Autism / Autism Spectrum Support Group
Autism is classified as a neurodevelopmental disorder which manifests itself in markedly abnormal social interaction, communication ability, patterns of interests, and patterns of behavior. Although the specific etiology of autism is unknown, many researchers suspect that autism results from genetically mediated vulnerabilities to environmental triggers.

The shoes. Does he wear lace ups? It is easier to get those tighter. Or stick some extra rip tape on each end of the fastening.
What types of skin sensitivity does he have? Does he actually have dry itchy skin? Is he sensitive to the cold, or to heat? If so, have his thyroid checked, preferably the free T4 and free T3 as well as the TSH, which is typically the one that is first tested.
The guidelines from the leading thyroid associations have recommended in 2012, that the thyroid be checked upon a diagnosis of depression.
Does he eat a well-balanced diet and drink plenty of water? Or is he picky about his food as well?
I agree about taking him to the store. Also, if he can find just one friend who will help him choose clothes that are socially acceptable, it could make a world of difference. Would it help with tightening the shoes if he wore thick socks or more than one pair at once?
Are there any religious or social organizations in your area that can provide a sense of belonging or community?