Persistent infection of the chin with an unusual skin pathogen (Streptococcus milleri ): a sign of intraoral carcinoma

Streptococcus milleri is a commensal of the oropharynx and gastrointestinal tract which is not generally associated with skin disease. We now report a patient who presented with a pustular mass of the chin with lower lip anaesthesia. He was initially thought to have sycosis barbae, but response to treatment was poor and lesional swabs repeatedly cultured S. milleri. After some delay, squamous cell carcinoma of the mouth, involving the mandible and overlying skin, was detected. We consider that the S. milleri either invaded through the tumour from the mouth or root canal or colonized the skin from saliva dribbled over the numb lower lip. Isolation of an unusual organism and numbness of the chin are features that should suggest the need for early radiography.