T., I have had chronic urticaria (chronic hives) for years now. It really doesn't effect me much anymore...just every now and then (but it used to be daily from mild to severe). My immune system has somehow gotten a handle on whatever it was causing this. After loads of blood work and allergy testing, nothing ever came up. I don't want to discourage you from seeing the Allergist. I would definitely do that, but if nothing comes back, don't quit your search to find out what is going on. You don't say how long this has been going on. Definitely pay attention to any medication/supplements she takes (whether as needed or daily). It could be supplements in foods as well. Antibiotics, etc.? It could very well be a reaction to that (and it can last for a long time!) until the body is completely flushed from it. As for food, she can develop an allergy at anytime (any adult can as well). Try eliminating one thing at a time for at least 2 weeks. Start with the oatmeal and then try all milk products. This is tough, I know (been through it before with my son). Turns out he has a wheat/gluten sensitivity. That's worth trying to eliminate as well. Try to go natural with all of your products (shampoo, body wash, toothpaste, laundry, etc). www.vitacost.com has a great selection and half the price of Whole Foods. Everything we use these days is filled with unnatural chemicals. I was NEVER the "tree hugger" type but I have gone in that direction over the last few years. My entire family is also on probiotics and we eat as many fresh fruits and veggies as possible (very few processed foods). You want to keep her immune system as strong as possible. If it turns out she is diagnosed with "chronic urticaria," don't accept medication as the solution. It's no solution, it just treats the symptoms. Chronic urticaria means chronic hives and they don't know what's causing them. ...but something is indeed causing them. When a child has hives, their immune system is over-reacting to something and you want to get to the bottom of it or their immune system is always compromised. Just know, you are not alone. This is not all that uncommon but it is often really hard to figure out. I have spent years and many hours researching all of this. Hives have been a thorn in our side (at least for myself and my son). For him, I think it has been from medication and gluten. For me, I still don't know after 7 years of this. Oh, one more thing....my gut tells me it's not something topical causing this (like detergents, etc.). It is more likely that it's something she's ingesting. Anything is possible, however.