Counsel a family on CVID arthritis and the need for a dual plan — OSCE

Candidate brief

You have eight minutes to counsel the parents of a six-year-old girl in whom a rheumatic-immune overlap — common variable immunodeficiency with arthritis, chronic diarrhoea, and autoimmune thrombocytopenia — is suspected alongside a plan to start a biologic for presumed juvenile idiopathic arthritis. Use a structured, honest, empathic approach. [3] [8]

Key teaching and communication objectives

Acknowledge and validate the parents' fear and confusion before delivering information. Explain, in plain language, that their daughter's joints and her immune system are linked because the same part of the immune system that fights infection also normally stops the body from attacking itself — and in her case both jobs are failing. Reassure them that this is genetic but not anyone's fault. [3] [1]

Explain why the biologic must wait. A medicine that switches down the immune system is exactly the wrong first step before the immune defect is confirmed, because it can suppress a system that is already struggling and invite serious infection. Frame the pause as a safeguard, not a delay: the right plan depends on confirming the cause rather than acting on a single label. [7]

Set honest expectations about treatment. Immunoglobulin replacement — regular antibody infusions or injections — will protect her against infection, but it will not by itself fix the arthritis or the bruising, because those come from a different part of the immune failure. The plan is therefore to treat both arms in parallel: the immunoglobulin for the infection susceptibility, and a carefully chosen, steroid-sparing medicine for the joints and platelets, led jointly by the immunology and rheumatology teams. [7] [3]

Close with a shared plan and a clear next step: confirm the diagnosis with the vaccine response and further immune tests, defer the biologic until those return, involve both specialist teams, and offer written information and a patient-support organisation. Leave the family with a single sentence they can repeat: "her joints and her immune system are linked, we are confirming the cause before any new medicine, and we will treat both together." [3] [8]