Abstract
Mastitis and breast abscesses are most common in lactating women but can also be observed in non-lactating women, adolescent girls, and neonates. However, breast abscesses are extremely rare in young boys. Herein, we report the case of a three-year-old boy with a swollen and painful right nipple, later diagnosed with a breast abscess. In this case, we suspected that the patient's inverted nipple was the possible site of the infection. To our best knowledge, this is the first case report of breast abscess in a young boy after the neonatal period. Although Staphylococcus aureus is the most common pathogen, our patient showed three rare bacteria, namely, Peptoniphilus harei, Actinotignum sanguinis, and Porphyromonas somerae, in the culture of the aspirated pus. Furthermore, this case study is the first report of a breast abscess caused by Porphyromonas somerae.