WTF is that? It’s Sarah Jessica Parkers arm!

Looking at the photo up-close, we had no idea what it was – turns out it’s Sarah Jessica Parkers arm!

The Sex and the City actress was spotted with her mega-skinny arms on show – and displaying veins that even Madonna would be proud of.

Sarah was papped outside her home in New York wearing a sleeveless top, and maybe it was because she was carrying something heavy, but her arms definitely look weird.

Click here for a photo.