Papular urticaria, also known as insect bite dermatitis, is a different disease from urticaria. Urticaria, also known as wheals, is called yinzhen in traditional Chinese medicine, and it is a localized edema of the skin and mucous membranes due to temporary increased vascular permeability. For most patients with urticaria, the exact cause cannot be identified. Common causes include foods, such as animal proteins and certain food additives that induce urticaria. Urticaria can also be triggered by certain infections as allergens, as well as by certain medications such as penicillin, serum products, various vaccines, sulfonamides, etc. Additionally, common inhalants such as pollen, animal dander, dust, fungal spores, dust mites, and volatile chemicals can also trigger urticaria. Papular urticaria is characterized by a small blister in the center of a reddish area, often resulting from bites or stings of various insects like mosquitoes, mites, bees, etc., or from irritation by toxic sap on the skin. Improvement can be seen once removed from the allergenic environment.