Diagnostic problems can arise in people suffering from psoriatic arthritis.
This is the view of David Chandler, chief executive of the Psoriasis and Psoriatic Arthritis Alliance.
Mr Chandler added that the condition can also be a problem in terms of employment, since employers "aren't always sympathetic to a condition which one day appears not to affect the individual and the next day means they can barely walk".
Psoriatic arthritis is a condition which often affects individuals who have the skin disorder psoriasis.
Approximately ten to 20 per cent of people with psoriasis will go on to develop the problem, which is characterised by swollen, tender or painful joints.
However, Mr Chandler said that the condition can be "managed and controlled".
Despite this, the person will still face difficulties for "365 days a year with no days off, just degrees of severity".
"Some days are OK, but others can be a complete wipe out," he added.
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