Best Next Step: Autism Screening
The best next appropriate step is to screen for autism using a validated autism-specific screening tool such as the M-CHAT (Modified Checklist for Autism in Toddlers), as this 24-month-old presents with classic red flags including failure to respond to name, lack of eye contact, and repetitive behaviors (lining up toys). 1, 2
Clinical Reasoning
This child demonstrates the hallmark triad of autism spectrum disorder (ASD) features at the optimal screening age:
- Failure to respond to name at 12 months is highly specific (86%) for developmental abnormality including ASD 1, and persistence at 24 months is even more concerning 1
- Lack of eye contact represents impaired social-emotional reciprocity, a core diagnostic feature 2
- Repetitive behaviors (lining up toys) indicate restricted/repetitive patterns, completing the diagnostic triad 1, 2
Why Autism Screening First
Autism-specific screening should precede hearing testing in this clinical scenario because:
- The constellation of symptoms (social communication deficits PLUS repetitive behaviors) is pathognomonic for ASD rather than isolated hearing loss 2, 3
- Children with pure hearing loss typically compensate with enhanced visual attention and social engagement, which this child lacks 1
- Administering screening tools during 18-24 month well-child visits improves early identification of autism, with diagnosis stability confirmed at these ages 4
Recommended Screening Approach
Use the M-CHAT as the primary screening instrument because:
- M-CHAT has superior sensitivity and specificity compared to CHAT and is preferable for developmental surveillance 4
- It is validated specifically for 18-24 month-olds 4, 5
- The tool captures both social communication deficits and restricted/repetitive behaviors 6
Critical Timing Considerations
Screening at 24 months is optimal because:
- Characteristic autism behaviors should be evident in simple forms before 18 months, while 24-month screening identifies children with regression 4
- Early identification is critical as earlier detection and provision of services improve long-term prognosis 2
- Developmental trajectories showing declining social communication behaviors between 12-24 months are highly predictive of ASD 1
Common Pitfall to Avoid
Do not delay autism screening to first rule out hearing loss 2. While hearing assessment will ultimately be needed as part of comprehensive evaluation, the clinical presentation strongly suggests ASD, and:
- Clinicians should not dismiss social concerns because other developmental domains appear intact 2
- Children with ASD may have normal language and cognitive skills while demonstrating profound social impairments 2
- Delaying autism-specific screening postpones access to early intensive behavioral interventions 7, 3
Subsequent Steps After Positive Screen
Following a positive autism screen:
- Refer for comprehensive diagnostic assessment using ADOS (Autism Diagnostic Observation Schedule) and clinical evaluation based on DSM criteria 1
- Arrange hearing evaluation as part of comprehensive workup (not as initial step) 1
- Initiate early intervention services immediately without waiting for definitive diagnosis 7, 3
- Refer to multidisciplinary team including developmental pediatrician, psychologist, and speech-language pathologist 7