My Son Takes Proventil For Asthma. He Uses For Excresing

my son takes proventil for asthma. he uses for excresing induced asthma. Last night he said that his corners of his mouth on the inside and outside felt really weird. he described the best he could as being rubbery. Maybe that might make sense to you. It was the only was he could describe it. Could this be aside affect by taking the inhaler. He has been taking for about a month one and half months now. Thank you