Can Babies Develop Allergies At 8 Months? Specifically To Milk

Can babies develop allergies at 8 months? Specifically to milk or fruit. She has been on Enfamil Gentle ease for 6 months, originally she was on soy because of reflux but I didnt think it was a big enough different to keep her on it. I have noticed before that her cheeks get flushed, but thought it was because of teething. Monday she developed a rash all over (with eczema like spots on her back) after she had yogurt and a jar of fruit. She has been having bag gas pains at night also recently, I dont know if that is related. But her breathing is good. I dont know if I should get her tested for allergies or not.