Urticaria

Hives are red and sometimes itchy bumps on the skin. It is generally caused due to an allergic reaction to a drug or food. Allergic reactions cause body to release chemicals that can make skin swell up in hives. People who have other allergies are more likely to get hives than other people. Other causes include infections and stress.

Classification:

• Acute urticaria is defined as the presence of wheals which completely resolve within six weeks. Acute urticaria becomes evident a few minutes after the person has been exposed to an allergen. The outbreak may last several weeks, but usually the hives are gone in six weeks.

• Chronic urticaria (ordinary urticaria) is defined as the presence of wheels which persist for greater than six weeks. Some of the more severe chronic cases have lasted more than 20 years

References: www.nhs.uk
www.nlm.nih.gov
www.nlm.nih.gov
www.aad.org

• Appear as small round wheals, rings or patches and may change shape
• Itching may be accompanied by a red flare
• Often appear on the face or the extremities
• Sometimes it  lasts from 30 minutes to 36 hours. As some patches disappear, new patches may develop

Reference: www.nlm.nih.gov

Urticaria is caused by the release of histamine and other chemicals from under the skin's surface, causing the tissues to swell.

Some risks factors:

• An allergic reaction to food, such as peanuts, shellfish, eggs and cheese
• An allergic reaction to environmental factors such as pollen, dust mites or chemicals
• An allergic reaction to latex, which can be a common problem in healthcare workers
• Infections, which can range from relatively trivial such as a cold to very serious such as HIV
• Insect bites and stings
• Emotional stress
• Some medications, which can cause urticaria as a side effect, including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, and antihistamines
• Physical triggers, such as pressure to the skin, change in temperature, sunlight, exercise or water.

Reference: www.nhs.uk

Urticaria is generally diagnosed by looking at the rashes on the skin. Doctor may ask about the allergens and any medications.

It generally involves symptomatic relief. Various medications included are

Antihistamines: Medicines like Cetirizine, Fexofenadine and Loratadine

Corticosteroid tablets: Medicines like prednisolone

Reference: www.nlm.nih.gov

Urticaria can further lead to:

Angioedema: Around half of people with chronic (persistent) urticaria and a quarter of people with acute (short-term) urticaria also get a related condition called angioedema.

• Avoid known triggers: These may include certain foods or food additives, alcohol, medications, or situations such as temperature extremes, tight clothing or emotional stress.
• Keep a diary: Track all of your activities, when and where hives occur, and what you eat. This may help you and your doctor identify triggers.
• Avoid medications that may trigger Urticaria: These include aspirin, ibuprofen (Advil, Motrin, others), naproxen sodium (Aleve, Anaprox, others), codeine or any other medication that you've noticed can trigger your hives.