Treatment

• ​Even without treatment, most cases of acute hives and angioedema will resolve spontaneously within hours.
• Avoiding the allergens, if any, is the first step.
• A special preservative-free diet is advisable.  It is also helpful to avoid stress, and fatigue.
• Try to keep the air around you cool and comfortable. Avoid tight or restrictive clothes, as well as long periods of sitting or walking.
• There are also certain medications that may worsen chronic urticaria/angioedema rather than help. Hence, it is best to avoid medicines such as angiotensin converting enzyme (ACE) inhibitors, aspirin and non-steroidal anti-inflammatory drugs (NSAIDs).
• If the hives or angioedema are in fact part of an anaphylactic reaction, then you may be in urgent need of an epinephrine injection.
• H1 antihistamines can be prescribed by your doctor that will block the effect of histamine in your body.

H1 Antihistamines

H1 antihistamines are a common treatment for both urticarial and angioedema.

1st generation H1 antihistamines:

• Diphenhydramine
• Chlorpheniramine
• Hydroxyzine

2nd generation H1 antihistamines:

• Cetirizine
• Loratadine

3rd generation H1 antihistamines:

• Levocetirizine
• Desloratadine
• Fexofenadine

Using H1 Antihistamines

The 2nd generation drugs are preferred as first line therapy due to less side effects (sedation, dry mouth, blurred vision, constipation, urine retention), and they stay in the body for a longer time, which allows for less daily dosing. Continuous use on a daily basis is found to be superior to taking them ‘as needed’, as they prevent the development of the swelling rather than treat already existing one.

The newer 2nd generation H1 antihistamines or what are known as the “3rd generation H1 antihistamines”. They are safer and do not cause heart problems.

If there is no improvement of the symptoms after two weeks of initiation of 2nd generation antihistamine, the doctor may increase the dose of the drug. The dose can be increased up to fourfold of the recommended dose to achieve symptomatic control. Another option is adding a second 1st generation antihistamine or adding an H2 antihistamine.

• H2 antihistamines:
• Cimetidine
• Ranitidine

The doctor could also add another type of medication known as leukotriene receptor blockers: e.g. montelukast, zafirlukast, or zileuton, which block the production of leukotriene.

One of the chemicals produced by the immune system involved in urticaria /angioedema formation is a substance known as leukotriene, so by inhibiting the action of this substance, urticaria/angioedema formation decreases.

While taking these drugs, the patient needs to follow with his doctor and monitor his liver enzymes regularly.
The doctor can add a 1st generation antihistamine at bed time.

• Doxepin is an antidepressant that has both H1 and H2 antihistamines properties. It can be use, but it causes sedation.

If the symptoms are still not controlled, the case is said to be refractory; the doctor will consider using an anti-inflammatory or immunosuppressive drug:

• Corticosteroids can be used for a short time (few weeks) in severe or persistent cases, but because of their side effects, it is preferred not to use them for a long period of time.
• Cyclosporine is an immunosuppressive drug that can be used in persistent cases with no response to steroids especially autoimmune urticarial or as a steroid sparing agent in patient who had a response, but it has many side effects (e.g. it can damage the kidney and increase blood pressure)

Other immunosuppressive drugs that can be used:

E.g. dapsone, sulfasalazine, hydroxychloroquine colchicine, Mycophenolate

These are highly effective, but require frequent monitoring with different laboratory testing to check for any side effects.

Intravenous immunoglobulins are also effective in refractory cases.

Omalizumab is an IgE antibody that was found to be effective in the treatment of chronic urticaria/angioedema in patients with symptoms not controlled by H1 antihistamines. It prevents the IgE mediated activation of mast cells and the release of histamine which prevent urticaria/angioedema formation. No monitoring is required.

After the symptoms become fully controlled, the patient will have to continue on the same treatment for two to three months before the dose can be reduced gradually or the medications stopped. This should be done after a physician consult.