Hives, or urticaria, are itchy, raised welts on the skin that can vary in size and colour. Their duration varies from a few hours to several days, but in some cases, they can last for weeks or even months. Factors such as the underlying cause, individual immune response, and treatment effectiveness influence the length of a hive episode. Managing hives requires understanding their timeline and finding relief from the uncomfortable symptoms they bring.
What Are Hives?
Hives, also known as urticaria, are red raised bumps or welts that appear on the skin. They are a common skin reaction often triggered by allergens. These spots can manifest as small dots, patches, or interconnected bumps and can occur anywhere on the body. The duration of individual hives can range from a few hours to a week, sometimes even longer. As fading hives may be replaced by new ones, those lasting for up to 6 weeks are categorized as acute hives, while those persisting beyond 6 weeks are classified as chronic hives.
What Causes of Hives?
Hives can be triggered by allergies, as well as:
- Extreme temperatures
- Certain illnesses
In certain instances, individuals may experience hives along with angioedema, which involves swelling around the eyes, lips, hands, feet, or throat. Although rare, hives and angioedema can be associated with a severe allergic reaction affecting the entire body, known as anaphylactic shock.
Hives occur when mast cells in the bloodstream release histamine, causing tiny blood vessels under the skin to leak and form red welts. This can happen due to various reasons, and often the cause remains unknown.
Allergic reactions are frequently associated with hives, causing rapid skin breakouts. Common allergens include:
- Foods, particularly shellfish, peanuts, tree nuts, milk, and certain fruits.
- Medications, including antibiotics and allergy shots.
- Pets and other animals.
- Insect bites and stings.
Hives can occur without any allergic causes and may be triggered by various factors such as:
- Infections, including viral infections.
- Physical stimuli like exercise, anxiety, stress, sun exposure, cold temperatures (cold water or snow), chemical exposure, scratching (dermatographia), or pressure on the skin (from sitting for too long or carrying a heavy backpack over a shoulder).
Hives caused by physical factors like pressure, cold, or sun exposure are known as physical hives.
Determining the cause of chronic urticaria can be challenging, although it is sometimes associated with immune system disorders like lupus. In other cases, medications, food, insects, or infections can trigger hives. However, frequently the underlying cause of chronic hives remains unknown to doctors.
Signs & Symptoms of Hives
The main characteristic of hives is the presence of red raised welts, which can exhibit the following features:
- They may have a pale centre.
- The welts can appear in clusters.
- They have the ability to change shape and location within a short period, sometimes even within hours.
- They can vary in size, ranging from tiny spots to as large as a dinner plate.
- Hives often cause itching, stinging, or a burning sensation.
In addition to hives, individuals experiencing angioedema might also have symptoms such as puffiness, blotchy redness, swelling, or large bumps around the eyes, lips, hands, feet, genitals, or throat. Other associated symptoms can include nausea, vomiting, or abdominal pain.
While rare, a person with hives and angioedema may also develop anaphylactic shock. Signs of anaphylactic shock include difficulty breathing, a drop in blood pressure, dizziness, or loss of consciousness (fainting).
In most cases, doctors can diagnose hives by visually examining the skin. To determine the underlying cause, they may inquire about your child’s medical history, recent illnesses, medications, exposure to allergens, and daily stress levels.
For chronic hives, the doctor may request that you maintain a daily record of activities, including your child’s diet, beverages consumed, and the locations where hives tend to appear on the body. Diagnostic tests, such as blood tests, allergy tests, and screenings to rule out conditions like thyroid disease or hepatitis that can cause hives, may be conducted to pinpoint the exact cause.
In the case of physical hives, a doctor might perform a cold test by applying ice to your child’s skin to observe its reaction, or they may apply pressure using a sandbag or another heavy object on the thighs to determine if hives are triggered.
In many instances, mild hives will resolve on their own without the need for treatment. If a specific trigger is identified, avoiding it becomes a crucial part of the treatment plan. In cases where hives cause itchiness, the doctor may recommend the use of antihistamine medication to block the release of histamine in the bloodstream and prevent further outbreaks.
For chronic hives, the doctor might suggest a non-sedating antihistamine, available either as a prescription or over-the-counter, to be taken daily. However, since not all individuals respond equally to the same medications, it is essential to collaborate with the doctor to find the most suitable one for your child.
If a non-drowsy antihistamine proves ineffective, the doctor may propose a stronger antihistamine, an alternative medication, or a combination of treatments. In rare cases, a doctor may prescribe a short-term course (5 days to 2 weeks) of oral steroids to manage chronic hives. This approach is used cautiously to minimize the potential side effects associated with long-term steroid use.
Q1: What are the common triggers for hives?
Ans: Allergies, stress, infections, temperature extremes, chemicals.
Q2: How long do hives usually last?
Ans: Duration varies from a few hours to weeks or months.
Q3: How can hives be diagnosed?
Ans: Through visual examination and medical history assessment.
Q4: What treatments are available for hives?
Ans: Antihistamines, avoidance of triggers, and in some cases, steroids.
Q5: What is the difference between acute and chronic hives?
Ans: Acute hives last up to 6 weeks, while chronic hives persist beyond 6 weeks.