Too much of a good thing: management of BCG vaccine overdose.

A 14-year-old girl was inadvertently immunised with an excessively large dose of BCG-Connaught vaccine (1.0 ml instead of 0.1 ml). Examination of the patient a few hours later revealed a subcutaneous fluctuant tender lump at the injection site. This was surgically excised within 12h of immunisation and she was treated with isoniazid and rifampicin for six weeks. The patient developed no complications, other than a minor surgical scar. This case highlights the importance of the correct administration and dosing of BCG vaccine and suggests a management option that may prevent the severe local and systemic complications that are frequently associated with BCG overdose.