Why Does Allergy Cause Swelling?
Disease description:
My younger brother is 30 years old this year. Recently, he developed a rash on his face—red, swollen, and itchy—and it has gradually spread and worsened. After seeking medical evaluation, the doctor diagnosed it as an allergic reaction. He would like to know: Why does an allergic reaction cause swelling?
Doctor's answer (1)
Dr. Huang Lingjuan
Allergic reactions can cause tissue edema, primarily associated with allergic responses affecting the skin and mucous membranes. During an allergic reaction, capillary permeability increases, leading to leakage of plasma proteins and a consequent decrease in plasma colloid osmotic pressure. This results in accumulation of interstitial fluid and may lead to allergic edema. To confirm whether tissue edema is caused by allergy, it is recommended to identify and avoid the allergen, promptly undergo relevant diagnostic tests at a hospital, and follow your physician’s guidance for anti-allergic, anti-inflammatory, and anti-edematous medications—these interventions help alleviate symptoms. If you experience frequent allergic reactions, allergen testing is advisable. Desensitization therapy, as directed by your physician, can effectively reduce the frequency of allergic episodes. Additionally, increasing physical activity on weekdays can help strengthen your overall constitution.
