Urticaria

What is Urticaria?

Urticaria is also known as hives, weals, welts or nettle rash in Singapore. It manifests as a raised, itchy and red rash that appears on the skin, either on one part of the body or across large areas. The rashes range in size – they can go from a few millimetres to being palm-sized.

What are the different types of Urticaria in Singapore?

• Acute Urticaria - This type of rash will disappear within 6 weeks.
• Chronic Urticaria - This type of rash is persistent and comes and goes for more than 6 weeks over many years.
• Urticaria Vasculitis - This is a rare form of urticaria that causes inflammation of the blood vessels inside the skin. The weals in this case last longer than 24 hours and are much more painful, and can also cause bruising.

Common causes of Urticaria (Hives) in Singapore?

Urticaria is caused by high levels of histamine and other chemicals released in the skin when triggered. They cause blood vessels to dilate and become leaky, thereby causing the redness, swelling and itching.

The body may be triggered to release histamine due to a variety of factors, such as:

• An allergic reaction – such as allergy to food, insect bites or stings
• Cold or heat exposure
• Infections – like flu infections and urinary tract infections
• Certain medications – like non-steroidal anti-inflammatory drugs (NSAIDs) or antibiotics

That said, many cases of urticaria often happen without obvious reasons.

Some cases of chronic urticaria may be due to autoimmune conditions where your body’s own immune system attacks your healthy tissues. However, such cases are difficult to diagnose and there is no other special way to treat them. Certain triggers of urticaria include:

• Alcohol or caffeine
• Emotional stress
• Warm temperatures
• Prolonged pressure on the skin – often caused by tight clothing
• Certain food additives – like salicylates

What are the symptoms of Urticaria?

Some symptoms of urticaria include:

• Red, raised welts or bumps
• Blanching – where the centre of the hive turns white when pressed
• Itching
• Swelling

What are the risk factors for Urticaria?

Some risk factors or urticaria include:

• Personal history of allergies
• Personal history of urticaria
• Family history of urticaria
• A known disorder associated with hives – such as urinary tract infections or strep throat infections
• Frequent viral infections
• Medications
• Existing skin sensitivities or dermatitis (skin inflammation)
• Existing sensitivities to disinfectants, dyes, chemicals or perfumes
• Emotional triggers associated with stress and anxiety

What are the treatment options available for Urticaria in Singapore?

• Allergy Medications - Medications such as antihistamines are able to block the effects of histamine such that you experience relief from the itching and control your allergic reactions.
• Allergy Shots - For chronic hives which do not respond to medications, your doctor may recommend injection of a drug called omalizumab which blocks the body’s allergy antibody, immunoglobulin E (IgE), from causing allergic reactions. In severe allergies, there can be too much IgE that results in hives and asthma attacks.
• At-Home Treatments - Taking a cold shower or bath may help to relieve the itching. You may wish to wear loose-fitting clothes and apply a cold compress.
  There are also over-the-counter options like hydrocortisone creams to soothe the itching and swelling.
• Epinephrine - Severe allergic reactions may lead to something life-threatening – anaphylaxis. It can lead to shortness of breath and swollen airways, which require immediate injections of epinephrine to relieve symptoms.
• Oral Steroids - Oral steroids such as corticosteroids can relieve hive symptoms if antihistamines don’t work.