Hives also known as Nettle rash and Urticaria, are red, swollen wheals on the skin that itch, burn or sting. It appears in varying sizes from size of a coin to size of a plate, appears suddenly and lasts from an hour to 24 hours. They show blanching that is when the red wheal is pressed in it’s centre it turns white.

What causes hives?

Hives can be caused by a variety of factors, including:

1. Allergies: Hives can be caused by an allergic reaction to food, medications, insect stings, or other allergens.
2. Infections: Bacterial, viral, or fungal infections can sometimes cause hives.
3. Physical triggers: Hives can be triggered by physical stimuli such as pressure, heat, cold, exercise, or sun exposure.
4. Stress: Emotional or psychological stress can sometimes cause hives.
5. Medications: Certain medications, including aspirin, ibuprofen, and antibiotics, can cause hives as a side effect.
6. Underlying medical conditions: Hives can be a symptom of underlying medical conditions such as autoimmune diseases, thyroid disorders, or liver disease.

What is the pathophysiology of hives?

The pathophysiology of hives involves the release of histamine and other chemical mediators from mast cells in response to an inciting trigger.

In individuals with hives, the immune system mistakenly identifies a substance as harmful and releases histamine and other chemical mediators from mast cells in the skin. This release of histamine and other mediators causes the blood vessels in the affected area to become dilated and leaky, leading to the characteristic redness, swelling, and itching of hives.

In some cases, hives can be caused by the activation of immune cells called basophils, which also release histamine and other mediators. In others, hives can be triggered by the activation of nerve fibers in the skin, leading to the release of histamine and other mediators.

The exact mechanisms that trigger the release of histamine and other mediators in hives are not fully understood. However, it is thought to involve a combination of genetic, environmental, and lifestyle factors.

How long does it last?

The duration of hives can vary depending on the underlying cause and severity of the reaction. In many cases, hives will resolve on their own within a few hours to a few days. However, in some cases, hives can persist for several weeks or even months.

If the hives are caused by an underlying medical condition or a medication, they may recur and last for an extended period of time. In these cases, treatment of the underlying condition or change in medication may be necessary to resolve the hives.

If you are experiencing hives, it is important to talk to your doctor to determine the cause and appropriate treatment. They may also recommend over-the-counter or prescription medications to relieve the itching and swelling associated with hives.

What are the signs and symptoms of hives or urticaria?

The signs and symptoms of hives, also known as urticaria, can vary in appearance, duration, and severity. Common symptoms of hives include:

1. Red, raised, itchy welts on the skin: Hives are usually round or oval in shape and can range in size from a few millimeters to several inches in diameter.
2. Welts that change shape and location: The welts associated with hives can change shape and move to different areas of the skin over time.
3. Swelling: Hives can cause swelling, especially around the eyes, lips, and hands.
4. Itching: Hives can be intensely itchy.
5. Burning or stinging sensation: Some people with hives may experience a burning or stinging sensation in the affected area.

In some cases, hives can be accompanied by other symptoms such as a runny nose, watery eyes, and difficulty breathing, indicating an allergic reaction. In these cases, it is important to seek medical attention as soon as possible as this can be a sign of a potentially life-threatening condition known as anaphylaxis.

What are the various types of hives?

There are several different types of hives, including:

1. Acute hives: This type of hives occurs suddenly and lasts less than 6 weeks. It is usually caused by an allergen or infection and typically resolves on its own within a few days.
2. Chronic hives: This type of hives lasts for more than 6 weeks and can persist for several months or even years. It is often caused by an underlying medical condition or medication and may require treatment to resolve.
3. Physical hives: This type of hives is caused by physical triggers such as pressure, heat, cold, exercise, or sun exposure. Physical hives typically resolve on their own within a few hours.
4. Cholinergic hives: This type of hives is caused by sweating and occurs in response to changes in body temperature. It typically resolves on its own within a few hours.
5. Dermatographic hives: This type of hives is caused by skin pressure or friction and occurs in response to skin being rubbed or scratched. It typically resolves on its own within a few hours.
6. Cold hives: This type of hives is caused by exposure to cold temperatures and typically resolves on its own within a few hours.

Management

The management of hives depends on the severity and underlying cause of the condition. In many cases, the following measures can be used to manage hives:

1. Avoid triggers: If you know what triggers your hives, it is important to avoid these triggers to prevent future outbreaks. Common triggers include certain foods, medications, and insect bites.
2. Over-the-counter antihistamines: Over-the-counter antihistamines, such as diphenhydramine (Benadryl) and loratadine (Claritin), can be used to relieve the itching and swelling associated with hives.
3. Prescription antihistamines: If over-the-counter antihistamines are not effective, your doctor may prescribe a stronger antihistamine, such as cetirizine (Zyrtec) or fexofenadine (Allegra), to relieve your symptoms.
4. Corticosteroids: In severe cases of hives, your doctor may prescribe a short course of oral corticosteroids, such as prednisone, to reduce inflammation and relieve symptoms.
5. Avoiding tight clothing: Wearing loose, breathable clothing can help prevent skin irritation and reduce the likelihood of hives.
6. Cold compresses: Applying a cold compress to the affected area can help relieve itching and swelling.
7. Moisturize your skin: Keeping your skin well-moisturized can help prevent dry skin, which can trigger hives in some people.

In addition, if the hives are caused by an underlying medical condition or medication, treating the underlying cause may be necessary to resolve the hives.

If you are experiencing hives, it is important to talk to your doctor to determine the cause and appropriate treatment. They may also recommend lifestyle modifications and additional medications to relieve your symptoms and prevent future outbreaks.