetitive behavior
Autistic patients present many different forms of repetitive or restricted behavior, which the Repetitive Behavior Scale-Revised (RBS-R) categorizes as follows.
Stereotypy. Repetitive movement such as hand flapping, head rolling, or body rocking.
Compulsive behavior. Intended and appears to follow certain regulations or rules, such as arranging objects in orders or lines.
Sameness. Refuse to make change, for instance, insisting that something not be moved.
Ritualistic behavior. It involves a constant pattern of daily routines, such as an unchanging menu or a dressing ritual.
Restricted behavior. It means the patient is limited in concentration, interest, or activity, such as preoccupation with a particular TV program, toy or game.
Self-injury. It includes movements that injure or can injure the patient him/herself, such as eye-poking, skin-picking, hand-biting and head-banging.
4. Other symptoms
Some autistic symptoms may be independent of the diagnosis. Many autistic individuals display prodigious skills in perception and attention compare to the general population. More than 90% of autism patients are found that they have sensory abnormalities. Differences are greater for under-responsivity than for over-responsivity or for sensation seeking. 60%–80% of autistic individuals have motor signs that include poor muscle tone, poor motor planning, and toe walking.
About three-quarters of autistic patients face unusual eating behavior. The main problem is selectivity while eating rituals and food refusal also appear. Although there is no enough data to support the theory that autistic children tend to have more or different gastrointestinal symptoms than usual, some do have gastrointestinal symptoms, so the relationship between gastrointestinal problems and autism remains unclear.