Long-term, low-dose of clarithromycin as a cause of community-acquired Clostridium difficile infection in a 5-year-old boy.

Clostridium difficile is one of the most common causes of antibiotic-associated diarrhoea. Despite C. difficile infection (CDI) has increased in all ages worldwide, episodes of CDI are often misdiagnosed due to the lack of clinical suspicion. Macrolides are also associated with CDI. Additionally, exposure to macrolides in the 12 weeks preceding infection is reported to be a significant risk factor of CDI in a child. We report here a 5-year-old Japanese boy who presented with acute onset of watery diarrhoea. He was diagnosed with community-acquired CDI induced by long-term (20 weeks), low-dose, oral clarithromycin for otitis media with effusion, and he recovered by conservative treatment. Physicians should be more cautious of community-acquired CDI in children who take long-term, low-dose macrolides, not to misdiagnose as diarrhoea by its side effect, and avoid unnecessary use of systemic antibiotics.