When it comes to being an autistic teen to adult, I've heard hygiene become a significant complaint. For that matter I've met several teens with autism who need more practice. Why does this happen?
Hygiene of this kind has to be ingrained in routine (note that word!) at early teen years. Remember with autism it's ROUTINE, ROUTINE, ROUTINE. Since this is a change and a big change, don't expect this to go easily. Expect it to be a pain in the neck instead. Here's an approach I suggest.
Give details. We work best with details on anything. Explain to your child how they're body is changing at this special time in their lives. They're body is going to start creating odors through sweat that others will find offensive. Explain how those odors will affect other people. Use this to show how important it is to be clean.
Taking baths is taught from early childhood and my son loves his bathes (lucky me!) but I still have trouble getting him to move that washcloth over his body. He has this idea that sitting in the water is enough. It's going to take applied practice to fix this routine because he's old enough that I won't do it for him anymore.
The biggest changes are use of things like deodorant. This can get tricky because of our sensory issues. Think about this; some deodorants can irritate our skin or leave a residue that we can feel like sticky syrup under our armpits. Then there's the smell. We may not care for the odors that the perfume creates. So you really can't just go out and grab one off the store shelf and expect us to use it. My suggestion? Get your child involved in choosing their deodorant. Again, apply details as to why it's important.
Consider this for the kind of soap, toothpaste and shampoos you expect him or her to use too. Sensory issues change with age and will affect all these areas. Changes in hormones also affect sensory issues so be prepared for that idea too. Hopefully this blog gives you some food for thought on hygiene in our teens with autism. If it's not made a routine, it won't happen and will carry into adulthood. Yes, there will be resistance. Make sure they understand, no matter how busy life gets, they must always take time for their hygiene.