Have you ever experienced intermittent itchiness on your skin without a clear cause? This can be frustrating and disrupt your daily life, even if you’ve checked your environment and the products you use.

Such symptoms might be due to urticaria, commonly known as hives. Urticaria is a skin condition characterised by red, itchy welts. Although the itchiness might be temporary, the condition can recur, making it challenging to manage without identifying the underlying cause.

Sunil Jaiswal, a consultant dermatologist and lecturer at Chitwan Medical College, discusses urticaria's causes, symptoms, and treatment.

What is urticaria, and how does it occur?

Urticaria, a common condition driven by mast cells, affects about 3-5 percent of people. It appears as recurring itchy hives on various parts of the body. These wheals are temporary, disappearing within 24 hours, and are marked by a central pale area surrounded by redness. Their size can range from a few millimetres to several centimetres in diameter. In some cases, urticaria patients may also experience angioedema, which involves painful swelling of the deeper layers of the skin, subcutaneous tissue, and mucous membranes.

Can you explain its types and how they differ in symptoms and causes?

Urticaria can be classified based on how long the symptoms last and whether there are identifiable triggers.

Acute urticaria lasts less than six weeks and is often caused by triggers such as certain foods (nuts, milk, shellfish, eggs), medications (antibiotics, NSAIDs), insect stings, parasites, contact allergens, and infections. About one-third of those with acute urticaria may develop chronic urticaria.

Chronic urticaria persists for over six weeks, with episodes recurring for months or even years. It is often linked to autoimmune disorders (like autoimmune thyroiditis, systemic lupus erythematosus, dermatomyositis, and rheumatoid arthritis) or chronic infections (such as hepatitis B and C, herpes simplex virus, Helicobacter pylori, and helminth parasites). In most chronic cases, the cause is unknown and referred to as chronic idiopathic urticaria. Some individuals experience chronic urticaria triggered by physical stimuli, known as chronic inducible urticaria, including scratching (dermatographism), cold, heat, sunlight (solar urticaria), vibration, pressure, exercise (cholinergic urticaria), and water (aquagenic urticaria). Wheals from physical triggers usually appear quickly, are localised to the affected area, and typically resolve within 2 hours, except for delayed pressure urticaria.

Why do some individuals seem more susceptible than others?

The likelihood of developing urticaria can be linked to several factors, including genetic predisposition, immune system overactivity to both immunological and non-immunological stimuli, and environmental and lifestyle influences. Individuals with a family history of allergies or atopy, those with underlying autoimmune diseases, and those frequently exposed to allergens or infections are more prone to urticaria, especially if they have a genetic susceptibility.

How is urticaria diagnosed, and what tests are performed to identify its causes?

Urticaria is primarily diagnosed through clinical evaluation, with investigations to identify its cause. Standard tests include Complete Blood Count (CBC), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), and thyroid autoantibodies. Additional tests like skin prick tests, serum specific IgE, and Autologous Serum Skin Test (ASST) can be helpful but are not routinely performed. Challenge testing, where patients are exposed to suspected triggers, is often used to confirm chronic inducible urticaria. It's also crucial to differentiate urticaria from urticarial vasculitis, which presents with painful, long-lasting lesions that cause skin discolouration, unlike the usually itchy, brief wheals of urticaria.

Treatment focuses on addressing any underlying conditions, minimising exposure to known physical triggers and allergens, avoiding trigger foods and medications, exercising in cooler environments for cholinergic urticaria, and following a stepwise approach with antihistamines, short courses of steroids, leukotriene antagonists, and immunosuppressives to reduce the frequency and severity of outbreaks.

How to treat it?

Second-generation non-sedating H1-receptor antihistamines (such as fexofenadine, desloratadine, loratadine, cetirizine, and bilastine) are the primary treatment for urticaria. A standard daily dose is most effective and should be maintained consistently rather than taken only as needed. If symptoms are well-controlled, treatment should continue for several weeks to months. Recent studies suggest that gradually tapering off antihistamines, rather than stopping abruptly after symptoms are controlled, can lead to better long-term management.

For patients whose symptoms persist despite standard doses over 2-4 weeks, the antihistamine dose may be increased up to four times the recommended amount. If urticaria remains resistant to H1 antihistamines, leukotriene receptor antagonists (like montelukast) can be added. In severe cases, a short course of oral corticosteroids may be necessary.

How does urticaria affect daily life?

Chronic urticaria can cause significant impairment in the patient’s quality of life due to associated pruritus and loss of sleep. It can hurt work, school, social activities and even lead to anxiety and depression as well.

Are there any emerging treatments or therapies that treat this?

Recent studies have shown that Omalizumab (an anti-IgE humanised monoclonal antibody) and cyclosporine are emerging therapies for chronic urticaria patients who are resistant to higher doses of antihistamines, and they are showing promising results.