Hi one of my cats has allergys and in 5 years they still dont know whats causing it, i take her every few mths for an injection and that clears it for a while i have her only on pure food no additives like natures menu and applaws but she still loses hair and gets sore spots around her neck that need vet treatment, they say it could be a dust allergy and nothing they can do about that , they have been giving her steroids but the vet wouldnt give them to her this time as she dosent agree with keep giving them so she just had antibiotics injection , the trouble is she scratches and then the tiny spot turns into a big sore so im back to vet again and this goes on continously, hope you get better results with your baby.