Johns was diagnosed as having reactive arthritis late last year. The condition’s primary symptoms are chronic swelling of the joints, resulting in impaired movement and extreme pain, thus making it difficult for Johns to fulfill his duties as singer and guitarist in the band.

“I am truly sorry that I am not able to do the touring we had planned for so long,” said Johns. “I apologize for the inconvenience these cancellations will cause. I am doing everything humanly possible to try and get well, but lately things have just kept getting worse.”

While all shows have been canceled, Johns is expected to be able to perform some limited promotion duties for their new album, Diorama. However, doctors specifically ruled out all travel and have placed Johns on a strict treatment regimen.

In the majority of reactive arthritis cases, the condition only lasts for three or so months. However, new medical tests have revealed underlying complications which appear to be preventing Johns from fighting off the virus that triggers this form of arthritis.

His doctors remain certain that the condition is not life-threatening and that he will eventually make a full recovery.

Silverchair had plans of touring in support of Diorama, which will be released in the States at the end of July. Performances had been scheduled in the States, U.K., Canada and Europe throughout the summer.