Key Difference – Urticaria vs Angioedema
The key difference between urticaria and angioedema is that urticaria or hives are large, raised, pale red patches which occur on the skin as a result of histamine release from the skin blood vessels, commonly due to allergy whereas angioedema is the swelling around the mouth and upper airway which occurs as a result of severe allergic reactions due to complement deficiency. Sometimes both urticaria and angioedema can occur together in the same person.
What is Urticaria?
Urticaria, hives, and wheals refer to the same dermatological manifestation. These are characteristic multiple, large, slightly raised, pale red patches occurring on the skin as a result of skin edema. These are caused by histamine release from the dermal vasculature or skin blood vessels. The commonest cause of this reaction is exposure to an allergen. Pressure, ultraviolet radiation, etc. can also cause urticaria. Usually, they occur very rapidly after the exposure to the causative agent. However, there is a subgroup called chronic urticaria, which occur slowly and has a slightly different pathogenesis. Urticaria is very uncomfortable due to intense itching. Treatment is by removal of the causative agent, antihistamines and steroids. Urticaria responds very well to the treatment. However, they can recur if the person is exposed to the same allergen again. Some people are more prone to get urticarial reaction due to genetic determinants.
What is Angioedema?
Angioedema is a serious allergic reaction which can result in death due to upper airway obstruction. They are usually characterized by inspiratory sound or stridor. Stridor is a sign of imminent airway obstruction. Angioedema refers to the swelling around the mouth and the upper airway including larynx. People with C1 esterase deficiency are prone to get angioedema after exposure to allergens. C1 esterase deficiency is a type of complement deficiency. Compliments are protein involved in allergic reactions. Antihypertensive medicine Losartan is also known to cause this type of reaction. If a person is suspected with angioedema, it is important to protect the airway with endotracheal intubation where a silicon tube is entered into the airway through the larynx to maintain the patency of the airway. They need other supportive treatment such as steroids and antihistamines to control the reaction. Especially, children can die due to sudden airway obstruction caused by this type of reactions. These patients should be handled very carefully as further manipulation by inexperienced people can lead to fatal airway obstructions. The patient should be patiently calmed down first. It is necessary to seek immediate medical attention if a person is suspected with angioedema. Angioedema is usually familial and runs in families. So it is important to be aware of this type of reactions if there is a strong family history.
What is the difference between Urticaria and Angioedema?
Definition of Urticaria and Angioedema:
Urticaria: Urticaria is the occurrence of multiple, large, slightly raised, pale red patches caused by allergic reactions.
Angioedema: The rapid swelling of the dermis, subcutaneous tissue, mucosa and submucosal tissues.
Characteristics of Urticaria and Angioedema:
Urticaria: Urticaria occurs on the skin.
Angioedema: Angioedema occurs around the mouth and the upper airway.
Urticaria: Urticaria is not life-threatening.
Angioedema: Angioedema is life- threatening.
Urticaria: Urticaria occurs due to a histamine-mediated reaction.
Angioedema: Angioedema occurs due to C1 esterase deficiency.
Urticaria: Urticaria is treated with antihistamines and steroids.
Angioedema: Angioedema needs endo-tracheal intubation to protect the upper airway together with other supportive treatment.
Urticaria: Urticaria can occur in any person.
Angioedema: Angioedema usually runs in families.Image Courtesy: “EMminor2010” by James Heilman, MD – Own work.(CC BY-SA 3.0) via Commons “Blausen 0023 Angioedema” by Blausen.com staff. “Blausen gallery 2014“. Wikiversity Journal of Medicine.- Own work. (CC BY 3.0) via Commons