2. Infection
Such as bacterial infections like dental caries, tonsillitis, otitis media, fungal infections, viral infections like hepatitis B, parasitic infections like intestinal roundworms, pinworms, etc., can induce this disease by altering the body's reactivity.
3. Physical Factors
Such as cold and heat stimuli, sun exposure, friction, etc., can all trigger this disease, but the types of onset are different, such as cold-induced urticaria, sunlight-induced solar urticaria, friction-induced dermatographic urticaria, etc.
