The onset of urticaria is usually not related to the season, so you can get urticaria in winter. The causes of urticaria are complex and usually related to food and food additives, like common animal protein foods, such as fish, shrimp, crab, meat and eggs, as well as food additives, colorings, condiments and preservatives, can cause urticaria to flare up in particular individuals. Also inhalants, such as pollen, animal dander and dust, and formaldehyde, can trigger an attack of urticaria. Various bacterial, viral, and parasitic infections, as well as medications, such as penicillin and sulfonamide, and mechanical stimuli, cold, heat, sunlight, and insect bites, can all trigger an attack of urticaria. There are also psychological factors and endocrine diseases, including chronic medical diseases such as lymphoma, hyperthyroidism, rheumatism, etc., which can lead to the onset of urticaria. Therefore, the occurrence of urticaria is independent of the season and can develop all year round. One suggestion here is that if the urticaria is only mildly itchy, it can be treated with symptomatic oral antihistamines. If the urticaria, in addition to triggering itching, is accompanied by special conditions such as chest tightness and difficulty in breathing, it is recommended to go to a nearby hospital immediately to avoid a more serious allergic state.