Urticaria is the medical term for hives, an allergic-like reaction of the skin, in which areas of the skin become red, itchy and raised. Here is a quick guide on the basics of hives.
Firstly, it's common to get hives.
Urticaria is the most common cause of skin inflammation. It is estimated to affect around 1 in 30 children, and up to 1 in 5 people throughout a lifetime.
Though distressing, urticaria is generally a benign and self-limiting condition (ASCIA, 2010b).
The science of hives
In response to a trigger, the immune system activates and the cutaneous mast cells release inflammatory mediators such as histamine. Histamine causes the small blood vessels (capillaries) in the superficial layers of skin to leak fluid, and wheal-like swellings to develop on the surface of the skin. The wheals on the skin can be rounded or flat-topped, and vary in size from that of a pinprick to the size of a dinner plate.
They are typically red with a pale centre, and blanch upon applying pressure (ASCIA, 2010a).
Acute vs chronic urticaria
There are two types of urticaria, acute and chronic. Generally, acute urticaria is more common in children and chronic urticaria more common in adults.
Urticaria that usually develops quickly (within minutes) and resolves quickly (within hours or days).
If episodes of urticaria recurrent, but last less than 6 weeks, than the urticaria is acute.
The majority of urticaria presentations are acute.
In the circumstance urticaria does not resolve within 6 weeks, it is classified as chronic.
Not all urticaria is allergy
Though an allergic-like reaction, urticaria can be caused by both allergic and non-allergic mechanisms. Allergic triggers can include
medications (antibiotics, analgesics, anaesthetic muscle relaxants, non-steroidal anti-inflammatory drugs),
Physical contact with an allergen (e.g. animal saliva or dander, plants, raw foods, latex) can also cause urticaria.
Non-allergic triggers can include:
changes in body temperature,
exposure to cold
exercise (ASCIA, 2010b; O’Bingham, 2015).
Often the cause of urticaria is not clear and often we can not find the cause (CIU Chronic Idiopathic Urticaria).
How to treat
The treatment of hives predominantly involves avoidance of the triggers which cause and aggravate urticaria.
Allergy testing may be recommended if an allergic cause is suspected. Anti-histamine medications can be taken to help relieve itching and discomfort. If symptoms do not improve with the administration of anti-inflammatory medications, a short course of oral steroids may be prescribed.
Xolair (Omalizumab) injections can be prescribed privately for Chronic Idiopathic Urticaria.
To discuss with our Allergy Doctors at collective.care Bella Vista please call 1300 344 325.
Australasian Society of Clinical Immunology and Asthma [ASCIA]. 2010a. Urticaria and Angioedema. ASCIA Education Resources (AED) Patient Information. Accessed 3 August, 2015,http://www.allergy.org.au/patients/skin-allergy/urticaria-hives
Australasian Society of Clinical Immunology and Asthma [ASCIA]. 2010b. Urticaria (Hives). Accessed 3 August, 2015, http://www.allergy.org.au/health-professionals/hp-information/asthma-and-allergy/urticaria?highlight=WyJ1cnRpY2FyaWEiLCJoaXZlcyIsInVydGljYXJpYSBoaXZlcyJd
O’Bingham, C. 2015. Patient information: Hives (urticaria). Accessed 4 August, 2015, http://www.uptodate.com/contents/hives-urticaria-beyond-the-basics