Alexis tells us her cartilage ear piercing had been giving her grief since she got it a year ago ... but it wasn't until a hairdresser accidentally bumped into it last Thursday that she really felt the agony. Ouch!

She says her hairdresser notified her that the earring was deeply embedded in her ear, and the skin around it was clearly infected and overgrown. Alexis didn't waste any time and dashed straight to urgent care to get it sorted out. Smart move!

However, when docs busted out the scalpel, Alexis told them to hold up ... 'cause the only person she'd trust near her ear was Terry. Of course, the "Botched" star's wife, Heather Dubrow is Alexis' costar on 'RHOC,' so it's all about keeping it all in the Bravo family.

The big removal went down Monday, and Dr. Dubrow, being the champ he is, even skipped his lunch break to help her out.

We're told he managed to pull out Alexis' earring, which was decked out with four diamonds, without having to make any incisions. Now that takes some serious skill.

For his part, Terry tells TMZ he's glad Alexis came to him for help ... especially 'cause messing with infected cartilage in your ear is like playing with fire. He explains to us the area doesn't have much blood flow, so if things go south, it can result in seriously gnarly infections that can straight-up wreck your ear, or even worse. Yeah, no thanks!

Alexis is showering Terry with gratitude ... telling us he's a top-notch surgeon and a super kind friend. She's also raving about how Terry squeezed her into his busy schedule ASAP and made sure the whole ordeal was as painless as possible. Now that's the definition of having a true friend in high places!