Lindsay Lohan is shockingly skinny again - mere days after her traumatic break-up with Samantha Ronson.

The "Mean Girls" star showed off rail-thin arms and a protruding rib cage as she went shopping with her kid sis Ali in Los Angeles on Tuesday.

More pics after the jump

Lohan later covered up her teeny frame under a baggy shirt while hitting a party that evening.

The 22-year-old's weight appears to have dipped down to the diminutive figure that shocked fans in 2005. Lohan later admitted to Vanity Fair that her weight had gotten out of control during that time.

"I knew I had a problem and I couldn't admit it," the singer-actress told the mag in early 2006. "My arms were disgusting. I had no arms."

Lohan also said she was "making myself sick" at the time - a claim she later said was "misconstrued."

Lohan recently told Us Weekly that she feels "so alone" after her early April split from Ronson, her girlfriend of a year.

"I'm a f--king 22-year-old girl who's in love," she said. "I'm just really hurt. This whole situation is sick."

But her love life isn't the only thing that isn't going well for the starlet. Lohan's upcoming comedy "Labor Pains" is headed to TV - then DVD - and the actress recently complained to E! News that "sicko fans" are keeping her from getting work.