The breast tissue infection of mastitis and association with abscess is very rare in the neonatal period. Generally, it is observed in term infants. The rarer observation in preterm infants is thought to be linked to less development of breast tissue (2, 4, 7).
It is observed in the first 1–6 weeks of life, with incidence increasing in the 2nd -3rd weeks (5, 8–11). Mostly unilateral, there are cases with bilateral mastitis developing in the literature, as in our case (12, 13). Generally, it is observed 2 times more in girls; however, no sex difference was determined for the first two weeks of life. This situation is thought to be linked to the physiological breast growth in girls being observed more after the second week.
The pathogenesis of mastitis is not fully known. However, infection is thought to develop mostly from skin flora entering the nipple with retrograde spread via the ductal canals (2, 7). In the literature, there are cases reporting mastitis and breast abscess in the infants of breastfeeding mothers with postpartum breast abscess. In these cases, the mastitis vector is the mother was identified to be the same as in the infant. It is thought that microorganisms in breastmilk cause bacteremia in the infant leading to mastitis and breast abscess. Among vectors identified in reported cases are methicillin-resistant Staphylococcus aureus and group B streptococci (14, 15). When our patient is assessed in terms of the mother, there were no symptoms or findings leading to consideration of mastitis or abscess in the mother. Abscess formation is reported in 40–70% of infants with mastitis and generally is observed in cases with insufficient treatment (2, 4, 7).
Initially breasts are identified to have growth, erythema, induration, tension and temperature increase. The skin around the affected breast tissue changes and axillary lymph node growth may be observed. If abscess formation develops, fluctuation may be taken (7). In our case, 2 days before admission, erythema and swelling had begun in the breasts and bilateral breast abscess was identified. Elevated fever, restlessness and toxic appearance is present in 30% of patients. Leukocytosis and CRP elevation is observed in 50–70% of cases (2, 8). In 83–88% of cases, the vector is Staphylococcus aureus (2, 4, 8, 12). Other vectors are gram negative organisms like Escherichia coli, Klebsiella, Shigella, Salmonella and Pseudomonas (4, 7, 11, 14, 16). Infections formed by anaerobic peptostreptococci, Staphylococcus epidermis, Group D and B streptococci are reported (12, 14). Anaerobic vectors are identified in 40% of cases; however, the place in the etiology is controversial and it is not recommended to start direct antibiotherapy for these vectors (8, 9). Abscess linked to Staphylococcus aureus may be observed especially in the periumbilical and perineal regions on the trunk as pustular and bullous lesions (4). Symptoms, onset age and clinical findings are similar to infections linked to gram negative basilar and anaerobic vectors and staphylococcic infections. Cases infected with salmonella strains may have gastrointestinal findings observed (11). Infants with subclinical mastitis may be restless and cry excessively and be diagnosed with infantile colic (17). In our cases, the initial symptoms noticed by the family were redness and swelling of the two breasts. The patient was assessed in terms of galactorrhea due to discharge from the left breast. FSH, LH, E2 and prolactin levels were within normal limits.
Clinical assessment is the first stage of diagnosis. Ultrasonography is important for assessment of cases developing abscess especially. Abscess diagnosis may be made in the presence of fluctuation; however, fluctuation may not be observed in the presence of induration. The finding for mastitis on ultrasonography is increased echogenicity. Abscess provides findings of hyperechoic or hypoechoic avascular mass (18).
Gram staining and culture results direct treatment. If fluctuation is present, the abscess should definitely be drained. In situations without abscess, antibiotherapy alone is curative. Warm compresses may be beneficial. Initially, β lactamase-resistant anti-staphylococcal antibiotics should be chosen; however, in locations with high incidence of MRSA infection, vancomycin or clindamycin may be started. If gram negative basilar is observed on gram staining or if no microorganism is observed, and the infant has septic appearance, initial treatment should have aminoglycoside or cefotaxime added. In our case, due to the bilateral abscess and high infection symptoms, empirical vancomycin and cefotaxime treatment was begun intravenously. Cefotaxime treatment was stopped according to culture and antibiogram results and vancomycin continued. In most cases, 5–7 days of treatment is sufficient; however, treatment may be extended to 10–14 days according to the isolated vector, patient’s clinical status and presence of bacteremia.
The most common complication of neonatal mastitis is cellulitis observed at rates of 5–10%. Generally, it is localized; however, it may rarely spread to the shoulder and abdomen (2, 10). Other rare complications are fasciitis, osteomyelitis, meningitis, cerebral abscess and sepsis (2, 4–6). There is no definite data related to late period complications, but even in cases treated appropriately some cosmetic problems like scar development, hypoplasia and asymmetry may occur. It may cause problems with breast development in adolescent girls.
As a result, families should be informed about physiological breast hypertrophy and galactorrhea and mistaken interventions should be prevented.