Strange Red Spot On Child's Skin

[luv2bamom117]

My 6 year old son recently developed a strange spot just above his knee.  It started out looking just like a blood blister.  Then it changed to more of a hemangioma birthmark looking spot, just slightly larger than a normal blood blister.  Then it changed from red back to flesh color (but still slightly raised and bumpy looking) and I thought it was going away, but now it turned back to the red color again.  He says it doesn't hurt/itch and doesn't recall getting pinched or anything on his knee that might have caused it.  Any ideas of what this might be?  Should I have it checked out?

Thanks!

[Dr_Aparna]

Hi,
Blood blisters are a type of blister that is filled with blood rather than the fluid commonly associated with blisters. Blood blisters are caused by a rupture of the blood vessels underneath the skin’s surface. This rupture is usually caused by some form of trauma, such as pinching.
A person may also develop bloodbloodblood blisters after being scalded or burned, including from sunburn. Blood blisters can also develop in response to allergic irritants, viral skin infections, and fungal skin infections.
ref:http://www.wisegeek.com/what-causes-blood-blisters.htm
If the blister breaks, quickly rinse the area and apply an antiseptic such as neosporin. It is not recommended to break a blister because it may lead to infection.Otherrwise no treatment is required.
If it persists for longer than a wekk to 10 days or if it re-appears else-wher on the body it needs to be further evaluated.

[luv2bamom117]

He's definitely had it for more than a week.  Now today it turned from red to almost bluish-black.  It no longer looks like a blister, but like one of those hemangioma birthmarks.  It has't changed size at all but it has changed to different colors now a couple times and is several small bumps all clustered together instead of one blister looking spot.  It has simply stayed in the same spot.

[luv2bamom117]

I recently read how Sole, a solution of crystal salt and water, is really good for skin troubles.  For about a week now, I've been dabbing some sole onto the spot and it is almost gone.  The first day, it was dramatically better.  The red color is gone and the bump is almost completely gone!