Etiology
Allergic reactions
: Foods (nuts, shellfish), medications (antibiotics, NSAIDs), insect bites or stings.
Physical triggers
: Heat, cold, sunlight, pressure on the skin, or exercise.
Infections
: Viral or bacterial infections can trigger hives.
Stress
: Emotional stress can exacerbate symptoms.
Idiopathic
: Often, the cause cannot be identified, especially in chronic urticaria.