The 28-year-old prankster mocked-up telly star Louise without any hair using a Snapchat filter.
Fan Emma Archer, who has had alopecia for over 20 years, was left feeling offended after seeing the post.
Sam s video post - which racked up 62,000 views - was later removed but married mother-of-two Emma claims he then mocked her in a string of direct messages.
Emma - who lost 80 per cent of her hair at the height of her alopecia - said: All I wanted was him to say Sorry it was never meant to be offensive .
Made in Chelsea star Sam Thompson (left) has been slammed by an alopecia sufferer over a post in which he made his co-star sister (right) bald