How to Treat Hives?

What are hives?

Hives are an allergic skin reaction that causes localised redness, swelling, and itching. This immune system response leads to raised, red patches known as wheals. When the reaction affects small areas, it's called “urticaria.” If larger areas, like entire sections of a limb, are involved, it's referred to as “angioedema.”

What are the symptoms of hives?

Urticaria is marked by redness, swelling, and itching in small areas of the skin. These patches typically appear and disappear within a day, though new hives may form elsewhere.

Angioedema involves more widespread swelling, which can affect the airways, leading to wheezing and respiratory distress. In severe cases, this can cause airway obstruction.

What causes hives?

Hives are an allergic reaction triggered when the body’s immune system becomes sensitised to typically harmless substances, known as allergens. Normally, the immune system protects against foreign invaders, but in this case, it reacts inappropriately. When an allergen is ingested, inhaled, or comes into contact with the skin, it interacts with mast cells in the skin, airways, and digestive system. These cells release histamine and other chemicals, both locally and into the bloodstream, causing blood vessels to become more porous. This allows fluid to accumulate in tissues, leading to the swollen, reddish appearance of hives. Additionally, these chemicals sensitise pain nerve endings, making the affected area itchy and sensitive. Various substances, including foods, drugs, and insect bites or stings, can trigger hives in sensitive individuals.

Which factors can cause hives?

• Nuts, especially peanuts, walnuts, and Brazil nuts
• Fish, mollusks, and shellfish
• Eggs
• Wheat
• Milk
• Strawberries
• Food additives and preservatives
• Penicillin or other antibiotics
• Flu vaccines
• Tetanus toxoid vaccine
• Gamma globulin
• Bee, wasp, and hornet stings
• Bites of mosquitoes, fleas, and scabies

How do dermatologists diagnose hives?

When a patient has hives, a dermatologist can often diagnose the condition by examining the skin. However, identifying the cause of hives can be challenging, especially if they persist for more than six weeks. To determine the cause, your dermatologist will review your health history, ask detailed questions, and perform a physical examination. You may also need the following tests:

1. Allergy tests: These can be done on the skin or through blood tests.

2. Blood work: This helps rule out underlying illnesses or infections.

3. Skin biopsy: In this procedure, the dermatologist removes a small piece of affected skin to examine it under a microscope.

How to treat hives?

For mild hives, treatment typically involves antihistamines like diphenhydramine (Benadryl) or non-sedating options such as desloratadine (Clarinex), which won't cause drowsiness. In more severe cases, oral corticosteroids like prednisone may be necessary, while topical corticosteroids are ineffective. If airway swelling occurs, an emergency injection of epinephrine (adrenaline) is required.

In Singapore, the most common treatment for mild to moderate hives is a non-sedating antihistamine. These medications effectively relieve symptoms like itching, helping you find comfort and relief.

If you have chronic hives, your dermatologist may prescribe an antihistamine for daily use to prevent outbreaks. With many antihistamines available, some cause drowsiness while others do not. Since no single antihistamine works for everyone, your dermatologist might combine it with other medications to manage your hives effectively. Additional treatments for hives may include:

• Cortisones (for short-term use only because of side effects with long-term use).

• Dapsone, an antibacterial.

• Other medicines that fight inflammation (redness and swelling).

• Ask your dermatologist about possible side effects (health problems that can result from the medicines).

• For some cases of hives or angioedema, you may need an injection of epinephrine (shot of adrenaline).

How to prevent hives?

Preventing hives involves identifying and avoiding the allergens that trigger them. Analysing new foods in your diet or recently taken medications can help pinpoint the likely source of the reaction. For those with chronic hives, reducing stress and avoiding caffeine, alcohol, and tobacco may help decrease the frequency of outbreaks.

When will hives go away?

A hive often will go away in 24 hours or less, but bouts can last longer. A few people have chronic hives (lasting more than six weeks). Sometimes chronic hives go away on their own — often within a year. For others, hives can come and go for months or years.