Urticaria

Urticaria is a skin reaction characterised by the sudden appearance of red or skin-coloured welts (hives) that are usually itchy and may feel like stings or burns. These welts can vary in size and shape. It often changes location within hours. While individual hives typically resolve within a day, new ones may appear.

In some cases, hives are accompanied by angioedema, which is a deeper swelling that affects the eyelids, lips, hands, feet or genitals. Angioedema often feels tight, puffy or painful rather than itchy. 

Hives are not contagious. But discomfort and unpredictability can disrupt sleep, daily activities and overall quality of life. In some cases, urticaria is short-lived (acute), while in others, it may persist for weeks or months (chronic).

What are the types of Urticaria?

The condition is broadly classified into 2 main categories, which are:

• Acute urticaria – lasts less than 6 weeks. It is often triggered by infections, foods (such as shellfish, nuts, eggs), insect stings, medications or environmental factors like cold or heat.

• Chronic urticaria – persists for 6 weeks or longer. Most of the time, the exact cause is difficult to pinpoint. It may be linked to autoimmune responses, thyroid disorders or ongoing low-grade allergic triggers.

• Physical or inductible urticaria – hives are triggered by specific physical stimuli, such as pressure on the skin, scratching (dermographism), cold, heat, sunlight or exercise-induced sweating. Symptoms usually appear soon after the stimulus and settle once the trigger is removed.

Some people also develop physical urticaria, where hives occur in response to physical stimuli such as pressure, sunlight, temperature changes, vibration or exercise.

Where can Urticaria appear?

Hives can show up anywhere on the body. However, they often appear on the arms, legs, trunk and face, but may shift or spread within hours.

Some people also develop angioedema, which is a deeper form of swelling. This typically affects the eyes, lips, hands, feet or genitals and may feel tight or uncomfortable.

If swelling involves the tongue or throat and causes difficulty breathing, swallowing or speaking, it is important to seek urgent medical care.

What causes Urticaria?

It often develops when certain substances or stimuli activate the skin’s immune response. The triggers vary depending on the type, which includes:

Allergic triggers (IgE-mediated):

These occur when the immune system overreacts to a specific allergen.

• • Foods such as shellfish, nuts, eggs or dairy
  • Insect stings or bites
  • Some antibiotic allergies

• Latex or environmental allergens

Non-allergic (histamine-releasing) triggers:

These do not involve IgE allergy but can directly cause histamine release.

• Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen or diclofenac
• Alcohol, preservatives or artificial colouring
• Opioids or contrast dyes that are used in medical imaging

Physical or inducible urticaria

Hives that are triggered by specific physical factors.

• Pressure from tight clothing, straps or prolonged sitting
• Sunlight exposure
• Temperature changes such as heat, cold or sudden sweating
• Vibration or friction on the skin

Chronic spontaneous urticaria:

In many cases, there is no clear external trigger. But it is often associated with:

• Autoimmune responses
• Hormonal fluctuations
• Infections or underlying medical conditions
• Stress or emotional factors

What are the symptoms of Urticaria?

The appearance and severity of symptoms can vary. But it generally involves:

• Burning or stinging sensation in affected areas
• Intense itching, often worse at night
• Raised welts or bumps that are either red, pink or skin-coloured
• Welts that change shape or location within hours
• Swelling of lips, eyelids or face (angioedema) 

While hives themselves are uncomfortable but usually harmless, sudden swelling can be a sign of an allergic reaction. Seek immediate medical attention if it involves the throat or tongue, causes difficulty breathing or shortness of breath.

Who is at risk of developing Urticaria in Singapore?

Singapore’s hot, humid climate, coupled with dietary habits and high allergen exposure, makes urticaria relatively common. However, there are some groups that are more prone to developing the condition.

These risk factors include:

• Gender – women are more susceptible to chronic urticaria due to hormonal factors, such as menstruation, pregnancy or menopause. These conditions are thought to influence immune activity and increase flare-ups.
• Children – viral and bacterial infections are more common in younger age groups. Their immune systems may react more strongly, making infection-related hives more likely.
• Individuals with allergies – people with asthma, allergic rhinitis or eczema already have an overactive immune system. This heightened sensitivity increases the likelihood of their body releasing histamine, which triggers hives.
• People with autoimmune conditions – conditions like thyroid disease or lupus can cause the immune system to attack the body’s tissues. This dysregulation can also provoke the release of histamine, leading to hives.
• Environmental exposure – frequent contact with potential triggers such as seafood, medications, insect bites or tropical plants raises the chance of immune activation in sensitive individuals. This results in repeated outbreaks of hives.

How is Urticaria diagnosed?

Diagnosis is usually straightforward. But it requires careful evaluation to identify possible causes and rule out other conditions.

Our dermatologist will take a step-by-step approach that may include:

• Detailed medical history – this helps uncover patterns such as when the hives began, how long they last, possible triggers, medications taken, lifestyle factors and whether there is a family history of allergies or autoimmune disorders.

• Physical examination – our dermatologist will assess the size, shape and distribution of the hives. They will also observe if these hives change or move over time. This examination can also identify associated swelling (angioedema).

• Laboratory tests – in persistent or unclear cases, blood work, skin prick tests or other allergy tests may be carried out. These are performed to detect underlying infections, autoimmune conditions or allergen sensitivities.

• Exclusion of other conditions – some skin disorders, such as eczema, contact dermatitis, vasculitis or autoimmune rashes, can resemble urticaria. Ruling these out ensures the right treatment plan.

What are the treatment options for Urticaria in Singapore?

The management of the condition often focuses on relieving symptoms, preventing flare-ups and addressing underlying causes where possible. It is usually a combination of the following treatments:

Medications

• Non-sedating antihistamines – these are the first-line treatment for most patients. They help relieve itching and reduce the appearance of welts and can be taken daily in cases of chronic urticaria to keep symptoms under control.
• Higher-dose antihistamines – if regular doses are not enough to manage symptoms, guidelines recommend increasing the dose of the same second-generation antihistamine, up to four times the usual amount. This approach is preferred over switching to a sedating antihistamine or combining multiple types.
• Corticosteroids – short courses of oral corticosteroids may be used to quickly control severe and acute flare-ups. However, they are not recommended for long-term use due to potential side effects.
• Immunomodulators or biologic therapies – in chronic urticaria that does not respond to conventional treatment, advanced options such as immunomodulators or biologics like omalizumab should be considered to target the underlying immune response.

Lifestyle modifications

• Identifying and avoiding known triggers – this may include certain foods, medications, temperature extremes or stress. Keeping a symptom diary can help spot patterns and reduce flare-ups.
• Wearing loose and breathable clothing – soft fabrics minimise friction and irritation. This helps to reduce itching and discomfort.
• Applying cool compresses – a simple, non-medicated option that provides temporary relief from itching and swelling.
• Maintaining a regular sleep routine – adequate rest helps the body recover, while fatigue and stress can make hives worse.

Long-term management

For those with chronic urticaria, regular follow-up with a dermatologist is essential. Ongoing care allows treatment plans to be adjusted as needed, ensures that medications are used safely and helps monitor for associated conditions such as thyroid disease or other autoimmune disorders.

Summary

Living with hives can be frustrating, not only because of the sudden and unpredictable flare-ups, but also because of how they affect daily comfort, sleep and confidence. The good news is that urticaria is a manageable condition. With the right support, most people find that their symptoms improve greatly.

An accurate diagnosis helps uncover possible triggers, while tailored treatment and lifestyle guidance from a dermatologist can ease itching, reduce flare-ups and restore peace of mind. With ongoing care, many patients achieve long-term relief and regain a sense of control over their skin and overall well-being.

If you have been suffering from urticaria, then call us to schedule an appointment with one of our dermatologists at Dermatology Collective.