Pop star Avril Lavigne has apologised to fans for cancelling a concert in San Diego, California after she was struck down with laryngitis.

The Sk8ter Boi hitmaker, whose U.s. tour has been plagued by poor ticket sales, called in sick ahead of the show at Cox Arena on Wednesday evening.

Fans were left fuming, insisting the singer didn't give them enough notice of the cancellation as many had already made the journey to the venue by the time the news broke.

Lavigne has subsequently cancelled appearances on U.s. TV show Tonight With Jay Leno and on Ryan Seacrest's Los Angeles radio show - citing ill health.

And she has now issued a statement on her website, apologising to fans for the scrapped gig.

She says, "I am at home right now taking it easy. I have been sick this whole tour, and now I have lost my voice. I have never canceled a show in my whole career and just had to for the first time ever. This sux (sic)!"

"I just played 4 shows in a row in Texas (which is a lot for the vocals) and woke up in Vegas Tuesday with no voice. I thought I was gonna have to cancel that show, but I made it through?..barely! I woke up yesterday and knew I wouldn't be able to sing last night. My voice is so shot."