Depending on the duration of the Hives (urticaria) they are usually classified as either acute of chronic:

Acute Urticaria (lasts for less than 6 weeks):

• Viral Infection
• Bacterial Infection
• Food Allergy
• Drug Allergy
• Food additives or preservatives
• Insect stings

Chronic Urticaria (lasts for more than 6 weeks):

• Chronic Infection
• Physical triggers such as pressure, heat, sunlight, sweat, cold and water
• Autoimmune conditions such as thyroid or connective tissue condition
• Due to a disease which arises spontaneously

Usually a cause is never found.  So called cases of ‘idiopathic urticaria’ make up more than half of all who suffer with chronic urticaria.

Treatment At The Skin Hospital

All dermatologists at the Skin Hospital are highly trained to treat this condition. Your specialist will ask you detailed questions to understand whether there are any obvious triggers for your hives. Often no tests are needed to confirm the diagnosis. Blood tests may sometimes be needed to look for underlying causes and to distinguish urticaria from other conditions (especially if wheals are present for over 24 hours at a time). A skin biopsy is not normally needed, but may be requested to rule out other causes.

General measures

• If a trigger is found, avoidance of the trigger is helpful. Drugs such as aspirin, non-steroidal anti-inflammatories (NSAID, e.g. ibuprofen) and opiates (e.g. morphine, codeine) can worsen or cause urticaria, so should be avoided if possible.

Oral treatments

• Oral treatment focuses on taking non-sedating anti-histamine tablets. These need to be taken regularly for the greatest benefit. The specialist will recommend an appropriate dose.
• In severe cases that do not respond to an adequate dose of anti-histamines, other medications can be tried. Oral steroids can be taken for short-term use only.

Other systemic treatments

• The injectable biologic medication Omalizumab is newly available to treat this condition. Such medications should only be used under the direct supervision of a specialist.

These medications do not cure urticaria, but can suppress the symptoms effectively. Hives are  not predictable and can resolve spontaneously.

Further Information

If you would like further information on hives the below sites provides more in-depth descriptions of hives:

Urticaria (Hives) – ACD 

Urticaria Overview – DermNet NZ