degeneration skills

i play a r/mes and i've been getting hit hard by degneration in the arenas. mes/eles or ranger/necs r usually i think the culprits. is there anything i can do about this? troll unguent doesnt seem to act fast enough to counter this. also, do degeneration spells/attacks stack? for example say poison arrow combined with conjure phantasm? thanks for any help.

Poison is -4 degen
Conjure Phantasm is -5
Stacks to -9.

On the other hand adding in bleeding which is -3 to that would only partially stack to 10 due to the cap.

Degen is easily fixed by a monk; you're in arenas though so that is a problem.