Cellulites

I have just returned home from the hospital following an infection in my lymphedema arm. I have no idea how I got the infection. There was no puncture, or bite, I hadn't even overdone the use of the arm. I had the surgery in '93 and this is the first time I've had an infection. I have tried to treat the arm using a pump and then manual massage and drainage, but neither really gives a satisfactory result, for long, anyway. I am now worried that I may have recurring infections and am wondering what, if anything, I can do to prevent this. I'd sure appreciate any help anyone can give. Perphaps someone can shed some light on the possilbe cause of the infection. I do not relish another week in the hospital.