NSAIDs are conditionally recommended for pain relief in peripheral arthritis. Caution should be exercised for their side effects which include GI upset, hypertension and renal dysfunction.

Corticosteroids can also be used either as a brief course of oral systemic steroids, intramuscular or intra-articular injection depending on the patient's symptoms and signs. However, in this case, due to the patient's weight and history of uncontrolled diabetes, it would be prudent to avoid steroids unless absolutely necessary.

Anti-TNF would be the next step up in management. TNF inhibitors would be a good option as they are beneficial for both skin and joints. They would have to be used cautiously due to the patient's past history of TB and unknown therapeutic regime. It is recommended to be screened for active or latent TB according to local protocols prior to commencing treatment and to treat appropriately if required.

Scant evidence that combination therapy with MTX better than monotherapy with biologics alone. However, combination therapy with MTX may help persistence of TNF inhibitors, particularly monoclonal antibodies.

Adding Sulphasalazine could be considered, but the patient has a poor prognosis (high joint count, high CRP), so it is reasonable to escalate to biologic therapy.

IL-17 inhibitors, and IL12/23 inhibitors, are a plausible option although skin not predominant problem and more real life experience with TNF inhibitors.

With the exception of option D, the other options can be considered reasonable treatment strategies in this case.

Most clinicians have experience of using anti-TNF when compared with some of the newer agents available and switching to an alternative anti-TNF is probably the most prudent option. As in this case, with secondary failure of the TNF it is likely that he will have a good response to the next TNF inhibitor.

The availability of assays for both drug and anti-drug antibodies would help to rationalise this choice.

Some clinicians may prefer to switch to a different class of drug with a different mode of action depending on the severity of disease activity.