This has happened to me several times now. What the heck causes it???
I'm going about life as usual when I feel a sudden itch somewhere on my thigh, under my clothes. Really sudden, almost painful in its intensity. So I scratch it. A moment later it itches again. After about the third scratching, I start to wonder what's up (and resist scratching, with gritted teeth!), and when I get my clothes off I find an area about 2"x3" (the area I scratched) covered with small bright red dots. Very soon they get larger and turn purple. It doesn't spread much beyond the original area, but the dots blur into each other. Sometimes it swells just a little. Putting ice on it right away reduces the purpleness and swelling.
Once I've resisted scratching
: for about half an hour, it stops itching. The dots heal slowly over several days.
It looks to me like my scratching is breaking a lot of capillaries under the skin, causing a cluster of tiny bruises. What I don't understand is why my capillaries would be so weak. I mean, I scratch myself that hard pretty often without any sign of this, but this particular type of itch makes these dots cover the whole area all of a sudden. Once I'm paying attention to the "character" of the itching, after I've realized what the problem is, it feels different than the itching of a mosquito bite or poison ivy; it's like something suddenly crawling or dripping on the inside of my skin.
I have low blood pressure, if that means anything. I sometimes wear compression stockings and have never had this happen with them on.
I don't think this is contact dermatitis because it's always happened to one small area of my skin that had not been treated differently than the surrounding area and had been covered for hours. It's never happened at times when I've been rolling in the grass or anything unusual.
It's always on my thigh but not always in the same place--anywhere from near the hip to just above the knee.
Incidents are months apart usually. Once it happened in a different spot about 12 hours after the first.
Please help! I tried to look it up online, but the only similar things I found were symptoms of rapidly fatal diseases!