Hi Janelle! Welcome. 😀 Hopefully we can be a helpful resource for you. I am not an asthma expert, so all I can really offer you is speculation, but thumb sucking and asthma aren't connected as far as I'm aware. Suckling is an instinctual reflex all newborns have, and some kids continue with thumb sucking as they get older because it's a source of comfort. I am curious to see if one of our asthma educators, has input on this, as she has several children and has written about her experience as an asthma parent quite a bit.
One thing I want to check on, though -- have you been advised to wean the inhaler by his doctor? It's always important to take steps like that with the approval and supervision of his healthcare team.
Looking forward to seeing you around! -Melissa, asthma.net moderator