Posted on 20 August 2013

Dr Karen Ordemann, a dermatologist from Mediclinic Milnerton sees cases of hives – or urticaria – frequently. Approximately 20% of people will experience urticaria in their lifetime. 

I have itchy blotches all over my body, but how do I know they’re hives?
Urticaria is a common skin reaction that presents with ‘wheals’ or ‘hives’. These are itchy, pink swellings that usually get worse, fast. Usually, an individual hive doesn’t last longer than 24 hours and leaves the skin with a normal appearance, but the whole attack usually lasts much longer. They occur anywhere on the body, including the palms and soles, and vary in size and number, ranging from a few millimeters to large areas and of varying shapes. Sometimes hives can actually cause an area of the body to swell – this is called angioedema where the deeper body tissue is affected, like an eyelid or lip, for example.

What causes hives?
There are two main types of urticaria and it can happen to anyone regardless of gender, age or race. When hives are present for less than six weeks, it’s called acute urticaria and you’ll probably be able to identify a cause. If the hives continue on most days for longer than six weeks, that’s called chronic urticaria, which is less common and a cause can only be found in about two-thirds of cases. Causes for acute urticaria include associated viral infections (this is a cause in 40% of cases), or may be an allergic reaction to medicine like penicillin or injections, or a food allergy such as nuts. In one-third of patients with chronic urticaria, the cause is usually a physical factor, like heat, cold, vibration or pressure. In other cases, it’s an autoimmune response, fighting an allergen made by the patient’s own body. Other possible causes may include an abnormal thyroid or parasite infestations like tapeworm, and will need to be excluded.

If you see that you’ve broken out in hives, what’s the standard treatment?
Most cases can be treated with antihistamines. If the patient has other symptoms with the urticaria, such as vomiting, diarrhea, dizziness, swelling of the mouth or throat, or difficulty with breathing, the patient needs to be seen by a doctor or clinic immediately. Some doctors will also recommend using calamine lotion to soothe the skin.

How do sufferers of urticaria manage their condition long-term?
In patients who developed acute urticaria in response to a certain medication, injection or foodstuff, the patient should avoid that specific medication or food as it will most likely cause the hives to recur. In patients with chronic urticaria, even when the cause is found, it’s unlikely that it can be avoided altogether – such as cases that occur due to heat or cold – so the condition will often be managed with long-term antihistamines or other immune modulating medication. Although chronic urticaria is not always curable, it’s usually manageable with medication.

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Published in Dermatology

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