Parents often ask why their child’s hives have been recurring for weeks or even months. The causes of hives are complex. In addition to the well-known foods, such as fish, shrimp, milk and eggs, which can cause hives, food additives, such as colorings, condiments and preservatives added to food, which we tend to ignore, can also be the cause. Of course, inhalation of pollen, animal dander, dust, fungal spores, formaldehyde, pyrethrum and other inhalants can also cause urticaria. Hot and cold stimuli, sun exposure, insect bites, sweating, and emotional stress can all contribute to hives. Some children develop hives after a cold or fever, or after taking medication, but these children usually get better soon after the fever subsides and the suspected medication is stopped. Because there are many causes of hives and it is difficult to identify them in life, the cause cannot be found in 3/4 of patients. Recurrent attacks of urticaria that occur at least twice a week for more than 6 weeks are called chronic urticaria. In addition to looking for possible causes of chronic urticaria by observing the changes in the rash in relation to the details of life, patients with chronic urticaria can also see their doctor for laboratory screening to help find the cause. What about recurrent hives and how to treat them? Most urticaria is effectively treated with oral antihistamines, and even chronic urticaria often heals after 6 to 12 months. To prevent resistance to the same medication for a long time, you can switch to a different medication. The rash can be controlled by gradually reducing the dosage to stop the drug. In severe urticaria, if it is accompanied by abdominal pain, joint pain and high fever, consider applying hormone therapy for a short period of time, but generally hormone therapy is not recommended.