Heat and mottled skin

[HeartsOpenWide, RN]

Why would heat (like sitting in front of a heater) cause mottled skin? Wouldn't it seem like it would cause the skin to be red?

[Crux1024]

Found online:

Patchy skin color refers to areas of irregular skin coloring. Mottling or mottled skin refers specifically to blood vessel changes in the skin which cause a patchy appearance.

Irregular or patchy discoloration of the skin can be caused by:

• Changes in melanin, a substance produced in the skin cells that gives skin its color
  
• Growth of foreign organisms on the skin
  
• Blood vessel (vascular) changes
  

The following can increase or decrease melanin production:

• Your genes
  
• Heat
  
• Injury
  
• Exposure to solar or ionizing radiation
  
• Exposure to heavy metals
  
• Changes in hormone levels
  

This is a good question. I actually caused an area of mottled skin on my own face while I in need of a root canal. The pain got so bad, I left heat on my face all night and when I woke up the next morning, my cheek/jaw line were purple and mottled. Thankfully, its faded since then and is practically unnoticable.

[caliotter3]

I got some permanently mottled skin that appeared on the arm that was receiving an iron infusion, when I was severely anemic and had to have blood transfusions. Oddly enough, the area grew a long time after any affects from the infusion should have had any effect. I showed it to the doctor when it first appeared in the hospital. I assumed the connection, the doctor didn't/or couldn't say.