What Are Hives?

A close-up of my shin (right under my knee) in 2012

A close-up of my shin (right under my knee) in 2012

Hives are something I've heard about since I was little. While it's nothing new to me, I never really researched exactly what it was. My skin has had so many different types of allergic reactions that I figured some were definitely hives at some point.

Turns out, that's exactly what I had above in the photo! There's one quarter sized welt right below my knee.

Hives are also known as wheals or urticaria. About 20% of the population experience hives in their lifetime - women are twice as likely. So what are they exactly? Hives are a skin reaction that result in spongy welts that can be red, white or the color of your skin. It can spread and is capable of happening pretty much anywhere on your body. Hives do tend to avoid the palms of hands and the bottoms of feet, though.

This skin reaction can be:

  • itchy
  • painful
  • different shapes:
    • round
    • ring shaped
    • random shape
  • different sizes from a couple spots to large blotches
  • fading in and out throughout the reaction

"About Health" does a great job explaining exactly why hives occur:

Hives result from dilation of capillaries allowing fluid to leak out into the surrounding tissue, the epidermis. They resolve when the body absorbs this fluid. The border of a hive is described as polycyclic, or made up of many circles, and changes as fluid leaks out and then is absorbed. Pressing on a hive causes the skin to blanch distinguishing it from a bruise or papule.
— http://dermatology.about.com/cs/hives/a/hives.htm

The thing about hives is that they can happen for a large variety of reasons... that's exactly why some people never figure out the root of their problem. I believe that any hives I've had are a result of allergies or water. I have so many skin allergies that it only makes sense that some of my hives have been from allergies. And I often get hives fresh out of the shower. There must be something about what's in the water or the heat of the water.

Possible causes/triggers of hives:

  • allergies (the most common)
  • thyroid disease
  • lupus
  • hay fever
  • pain medication
  • infection
  • scratching
  • excessive heat or cold
  • stress
  • sunlight
  • exercise / sweating
  • animal dander
  • pollen
  • alcohol
  • food
  • preservatives / additives
  • prolonged pressure on the skin
  • high humidity

Treatment:

  • antihistamine
  • avoiding hot water
  • avoid aggravating the affected area
  • a doctor may prescribe an epi-pen or steroids

While in most cases, hives disappear on their own and are considered harmless, they can also be a sign of something more serious. If your throat starts to swell or the hives last more than 48 hours, it's advised that you seek a doctor.

 

Sources:

http://www.mayoclinic.org/diseases-conditions/chronic-hives/basics/causes/con-20031634

http://www.mayoclinic.org/diseases-conditions/hives-and-angioedema/basics/definition/con-20014815

http://www.healthline.com/health/hives#Overview1

http://www.medicalnewstoday.com/articles/157260.php

http://dermatology.about.com/cs/hives/a/hives.htm