ICD-10 defines autism spectrum disorder as

• persistent difficulties with social communication and social interaction, and
• restricted and repetitive patterns of behaviours, activities or interests (this includes sensory behaviour),
• present since early childhood,
• to the extent that these limit and impair everyday functioning

Sensory behaviour may be meltdown or withdrawal or other challenging behaviour when too much information or sensation is experienced.  There can be hyper (or hypo) sensitivity to lighting, problems with depth perception, noises or crowds, smells (or licking), pain, taste/textures.

SIGN guidance is that (145):

• children under 3 with regression in language or social skills should be referred
• not to screen population
• that screening instruments are not 100% reliable but have their uses
• that ASD should be considered in any child with developmental, emotional, psychiatric or behaviour issues, or a genetic syndrome
• in preschool children typical features may be absent
• gender differences are important in terms of symptoms and level of impairment

Assessment

• Lack of shared attention (or late development) eg pointing
• repetitive behaviour/play
• resistance to change
• violent or self injurious behaviour, pica

Types

• Aspergers – social difficulties in absence of learning or communication problems
• Pathological demand avoidance – where underlying problem is high level of anxiety about conforming to social demands or not being in control

Support

ARCH, REACH and National Autistic Society