Sir, thank you for Dr Michael Martin's lucid editorial (BDJ 2006; 200: 471) relating to the recent report published by the British Society for Antimicrobial Chemotherapy. Although patients diagnosed with the auto-immune disease Lupus Erythaematosus were not included in the three groups of at-risk patients, I have three such patients for whom I prescribe prophylactic antibiotics since I have been led to believe that they are more at risk of endocarditis following a transient bacteraemia.

I have often wondered at the need for such precautions and since none of my three patients have ever had endocarditis, would it be wise to stop this regime? One of the patients has a particularly active form of the disease and I wonder if withdrawal could be deemed negligent. I understand the arguments regarding the production of antibiotic sensitivity or allergy in such patients, but in 33 years of general practice, I have not had one such case in any patients taking prophylactic antibiotics.