Q. My 12-year-old son suffers from sinusitis and allergies to pollen, grass and fabric softener. He had boiled eggs for lunch today and 15 minutes later had hives over his entire body, including his genitals and the bottoms of his feet, and his lips and eyes swelled up. The hives only seem to last a few hours, but they itch and seem to spread. I took him to the clinic immediately after school, where he was prescribed Allergex and Paracetamol. He has been eating eggs all his life and has never had any reaction to them before. What can we do to ease the itching of his hives? Should he avoid eggs in the future?
A. It's good that you took your son to be evaluated immediately and that he is improving.
Your son’s hives and swelling are also called urticaria and angioedema. Hives are itchy pink or pale swellings that appear as welts, and can occur on any part of the skin. Each individual hive typically lasts minutes to hours before fading away without leaving a mark. New hives can arise as old ones fade away. They can vary in size from a few millimeters to inches, and can blend together to form larger swellings.
Hives result from blood plasma leaking through small gaps between the cells lining small blood vessels in the skin. Histamine is a natural chemical released from allergy cells, which lie along the blood vessels in the skin. Histamine causes the itching, swelling, and red color of hives. The angioedema, or swelling of the deeper layer of skin, occurs through a similar mechanism. With generalized urticaria and angioedema, topical treatments do not tend to improve symptoms; oral antihistamines are frequently needed.
Food allergy is one of the most common causes of acute hives. Egg are a very common food allergen for children.
Your son should be evaluated by his allergist for his recent symptoms. In his case, the cause of his reaction may have been the egg ingestion, or another ingestion that he may not have recalled immediately. Insect stings and medications are other common triggers for acute urticaria and angioedema.
Your allergist will likely perform testing, which could include skin prick testing and/or blood testing to various suspected allergens. Once the allergen is identified, your allergist will help you decide what avoidance measures to take.
Because you suspect egg, avoidance of egg until your son sees his allergist would be a safe and conservative strategy.