Hi Fawzeia. It sounds like you are having an allergic reaction to the Botox. We have seen this twice before in our practice. One patient developed a resistance to Botox and each time we injected, she reacted by developing hives at the injection site. The hives did last more than 24 hour...
Perhaps the BOTOX® relaxed your muscles unequally and/or relaxed non-target muscles.
For example, if some of the BOTOX® diffused into the depressor labii [the muscles which pull the lower lip down] then when you smile with your mouth open the lower lip might not come down as much as...