The clinical presentation of neonatal breast infection is characterized by local signs of inflammation, such as edema, erythema, and warmth Fever is present in just 22% to 38% of cases Traditionally, the evaluation of even well-appearing infants with neonatal mastitis included blood, urine, and potentially CSF cultures; however, there is scant evidence supporting this degree of diagnostic workup There is growing evidence that demonstrates little correlation between blood, urine, or CSF cultures and causative organisms of mastitis or breast abscess Therefore, for well-appearing infants with localized mastitis, one may consider culture of purulent discharge, if present, and forgoing further evaluation for invasive infection Empiric antibiotic coverage for S aureus including CAMRSA active agents should be initiated Infants managed as outpatients require strict return precautions and close follow-up with PCP Although uncommon in neonatal mastitis, infants with signs of systemic illness have potential for invasive infections, including bacteremia, osteomyelitis, and pneumonia Therefore, a complete sepsis evaluation is indicated For hospitalized infants, initial ED therapy consists of empiric broad-spectrum intravenous antibiotic for S aureus , streptococcal organisms, and gram-negative enterics These antibiotic regimens include vancomycin plus a third-generation cephalosporins for gram-negative coverage Subsequent antibiotic therapy is guided by culture and sensitivity results If there is concern for breast abscess, incision and drainage should be done by a surgeon to minimize harm to developing breast tissue Breast infection in postpubertal females is classified as lactational or nonlactational Nonlactational mastitis/breast abscess is rare but can develop in the central or peripheral regions of the breast from introduction of skin bacteria into the ductal system Infections in the central region of breast, proximal to the nipple, are more likely in the setting of obesity, nipple piercings, or poor hygiene, while peripheral mastitis is more likely to be associated with trauma or systemic illness Other predisposing factors for mastitis include previous radiation therapy, foreign body, sebaceous cysts, hidradenitis suppurativa, and trauma to the periareolar area Signs and symptoms of infection include local erythema, warmth, pain, and tenderness and purulent nipple discharge Systemic signs, including fever, are less commonly present Organisms commonly implicated in this age group include both methicillin-sensitive and resistant S aureus, streptococcal species, Enterococcus, Pseudomonas species, and anaerobic organisms such as Bacteroides species Recommended treatment for mastitis in the postpubertal female includes initiation of anti-staphylococcal oral antibiotic therapy and warm compresses Instruct patients to keep the area clean and dry, to wear a clean cotton bra, and to