"Heat rash" turns into cellulitis

vln, I'm so sorry! Several things going on all at once here, so maybe we can sort them out and see what ideas others will come up with.

First, cellulitis causes are sometimes difficult (or impossible!) to pin down. Micro-breaks in the skin can allow bacteria to enter, so it's important to consider whether the soap and lotion you're using is doing enough to keep your skin soft and supple.

Repetitive motion (violin playing, for instance) can aggravate LE and that makes infection more likely from whatever small cause (even a hangnail, insect bite, paper cut). Chafing can be a problem. Maybe Nordy will come along and tell us what marathoners do to avoid chafing their arms as the run (I think it has something to do with Vaseline, but I wouldn't swear by it. Oh, Nooooooordy!) If it's something like that, be sure to wash it off well afterward and again apply your regular lotion.

Keeping cool when dressed to the nines for a concert is a challenge, for sure. Here's a cooling vest we were discussing recently. It's less bulky than others and the cooling effect lasts a long time -- probably as long as that marathon rehearsal:
http://www.activemsers.org/gear/reviewcoolingvest.html
You can also get small cleavage coolers (I'm not making this up) that you place in your bra. The theory is they cool your chest, thereby sending cooler blood coursing through your veins. I have no idea whether that's true or not, but they are refreshing and actually work fairly well. Here's an example:
http://www.cleavagecoolers.com/A-Wardrobe-Basics-2299-BW.htm

Finally, since staying infection-free is going to be an important aspect of continuing in your career, you might ask your doctors if a referral to an infectious disease specialist would be in order to help you track down any other risk factors. If you go that route, make sure the one you see is familiar with LE.

Rest up, feel better, heal up fast! You must feel sorta conflicted about Beethoven at this point, but I hope you and he will be able to come to a mutually healthy regard for one another again-- play on!

Gentle hugs,
Binney

For anti chafing, try BodyGlide anti-blister & Chafing balm. Sport people use this.

I use it for my inside elbow and it is pretty good all though I am still super sensitive. I wrote the company to see if it was compatible with the sleeve material and they said yes, they have customers using it with compression garments.  

You can use it also on your heel area if you have a pair of shoes that want to make a blister.