“Ask Dr. HKSH” – Urticaria

Dr. CHAN Chun Yin, Johnny

Specialist in Dermatology & Venereology

Q1. What are “hives” or “alcohol hives”?

“Hives” or those caused by alcohol consumption refer to the same medical condition, known clinically as urticaria. Urticaria is a common skin condition that may be triggered by allergic reactions or immune dysfunction. According to studies, it is very prevalent—approximately 20% of the population will experience one or more episodes of urticaria during their lifetime.

Q2. Is urticaria the same as eczema?

This is a good question. Many patients ask about this. Urticaria and eczema (atopic dermatitis) are two entirely different conditions. The weals caused by urticaria are typically red and swollen, with well-defined borders separating them clearly from the surrounding normal skin. Most importantly, urticaria does not cause skin scaling or peeling.

In contrast, eczema usually presents with ill-defined borders, less prominent swelling, and significant scaling. It is essential to differentiate between these two conditions, as their treatment and management are different.

Q3. What other conditions may resemble urticaria?

A similar condition is urticarial vasculitis. As an autoimmune-mediated condition, it is generally more serious than simple urticaria. It occurs when the immune system mounts an abnormal response and attacks the blood vessels. Clinically, it may appear similar to urticaria; however, some lesions are often more persistent and resistant to treatment, possibly associated with subcutaneous bleeding. This condition is potentially dangerous and that requires further evaluation.

Q4. Apart from itchiness and redness, what other symptoms may occur in urticaria?

In addition to the typical itchy, erythematous weals, a more serious and clinically significant manifestation of urticaria is angioedema. Angioedema is a particular form of urticaria that commonly affects the face and neck. The swelling is usually more severe and may involve mucosal tissues, including the lips, tongue, throat, and upper airway. Severe swelling in these areas may make breathing difficult. If angioedema involves the upper respiratory tract, it can become life-threatening.

Q5. What are the causes of urticaria?

Urticaria has many possible causes. It can be classified into acute and chronic urticaria.

Acute urticaria usually resolves spontaneously within six weeks. It is commonly related to allergic reactions to foods or medications. Another cause of acute urticaria is viral infection, which may trigger an immune response. This can occur following upper respiratory tract infections or gastrointestinal viral infections, leading to the sudden onset of urticaria.

Chronic urticaria is defined as urticaria that persists or recurs for more than six weeks. It is more commonly associated with immune dysfunction,  including autoimmune diseases such as systemic lupus erythematosus and thyroid disorders, etc. In addition, certain chronic infections, including hepatitis B, HIV infection, and tuberculosis may also be associated with chronic urticaria.

Q6. Should I seek medical attention when urticarial occurs? Is treatment still needed after the rash subsides?

In many cases, medical consultation is advisable. If acute urticaria resolves rapidly—such as within two days—after exposure to a known food or drug allergen, medical treatment may not be necessary. However, if symptoms persist for more than two days or recur repeatedly, medical advice is recommended for symptom control and identification of potential triggers, including food and drug allergens, which should be avoided to prevent recurrence.

If urticaria repeatedly relapses or persists for more than six weeks, suggesting chronic urticaria, medical assessment is essential. Further evaluation may be required to identify the underlying immune disorders or chronic infections, thereby achieving long-term control or symptom relief.

Q7. How can urticaria be prevented?

The approach to prevention depends on whether the condition is acute or chronic. For acute urticaria, prevention focuses on identifying and avoiding triggering foods or medications, as well as reducing the risk of infections. Most cases resolve spontaneously, and simple treatment measures are usually effective.

Chronic urticaria, however, requires a different approach. Investigation is needed to identify the underlying causes, such as autoimmune conditions or chronic infections. If no underlying cause is identified, symptomatic treatment is the mainstay of management. Oral antihistamines are generally effective in improving symptoms.

In more severe cases, high-dose non-sedating antihistamines can control most urticaria symptoms. If symptoms remain uncontrolled despite high-dose antihistamines, other treatment options may be considered. Newer treatments include biologic therapies, particularly those that neutralise immunoglobulin E (IgE)—one of the key antibodies involved in the development of urticaria. These treatments can significantly improve symptoms. In addition, certain biologic agents originally developed for atopic dermatitis (eczema) have been approved by the FDA for use in selected cases of severe urticaria, offering more sustained and effective symptom control.

Q8. How can discomfort be relieved during an episode of urticaria?

During an episode of urticaria, the most important step is to identify and remove the underlying cause. If urticaria is triggered by food or medication, avoiding the allergen often leads to significant improvement. If symptoms persist, the first-line treatment is oral antihistamines. These are first-generation and second-generation antihistamines. First-generation antihistamines may cause drowsiness and are therefore less well-tolerated, while second-generation (non-sedating) antihistamines are preferred for effective symptom relief with minimal sedation.

In more severe cases, the dosage of non-sedating antihistamines may be increased. If symptoms remain poorly controlled despite high-dose antihistamine therapy, additional treatment options are available. While conventional treatments such as immunosuppressive agents, such as systemic corticosteroids and non-steroidal immunosuppressants can effectively control symptoms. Due to potential side effects, their use is now more limited.

Biologic therapies have emerged as a safer and effective alternative. Among them, anti-IgE biologic agents are particularly important and commonly used. Since IgE plays a key role in the pathogenesis of urticaria, neutralising IgE can result in significant symptom improvement. Other newer biologic agents are being developed to target different inflammatory pathways, and may provide effective and sustained relief against urticarial.