Urticaria is not chicken pox. It is caused by allergies and is mainly characterized by the appearance of erythema, a rash of light red or pale white color around the body. The rash can come and go within 24 hours, and is mainly itchy. In severe cases, it can be accompanied by joint pain, abdominal pain, stomach pain, and even chest tightness, breathlessness, and difficulty breathing. Chickenpox is caused by the varicella-zoster virus infection. The first and most common symptom of chickenpox is fever, followed by erythema, blisters and crusts on the skin. The rash of chickenpox does not come and go within 24 hours like hives. The treatment of hives is based on anti-allergy treatment, while chickenpox is based on anti-viral treatment.