Physicians arbitrarily divide hives into acute (new or periodic episodes lasting fewer than 6 weeks) and chronic (periodic episodes lasting more than 6 weeks). Though many people have a single episode of acute hives that goes away within a few days to weeks, some individuals may have chronic hives, periodic (recurrent) attacks of hives that come over periods of years.
Hives can be triggered by many things, including:
- Medications, especially aspirin, ibuprofen, naproxen, narcotic painkillers, or antibiotics
- Infections with viruses, bacteria, or fungi
- Environmental allergies such as insect bites, pollen, mold, or animal dander
- Physical exposures such as heat, cold, water, sunlight, or pressure
- A medical condition such as gland diseases, blood diseases, or cancer
- Food allergies, such as strawberries, eggs, nuts, or shellfish
Acute hives are most common in children and young adults, and chronic hives are more often seen in females, especially middle-aged women.
Hives are very common; it is estimated that up to 20% of the population may develop hives at some point in their lives.
- Upper arms or upper legs
Individual lesions of hives appear as distinct (well-defined), pink-to-red swellings ranging in size from 2 mm to over 30 cm. Some lesions may develop a lighter center. Hives usually appear in groups or batches.
Individual lesions of hives disappear within 24 hours, though a single episode may last much longer.
Dermographism is a type of hives that appears within a few minutes of scratching the skin. The rash usually appears in a straight line (linear) pattern.
Swelling of the eyes, mouth, hands, feet, or genitals can sometimes occur with hives. This swelling, called angioedema, usually goes away within 24 hours.
Hives is usually an itchy rash that can also burn or sting.
- Take cool showers
- Apply cool compresses
- Wear loose-fitting clothes
- Avoid strenuous activity
- Use an over-the-counter antihistamine such as diphenhydramine or loratadine
In other, non-urgent, situations, see your child's doctor if the hives do not improve with treatment or if they continue to appear for more than a few days.
Before visiting your doctor, try to notice what might be triggering your child's hives and whether it improves or worsens with exposure to heat, cold, pressure, or vibration. Take a list of every medication (prescription or over-the-counter), supplement, or herbal remedy your child may have taken recently. Also, recall any recent illnesses your child might have had, since some illnesses (or their treatments) can trigger hives.
Obviously, the best treatment for hives is to discover any triggers and stop your child's exposure to them. However, most people with hives do not know the cause, and they require medications to get rid of the hives.
The most common medications for hives include:
- Sleep-causing (sedating) type-1 antihistamines such as diphenhydramine, hydroxyzine, or cetirizine
- Non-sleep-causing (non-sedating) type-1 antihistamines such as loratadine, fexofenadine, or desloratadine
- Type-2 antihistamines such as anitidine, cimetidine, or famotidine
- Montelukast, zafirlukast, or zileuton