I just found out that my cat had some kind of allergy and well she had an itchy lesion on her head, the vet said it wasn't anything serious and that all I had to do was put an ointment on her wound. Almost a week later she is now sneezing uncontrollably and I am really worried that this could be a sighn of something serious. She is still active and seems to be happy but the poor thing sneezes all the time. Should I take her back to the vet? What is wrong with her?