Synopsis
Recognise diverse and masked autistic presentations, refer on clinical concern without misusing screening scores, complete multidisciplinary diagnostic and coexisting-needs assessment, and provide strengths-based support before and after diagnosis.
- Autism is a lifelong neurodevelopmental difference characterised by persistent social-communication differences plus restricted or repetitive patterns, interests or sensory responses with functional impact.
- Presentation varies by age, language, intellectual ability, sex, culture and environment; masking can delay recognition, especially in girls and adolescents.
- Take child, parent and professional concerns seriously even when different settings report different behaviour.
- Look for patterns across reciprocity, gesture and joint attention, relationships and communication alongside flexibility, repetitive movement, intense interests, routines and sensory processing.
- Do not use poor eye contact, a single repetitive behaviour or late speech alone as diagnostic shorthand.
- An autism likelihood questionnaire can organise evidence but is neither required nor diagnostic; a negative result does not rule out referral.
- Reference-standard practice is a multidisciplinary clinical diagnostic assessment integrating developmental history, observation, ICD-11 or DSM-5 features, examination, differential diagnoses and coexisting needs.
- Assess hearing, vision, language, cognition, adaptive function, mental health, ADHD, epilepsy, sleep, feeding, continence and physical pain as indicated.
- NICE advises no routine medical investigations solely for autism; consider genomic testing for dysmorphism, congenital anomalies or intellectual disability and EEG only if epilepsy is suspected.
- Provide reasonable adjustments and needs-based education, communication and sensory support while the diagnostic assessment is pending.
- For core social-communication needs, NICE supports a specific play-based social-communication intervention with parent, carer, teacher or peer mediation according to age.
- Do not use antipsychotics, antidepressants, anticonvulsants or exclusion diets for core autism features; treat coexisting conditions and functionally assess behaviour that challenges.
Key red flags
Language or social regression under age 3 requires autism-team referral; language regression after 3 and motor regression at any age first requires paediatric or neurological assessment.
New seizures, focal neurology, loss of mobility, catatonic slowing, dehydration or severe self-injury indicates an acute coexisting problem.
Dysmorphism, congenital anomalies, microcephaly or macrocephaly, intellectual disability or epilepsy can indicate a coexisting genomic or neurological disorder.
Bruising, sexualised behaviour, abrupt fear, exploitation, restraint injury or unexplained change must trigger safeguarding assessment; communication difficulty increases vulnerability.
Restricted diet with weight loss, nutritional deficiency, choking, constipation or pica needs medical and dietetic assessment rather than being accepted as an autism trait.
Girls, intellectually able young people and children in highly structured environments may mask or compensate, so apparently typical eye contact or vocabulary cannot exclude autism.
Investigation priorities
Integrate development, direct observation, diagnostic features, function, differentials and coexisting needs.
Establish early features, persistence, masking, strengths and impact across home, education and community.
Management branches
Development, behaviour, communication or wellbeing raises possible autism.
- Hear child and caregiver concerns and gather examples of reciprocity, communication, flexibility, interests and sensory response.
- Review development, function and masking across settings and assess hearing, language, cognition and coexisting conditions.
- Refer to the autism team on clinical concern even when a likelihood tool is negative or one setting reports fewer features.