Failure of oral penicillin as secondary prophylaxis for rheumatic heart disease: a lesson from a low-prevalence rheumatic fever region.

Our patient is an 18-year-old Caucasian woman from the UK who developed severe mitral stenosis on a history of childhood acute rheumatic fever (ARF) and rheumatic heart disease (RHD). She had been reporting of her oral penicillin secondary prophylaxis regimen since diagnosis. At the age of 15 years, a new murmur was discovered during routine cardiac follow-up. An echocardiogram confirmed moderate-severe mitral stenosis. One year later, her exercise tolerance significantly deteriorated and she subsequently underwent balloon valvuloplasty of her mitral valve to good effect. Our case emphasises the evidence base supporting the use of monthly intramuscular penicillin injection to prevent ARF recurrence and RHD progression; it also emphasises the reduced efficacy of oral penicillin prophylaxis in this context. It particularly resonates with regions of low rheumatic fever endemicity. The long-term cardiac sequelae of ARF can be devastating; prescribing the most effective secondary prophylaxis regimen is essential.