A 4-year-old boy is brought to the office due to language difficulty and concerns about intellectual development. His parents explain, "He doesn't speak very much and has temper tantrums almost every day." They describe the patient as a slow learner who uses only single words and frequently mumbles. He is happy to play alone with cars for long periods but will scream uncontrollably when his parents take them away. The patient can recognize a circle and the colors yellow and red but struggles to name other shapes and colors. He crawled at 7 months and walked by 13 months. The patient briefly attended preschool but would become hyperactive and repeatedly bite his hands when others tried to engage him. He was born at term from an uncomplicated pregnancy and delivery, and his physical growth has been normal. Weight and height are at the 50th percentile. During examination, the patient sits in the corner lining up cars. When his mother attempts to divert his attention, he has a temper tantrum and begins to bite his hand. A brief physical examination is normal. Which of the following is the most likely explanation for this patient's behavior?
Autism spectrum disorder | |
Clinical features |
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Assessment & management principles |
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This patient's preference for solitary play, repetitive stereotypical movements (eg, hand-biting), and fixated interest in cars are suggestive of autism spectrum disorder (ASD). ASD is 4 times more common in male individuals and symptoms become apparent in early childhood.
By age 4 children should engage with others in imaginative as well as reciprocal play using a variety of toys, rather than the solitary and repetitive play with intense fixated interests (eg, playing with cars for long periods, lining up cars) seen in this patient. When children are diverted from their preferred activity or when their routine is changed, it can result in distress and present as temper tantrums. Stereotypical or repetitive movements, such as head-banging or hand-biting, are often used to self-soothe in patients with ASD. Language impairment in ASD (eg, only using single words at age 4) is variable and can range from subtle abnormalities of pitch and odd word choice to absence of functional speech.
(Choice B) Language disorder (ie, deficits in comprehension or production) can be difficult to diagnose due to variability in language acquisition before age 4. However, nonverbal communication (eg, eye contact, sharing of interests) should be normal. This patient's lack of developmentally appropriate engagement with others and his restricted interests are more consistent with ASD.
(Choice C) In disruptive mood dysregulation disorder (DMDD), recurrent developmentally inappropriate temper tantrums occur. Diagnosis should not be made prior to age 6, and the outbursts should not be better explained by another disorder, such as ASD. DMDD would not explain a preference for solitary play and restricted interests.
(Choice D) ASD may present with speech delay as well as intellectual disability. Isolated intellectual disability (ID), however, would not explain a lack of social responsiveness. Children with ID still try to communicate, nonverbally when necessary, and engage in play with others. Diagnosis of ID requires standardized testing and is not given to patients age <5.
(Choice E) Although this patient engages in hand-biting, he does not display other characteristic features typical of Lesch-Nyhan syndrome, including motor dysfunction (eg, dystonia, spasticity, writhing movements), nephrolithiasis, or gout.
Educational objective:
Preference for solitary play, restricted interests, and repetitive behaviors are suggestive of autism spectrum disorder. Variable degrees of language and intellectual impairment may be present.