Kim, who once worked as Paris' assistant before she too became a TV star, has appeared in photos and videos, celebrating with Hilton, from the bash, which went down at Club Paris - a nightclub created in the birthday girl's home.
"Love you @KimKardashian So much fun celebrating my birthday with you at #ClubParis," Paris, who actually turned 38 on 17 February, captioned the video.
"Happy birthday, Paris... even though your birthday was... months ago, this is how she celebrates," Kim said in the clip. "Months... months and months. But she deserves it."
Following the party, Kim woke up on Sunday morning to a psoriasis breakout all over her face.
The all-too-real 38-year-old "Keeping Up with the Kardashians" star shared a selfie of her face full of red patches on her Instagram Story account.
"Morning psoriasis," she captioned the picture of herself in bed.
Kim has never shied away from the skin condition since going public with her daily battle back in 2011, and she has updated fans over the years. Last month, she showcased a herbal ointment she was using to keep flare-ups on her face to a minimum.