Is External Application Of Voltaran Cream Safe For Inflammation Around The Knee?

A few years back, I had a reaction to taking aspirin.....Today, my orthopedic Dr prescribed Voltaran creme for imflammation around the knee area....I reminded her about the aspirin reaction and she said it's a low dose and since it's not being taking orally, it should be ok. What are your thoughts on this? I feel reluctant to taking it.