Why do hives break out?

Fact Checked

Hives manifest once fluid from the blood vessels and capillaries are trapped under the skin which results to localized redness and swelling. The hives can be large in size and strikingly resemble mosquito bites. An individual who develops hives might also suffer from itchiness and significant discomfort. There are various causes for hives, thus if the exact cause of the hives is isolated, the individual can avoid future breakouts.


Allergies are considered as the common cause of hives since an allergic reaction can instigate an immune system response that leads to trapped fluids under the skin. In most cases, an allergic reaction can manifest due to certain foods ingested or exposed to the air.

Pets, pollen, medications and food products are the common allergies that can trigger the manifestation of hives. Even though many individuals can treat an allergic reaction at home with an over-the-counter antihistamine, a severe case might require proper assessment by a doctor.

In some circumstances, hives is a response of the body upon exposure to cold temperatures.

Extreme cold

In some circumstances, hives is a response of the body upon exposure to cold temperatures. This is also called as “cold urticaria” which indicates the possibility of another underlying health condition.

Cold urticaria can develop right away or after 24-48 hours after the exposure. In most cases, young adults in between 18-25 years are more likely to experience a break out of hives upon exposure to extreme cold than any other age group. The doctor might perform a cold-stimulation test in order to determine if he/she is suffering from this type of urticaria.


It is important to note that viral infections such as the common cold can be considered as the cause of some cases of hives outbreak among children. The hives typically manifest as the individual starts to recover and can last for up to 2 weeks before subsiding. Hepatitis B, herpes and strep are also known to instigate breakouts of hives.


Some cases of hives outbreak can be linked to the sensitivity of the body to jewelry or clothing that fits too tightly against the skin. Remember that this can trigger the histamine response of the body and cause the breakout of hives.

In case any pressure starts a break out of hives, there is a possibility that the individual has dermatographia. This is considered harmless but even a slight touch on the skin among those who have the condition can lead to an outbreak of hives.

Stress and anxiety

Some individuals who suffer from hives claim that anxiety and stress can trigger outbreaks. Even though stress and anxiety can precede an outbreak of hives, they do not directly trigger the histamine response in the body. Stress simply reduces the effectiveness of the immune system.

As a result, individuals who do not normally suffer from hives end up with random breakouts. Even though a strong immune system can prevent the development of hives, an immune system that is weak due to stress could not effectively prevent a physical reaction to stimuli that instigates hives.

Was this post helpful?

Leave a Comment

Your email address will not be published. Required fields are marked *

Shopping Cart
Scroll to Top

  • All stmarkjamestraining.ca content is reviewed by a medical professional and / sourced to ensure as much factual accuracy as possible.

  • We have strict sourcing guidelines and only link to reputable websites, academic research institutions and medical articles.

  • If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please contact us through our contact us page.

The information posted on this page is for educational purposes only.
If you need medical advice or help with a diagnosis contact a medical professional