hello. welcome to HCM Your daughter seems to have developed an allergic reaction to something which she came in contact with at night. Was this the first such reaction or has she had similar allergies in the past? It is important to find out what caused the allergy, as re-exposure to it will cause the hives and itching again. Was there any contact with dust, pollen, outdoor plants, insects, pets, any possible bed bugs, mites, or new medication? Any history of eating out, especially seafood, nuts,etc? Did anyone else experience similar symptoms? The benadryl can be continued for a few days until the symptoms subside. prednisolone may be needed if there is a severe outbreak of rashes. In case of severe symptoms like breathlesness, puffiness of face, lips, go to the ER immediately. Apply calamine lotion over the itchy skin. These are just temporary symptomatic treatments. To prevent further attacks, the trigger cause needs to be found. If this happens often, keep a note of any possible factors, as I mentioned, that could be the trigger each time. Antihistamine needs to be continued till the symptoms subside completely, maybe 3-5 days. Visit the dermatologist if they are persistent even on treatment. Your doctor may suggest blood tests if needed. Skin tests for allergy are generally not done during an active episode of hives. A later date may be given to you. You may be referred to an allergy specialist. For now, continue treatment as advised and observe. Hope this helps.