Hi K.,
When I worked in a special needs preschool, the Director of our Bridges Program wore an excessive amount of VERY strong perfume (can you imagine?). I had to work next to her in a tiny 10 x10 room, as well as DOZENS of children with SPD, Autism, Asperger's, etc. No one said ANYTHING to her as she was the daughter of our Director. One of the MANY reasons I don't work there anymore!
Anyway, there are in fact MANY things your teacher can do. I guess if I were her the first thing I'd do is in the weekly or monthly newsletter to parents I would include a paragraph about it in a generic way of course, maybe pull a study off the internet about how strong scents effect children's learning, allergies, asthma, SPD, etc....perhaps she's already done this and gotten no response.
I think maybe what happens is the offending child maybe getting ready for school while Dad's getting ready for work, maybe Dad splashes some on himself, some on his son! Just like Daddy! Everyone in the family is so used to the scent they likely don't realize how strong it smells to everyone else.
I think if you very humbly and apologetically approach his mom privately....I say that because if another mom approached ME in that way, I would probably be grateful....although I guess being defensive is a natural reaction...
Yeah, you can approach an administrator in the same manner. That's probably the safest route.
Good Luck, I feel for you (and all the kids in the class)!