Welcome to the forum tattie
The symptoms of minocycline induced lupus are the same as those of lupus except it is unusual to have organ damage. Blood test results are the same too. Symptoms and test results can vary as they can in lupus.
It might be hard to tell the difference between drug induced disease or clinical 'real' disease. Sometimes the only way to tell is when the symptoms go after the implicated drug is stopped. The absolute proof is if the symptoms return when the drug is started again.
Same treatment as necessary, as true lupus but usually NSAIDs are enough for the arthritis.
Full check up is needed because minocycline can have other possible hidden side effects, liver disease I think for example
Good Luck
Clare