Seems to be different things being described here. Golfers vasculitis is an internal issue. There is nothing you can put on it. It usually doesn't hurt or itch. It occurs in a certain group of people...the four Fs...female, 50+, fair, and fat..I take issue with the fat. You don't have to be fat, but it can happen if you are just a bit overweight!
I had it horribly every time I went to WDW from April through October. Heat and humidity are a huge issue for this. Add the fact that you're on your feet more than usual? Perfect storm. As soon as I got home and off my feet, and cooler, it went away within 2 days!
So...I asked my doctor about it. She said it was probably a rash from eczema or psoriasis. No, don't think so. I took a photo of it the next year. She said the same thing, and showed it to the other doctors in the practice. Same response. I knew that wasn't the answer, so I went online. I found out all about vasculitis! I printed out the info and brought it to my next appt. my doctor looked at, gasped, and brought my records up. Seems that a blood pressure med I was on, for the previous 5 years, exacerbated the vasculitis! She was horrified that they had all missed the vasculitis to begin with. Well, long story short, my b/p med was changed. Since then, I've had a much milder 'attack'. I probably wouldn't even notice it if I wasn't looking for it. But it was so bad to begin with that people would stop and stare. I looked like I had something really awful, like leprosy!
Just about the only thing you can do is to use cool compresses and elevate your legs. Time in a cool pool helps too.