In addition, there is inducible or physical urticaria, in which the hives are triggered by a specific external stimulus, such as:
Dermographism: The appearance of hives when scratching or rubbing the skin.
Cold Urticaria: Triggered by exposure to cold.
Pressure Urticaria: Caused by sustained pressure on the skin (e.g., by tight clothing).
Solar Urticaria: Induced by exposure to sunlight.
Cholinergic Urticaria: Related to an increase in body temperature, such as during exercise or a hot bath.
Common Causes of Urticaria
The range of possible triggers for acute urticaria is wide:
Allergic Reactions: To foods (such as shellfish, nuts, eggs, and milk), medications (antibiotics, pain relievers such as aspirin or ibuprofen), insect bites, or latex.
Infections: Both viral (such as the common cold or hepatitis) and bacterial (strep throat).
Physical Factors: As mentioned for inducible urticaria.
Emotional Stress: Although not a direct cause, it can exacerbate outbreaks in susceptible individuals.
