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• What causes urticaria (hives)?
• What are the symptoms of urticaria (hives)?
• How is urticaria diagnosed?
• How are urticaria treated?
• What is the prevention of urticaria?
• What are the symptoms of night urticaria?

Urticaria (Hives)

Urticaria (hives) are itchy skin welts—a flare-up of raised red patches with a clear, distinct edge that suddenly appears on specific skin areas or spreads widely throughout the body, similar to insect bites. Urticaria is a skin reaction to allergens that the body is exposed to, and it can range in size from millimeters to palm size. Urticaria is typically relieved with antihistamines and resolves on its own within 24 hours. Acute urticaria can cause chest tightness, wheezing, shortness of breath, and even death due to anaphylactic reactions. Urgently seeking medical attention at a hospital is required if you have the above symptoms.

How many types of urticaria (hives)?

Urticaria (hives) can be classified into 2 types depending on duration, including:

1. Acute urticaria is a type of urticaria that lasts no longer than 6 weeks. Most resolve within one week, and less than 40% become chronic urticaria.
2. Chronic urticaria is a type of urticaria that lasts over 6 weeks with at least two episodes per week and persists for more than 1 year in most patients. Chronic urticaria could be spontaneous or inducible by definite triggers.

What causes urticaria (hives)?

1. Urticaria is caused by the bodily reaction to irregular immune system function, such as chronic urticaria due to the secretion of IgE antibodies, resulting in urticaria without being triggered by an external allergen.
2. Urticaria is caused by the bodily reaction to allergens found in the environment or chemicals contained in everyday objects that may cause allergies, which stimulate the secretion of histamine, a protein released from the mast cells through tissues, capillaries, and nerve endings. Factors that trigger urticaria or hives include:
   
   • Foods such as seafood, wheat flour, nuts, soybeans, wheat, eggs, milk, food coloring, and preservatives
   • Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, insulin, morphine, ACE inhibitors, or antibiotics
   • Chemicals found in man-made objects, such as rubber materials.
   • Insect bites, flying animal stings, dust mites, and wool.
   • Plants with itchy hair, such as poison ivy, pollen, and nettles
   • Plant rubber, fruit resins such as latex, banana resin, mango resin, 
   • Kiwi allergy, chestnut allergy
   • Certain cosmetics
   • Some diseases, such as thyroid disease, lupus, pharyngitis, tonsillitis, and some types of cancer, COVID-19
   • Infections in the body such as viruses, bacteria, fungi, or parasites
   • Weather, temperature changes, exposure to hot or cold weather, sunlight, UV rays, sweat.
   • Tight clothing or a belt, skin friction
   • Contrast media used in radiology, such as CT scans or MRIs.
   • Stress, anxiety
   • Inadequate sleep, low body immunity.

What are the symptoms of urticaria (hives)?

Urticaria (hives) symptoms and severity vary depending on the source of the allergy and how an individual reacts to the allergen. Urticaria symptoms include the following:

• Raised patches, swollen welts, varying in size, ranging unevenly from small to large; 0.5-10 cm, with clear distinct edges and no flaking.
• Red or pink welts that become pale when pressed are distributed throughout the body or are in specific areas.
• Very itchy rashes with irritation and burning pain.
• Rashes that occur and disappear on their own within 24 hours.
• On-and-off rashes occur 2-3 times a week for months.
• Itchy rashes occur upon exposure to hot or cold weather, sunlight, sweat, exercise, or stress.

Severe acute urticaria symptoms include:

• Urticaria rashes spread rapidly throughout the body, including the arms, legs, face, around the eyes, and mouth.
• Swollen face, lips, and eyes, similar to angioedema. 
• Respiratory symptoms such as airway obstruction, asthma, nasal congestion, and shortness of breath.
• Cardiovascular symptoms such as chest tightness and low blood pressure
• Gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea
• Dizziness that feels like fainting, fever, and joint pain throughout the body

How is urticaria diagnosed?

The doctor will take your medical history and perform a physical examination to assess symptoms, gauge the severity of the allergic reaction, and inquire about exposure to allergens such as food, drugs, poisonous animal stings, latex, plant pollen, or other chemicals that may cause urticaria. In addition, the doctor may order additional diagnostic tests to identify the cause of the allergy with the following methods:

1. Skin Prick Test (Allergy Skin Test) is a skin test that involves dropping allergen protein extracts onto the skin and pricking the skin with a needle into the middle of the droplet to observe the allergic reaction. An itchy wheal will appear on the skin if there is an allergic reaction. The test can provide results within 20 minutes, with minimal risk of rash on other parts of the body.
2. Allergy blood test (Specific IgE test) is a blood test that measures the amount of allergen-specific immunoglobulin E (IgE) the body excretes by the immune cells to fight against allergens. A high level of IgE against the allergen means there has been previous exposure to allergens that incite urticaria. The allergy blood test result is typically available in 2-3 days.

How are urticaria treated?

Urticaria typically resolves on its own without the need for treatment. A thorough diagnosis by a doctor to check for symptoms and get medication is preferable, as medications help relieve itching and help the urticaria rashes collapse faster. The doctor will consider treatment options as follows:

• Antihistamines help to relieve the severity of itching, swelling, and other allergy symptoms.
• Allergen immunotherapy: In those with chronic urticaria, the doctor may consider allergen desensitization to suppress the excessive secretion of IgE antibodies to relieve symptoms, reduce urticaria, and decrease itching.
• Immunosuppressant: If the symptoms do not improve, or chronic urticaria does not respond to antihistamines, the doctor may prescribe an immunosuppressant to help the rash heal faster.
• Anti-inflammatory medications: For those with severe urticaria or angioedema, the doctor may prescribe corticosteroids—an oral medication to reduce swelling, inflammation, and itching.
• Biologics: These drugs help reduce the irregular secretion of IgE antibodies, but do not suppress the immune system. Doctors prescribed biologics only in those with chronic urticaria.
• Hereditary angioedema drugs: To treat hereditary angioedema with swelling under the skin, epithelium of the upper airway, and gastrointestinal tract, the doctor prescribes specific medications to prevent and relieve symptoms since the antihistamines, epinephrine, and steroids have little effect in alleviating swelling of hereditary angioedema.

What is the at-home first-aid treatment for urticaria?

Mild urticaria can be relieved at home with the following home remedies:

• Take an over-the-counter antihistamine such as a non-sedating antihistamine.
• Topical ointments such as topical steroids
• Take a cold shower or apply cold compresses to relieve itching.

What are the complications of urticaria?

Urticaria complications may include the following symptoms:

• Angioedema is a severe swelling of the subcutaneous tissue that can cause swelling of the face, throat, and upper airway obstruction, which can be life-threatening.
• Anaphylaxis is a severe allergic reaction triggered by exposure to certain allergens in susceptible individuals, such as medications, foods, and animal stings, causing shortness of breath, chest tightness, hypotension, and a rapid heartbeat, which require immediate EpiPen administration.

What is the prevention of urticaria?

: Observe, avoid and stay away from contact with sources of known allergens such as food, medications, pollen, heat, stress, or allergenic materials.

• Wear loose clothing, avoid tight clothing and rough fabric clothing that may rub the skin, and avoid wearing fur clothing.
• Avoid being in hot or cold temperatures; avoid being in the sun; and use sunscreen when going out in direct sunlight.
• Do not scratch the itchy rashes to prevent dermatitis and stimulate the spread of the rash.
• Having a skin prick test or blood allergy test
• Get enough sleep; avoid stress and anxiety.

What are the symptoms of night urticaria?

Night urticaria is due to allergen exposure near bedtime, such as certain bedtime medications, allergens in clothing and bedding, or temperature changes in the room. Furthermore, evidence suggests that mast cells respond to circadian rhythm; as a result, mast cells release more histamines, exacerbating the inflammation that causes swelling and itching during the night.

How long does urticaria last?

Acute urticaria usually goes away on its own within 2-3 days to 2-3 weeks. However, chronic urticaria that persists over 6 months may take more than a year to resolve.

Urticaria, an allergic reaction treatable at its cause

Urticaria are itchy skin welts that affect daily life. While antihistamines can manage acute urticaria, finding the underlying cause leads to a complete cure. Untreated urticaria can progress into chronic urticaria, which has a long-term impact on one's life. Those experiencing severe acute allergic reactions, such as chest tightness, wheezing, and shortness of breath, should be taken to the hospital as soon as possible for treatment to prevent shock, loss of consciousness, and death. Therefore, those experiencing any type of urticaria should have a thorough physical examination to identify allergens and triggers and receive desensitization therapy to prevent future recurrences of urticaria.