Definition
Hives are medically known as urticaria, it appears on any part of the skin. It causes itchy welts from small to big blotches for various inched in diameter. It is caused by some allergic reactions. It is formed by the responsibilities of histamine that causes tissues to swell and itchy red rashes. The histamine and fluids from the capillary will accumulate in the skin and causes itching, swelling and rashes.
Epidemiology
Approximately 15% of people experience urticaria at some time in their lives. Acute urticaria is much more common than chronic urticaria. (Estimated lifetime incidence is 1 in 6 people compared to 1 in 1,000.) The prevalence rate for chronic urticaria has been estimated as 1-5 per 1,000. Acute urticaria is most common in children and is more common in women than in men, particularly in the 30-60 age range. It is more common in individuals who have atopy.
Types
There are main two types of hives such as:
Acute utricaria: The symptoms will last less than six or eight weeks.
Chronic utricaria: In rare cases it last for a long period of time more than six to eight weeks, sometimes the rashes comes and goes for over many years.
Based on the cause, doctors classify hives into different types:
Solar utricaria: It is caused by exposure into the sun
Physical utricaria: It is affected by heat, sun exposure, vibration, exercise, cold and pressure to the skin. This type of hives may only be found where the skin was affected can appear within an hour of the exposure.
Dermatographic urticaria: It is caused after firm stroking or scratching of the
Cholinergic urticaria: It is caused by increased body temperature, stress, exercise and having baths.
Urticaria pigmentosa: It causes red or brown swelling or markings and it will mostly affect children
Autoimmune urticaria: Some of the autoimmune conditions such as lupus or rheumatoid arthritis are linked to hives.
Urticaria vasculitis: In this type of hive the blood vessels got inflamed under the skin.
Idiopathic urticaria: Stress may be a trigger, But No obvious cause found.
Hereditary angioedema: This is painful swelling of tissue. It is passed on through families.
Risk factors of Hives
Some of the increased risk factors of acute and chronic hives are as follows:
- Existing or newly developed allergies
- Patient history of hives
- A family history of hives
- The disorders that associated with hives are urinary tract infection, strep throat, hepatitis, rheumatoid arthritis, or type 1 diabetes
- Common viral infections
- Medications such as allergic and non-allergic mechanisms, including codeine, aspirin, morphine, and NSAIDs
- Current skin sensitivities or dermatitis such as inflammation of the skin
- Sensitivities due to disinfectants, dyes chemicals and perfumes.
- Emotional triggers (associated with stress and anxiety)
Causes
Foods: Foods that causing side effects in people with sensitivities such as shellfish, fish, peanuts, tree nuts, eggs and milk are frequent offenders.
Common allergens: Allergens that cause hives such as pollen, animal dander, latex and insect stings.
Environmental factors: Heat, cold, sunlight, water, pressure on the skin, emotional stress and exercise.
Medications: Mostly any medications cause hives. Some of the prevalent medications such as aspirin, ibuprofen (Advil, Motrin IB, others), naproxen (Aleve) and blood pressure medications.
Basic medical conditions: Hives also hardly occurs in response to blood transfusions, immune system disorders such as lupus, some types of cancer such as lymphoma, certain thyroid conditions, and infections with bacteria or viruses such as hepatitis, HIV, cytomegalovirus, and Epstein-Barr virus.
Histamine release: Histamine is a chemical released from specialized cells along the skin’s blood vessels.
Histamine release causes hives
Causes of hives
Symptoms of Hives
Symptoms of hives include:
- Increased red rash
- Swelling of surrounding tissue
- Pain in the inflamed area
- Itching and burning of skin
Rashes on skin
Diagnosis and test
Urticaria is often diagnosed by looking at the skin. Finding the cause of the hives is challenging. To find the cause of the hives, your doctor may do a physical examination and to review your health history. Some of the diagnosing tests include as follows:
- Allergy test on skin or in the blood
- Skin biopsy
- Blood work ( to rule out an illness or infection)
Skin biopsy is done by removing a small piece of your affected skin and it can be examined under microscope.
Treatment and medications
If symptoms are mild treatment is not needed. In many cases of urticaria it cures by its own. But treatment can relief some intense of serious discomfort.
Medications:
Medications for hives include:
Anti-itch drugs: The anti-itch drugs such as antihistamines that reduces itching swelling and other allergy symptoms. some of the antihistamine drugs are as follows.
- Oratadine [Claritin]
- Fexofenadine [Allegra]
- Cetirizine [Zyrtec]
- Diphenhydramine [Benadryl]
- Hydroxyzine [Vistaril]
- Chlorpheniramine [Chlor-Trimeton]
Anti-inflammatory drugs: For severe hives, doctors may prescribe an oral corticosteroid drug such as prednisone to reduce swelling, redness and itching.
Drugs that reduce pain and swelling: Chronic hives and angioedema may be treated with a type of nonsteroidal, anti-inflammatory medication called leukotriene antagonists.
Drugs that suppress the immune system: If antihistamines and corticosteroids are ineffective, your doctor might prescribe a drug capable of calming an overactive immune system. Prednisone is a corticosteroid, helps to relieve swelling, redness, and itching, and also can prevent hives from coming back.
Prevention of Hives
Simple habits changes to your lifestyle may be able to help you prevent hives from reoccurring in the future.
- If you have allergies and you know which substances are likely to cause an allergic reaction, your doctor will suggest that you avoid any possible exposure to these factors.
- Allergy shots are another option that may help you reduce the risk of experiencing hives again.
- Avoid being in high-humidity areas or wearing tight clothing if you have recently had a hives outbreak.