Allergy skin tests and injections. Hives may be the first sign of life-threatening anaphylaxis. If so, it will be followed by itching, runny nose, wheezing, paleness, cold sweats and low blood pressure. Without prompt treatment, coma and cardiac arrest can occur. If a medication or acute viral infection is responsible, hives usually disappear within hours or days.
Some cases become chronic and last for months or years.
Don't wear tight underwear or foundation garments. Any skin irritation may trigger new outbreaks. Don't take hot baths or showers. Antihistamines, ephedrine, terbutaline or cortisone drugs to relieve itching and rash. Sedatives or tranquilizers for anxiety.