Urticaria, clinically known as hives, is a condition where patients experience transient, itchy, red welts on the skin.
Types of urticaria include:
| Type of urticaria | Characteristics and triggers of urticaria |
| Acute Urticaria | Short-term hives lasting less than six weeks, often triggered by allergies, infections, or stress. |
| Chronic Urticaria | Persistent hives that occur daily or almost daily for more than six weeks, often with an unknown cause. |
| Physical Urticaria | Hives caused by physical stimuli like cold, heat, pressure, or exercise. |
| Dermatographism | Skin hives that appear within minutes of scratching or rubbing the skin. |
| Delayed-Pressure Urticaria | Hives that form hours after sustained pressure on the skin. |
| Aquagenic Urticaria | Rare hives triggered by contact with water, for example, after bathing or sweating. |
| Drug-induced Urticaria | Hives caused by an allergic reaction to medication, appearing shortly after drug intake. |
| Contact Urticaria | Localised hives that appear immediately after the skin comes into contact with an allergen or irritant. |
| Idiopathic Urticaria | Chronic hives without an identifiable cause, characterised by spontaneous, recurring episodes. |
Hives or urticaria occur when histamine and other substances are released inside the body, which causes the skin to swell and form itchy patches or welts. Sometimes, these reactions are due to allergic responses to certain proteins called allergens, which, while harmless to many, can trigger symptoms like hives in sensitive individuals.
A significant proportion of chronic urticaria cases are thought to be autoimmune in nature. In these instances, the immune system produces antibodies against a special cell in the skin known as the mast cell, which then releases chemicals, such as histamine, that act on the skin to cause swelling, redness and itch.
Understanding the specific triggers can help those affected by urticaria avoid these factors and prevent the onset of hives. Common triggers of urticaria include:
Urticaria manifests as:
Urticaria can affect anyone; nonetheless, certain individuals may have a higher propensity to develop hives due to specific risk factors, which include:
Urticaria, or hives, is typically diagnosed by a dermatologist, involving several steps:
Despite thorough evaluations, a large number of chronic urticaria cases remain idiopathic, meaning no clear cause can be identified. In these instances, our focus shifts to managing symptoms and improving quality of life through a combination of lifestyle modifications and medication.
The treatment for urticaria varies based on the individual's medical history and symptom severity. Common treatment options include:
How can I differentiate between urticaria and insect bites or other skin reactions?
Urticaria and insect bites look similar. However, urticaria lesions change rapidly, and individual spots usually last less than 24 hours, whereas insect bites and other reactions persist for days and evolve more slowly. Another clue to the diagnosis would be the distribution of the rashes. Urticaria can appear anywhere on the body and often in large areas, while insect bites are more localised and confined to specific exposure sites.
How effective are biologics in treating chronic urticaria?
Biologic therapies such as omalizumab are effective in treating chronic urticaria, especially for cases that have not responded well to traditional treatments such as antihistamines or corticosteroids.
The reduction in daily symptoms allows for a return to normal activities without the constant concern of a urticaria flare-up. Additionally, because omalizumab is specifically targeted, it tends to have fewer side effects than systemic corticosteroids or other traditional immunosuppressants. If you are struggling with chronic urticaria and traditional treatments have not been effective, consider scheduling a consultation to discuss whether biologics could be an appropriate option for you.
What causes urticaria to flare up?
Urticaria, or hives, can flare up due to various triggers, including allergic reactions to foods, medications, or insect stings, exposure to physical stimuli like heat or cold, infections, stress, and underlying health conditions. Identifying and avoiding personal triggers is key to managing flare-ups.
Is urticaria contagious?
Urticaria is not contagious and cannot be transmitted from one person to another. It is an immune response or reaction to certain external or internal factors within an individual's body.
Can urticaria lead to other health complications?
While urticaria itself is usually not serious, chronic or severe cases can sometimes be associated with other health issues, such as autoimmune disorders, underlying haematological abnormalities or thyroid problems.
