RT Book, Section
A1 Shah, Ashish
A1 Sobolewski, Brad
A1 Mittiga, Matthew R.
A2 Knoop, Kevin J.
A2 Stack, Lawrence B.
A2 Storrow, Alan B.
A2 Thurman, R. Jason
SR Print(0)
ID 1181044277
T1 Neonatal Mastitis
T2 The Atlas of Emergency Medicine, 5e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260134940
LK accessmedicine.mhmedical.com/content.aspx?aid=1181044277
RD 2024/04/19
AB Neonatal  mastitis  is  an  infection  of  the  breast  tissue  that  occurs  in  full-term  neonates.  The  peak  incidence  of  mastitis  without  abscess  is  in  the  2nd  week  of  life  and  the  4th  week  of  life  for  mastitis  with  abscess.  Females  are  affected  more  often  than  males  in  a  2:1  distribution.  Clinically,  it  manifests  as  swelling,  induration,  erythema,  warmth,  and  tenderness  of  the  affected  breast.  The  ipsilateral  axillary  lymph  nodes  may  be  swollen.  Approximately  50%  develop  an  abscess.  In  some  cases,  purulent  discharge  may  be  expressed  from  the  nipple.  Fever  may  be  present  in  25%  of  affected  patients.  Other  systemic  symptoms  (irritability,  decreased  appetite,  and  vomiting)  are  less  common  but  indicate  a  more  severe  infection  if  present.  Bacteremia  is  rare.  Staphylococcus  aureus,  specifically  methicillin-resistant  strains  (MRSA),  is  the  most  common  pathogen,  causing  75%  to  85%  of  cases.  Rarely,  gram-negative  organisms  or  group  B  or  D  streptococci  are  the  cause.  If  treatment  is  delayed,  mastitis  may  progress  rapidly  with  involvement  of  subcutaneous  tissues  and  subsequent  toxicity.  In  the  initial  stages,  neonatal  mastitis  may  mimic  mammary  tissue  hypertrophy  owing  to  maternal  passive  hormonal  stimulation.  Minor  trauma,  cutaneous  infections,  and  duct  blockage  may  precede  this  infection.