Hives occur when fluid from your blood vessels and capillaries becomes trapped underneath your skin, causing localized swelling and redness. Hives can be large or small and resemble mosquito bites. An individual with hives may also experiences itching and significant discomfort. There are different causes for hives, so if you can isolate the cause of your hives, you can attempt to avoid future breakouts.
Allergies are a common cause of hives since an allergic reaction can trigger the immune system response that results in trapped fluid beneath the skin. An allergic reaction can occur due to something you ingested or were exposed to through the air. Pollen, pets, food products and medication are all common allergies that may result in hives. Although most individuals can treat an allergic reaction at home with an over the counter antihistamine, a severe case of hives may require a visit to the doctor.
According to Dr. Clifton Bingham, a medical professor at Johns Hopkins University, viral infections, such as the common cold, are the cause of approximately 80 percent of all cases of hives in children. The hives usually appear as the individual starts to recover and may last up to two weeks before subsiding. Herpes, hepatitis B and Strep have also been known to trigger hives breakouts.
In some cases, hives can be the body's response to cold temperatures. Known as "cold uticaria," this condition may signify the presence of another underlying disorder. Cold uticaria can manifest immediately or 24 to 48 hours after exposure. Young adults between age 18 and 25 are more likely to break out in hives due to extreme cold than any other age group. Your physician can run a cold-stimulation test to determine if you suffer from cold uticaria.
Some cases of hives can be attributed to the body's sensitivity to clothing or jewelry that fits too tightly against the skin. This can trigger the body's histamine response and result in hives. If any pressure at all causes you to break out in hives, however, you may suffer from a condition known as "dermatographia." According to the National Institutes of Health, dermatographia is harmless, but even the slightest touch can cause the skin of dermatographia suffers to break out in hives
Stress and Anxiety
Some hives sufferers claim that stress and anxiety trigger their outbreaks. While stress and anxiety may precede an attack of hives, they do not directly cause the body's histamine response. What stress does do, however, is reduce the effectiveness of the body's immune system. This can result in individuals who do not normally suffer from hives to break out seemingly at random. While a strong immune system can prevent hives from occurring, an immune system that has been weakened due to stress may be unable to prevent a physical reaction to stimuli that cause hives.