Mastitis is inflammation (soreness and swelling) of the breast caused by an infection. The breast is usually painful, red, warm, and swollen. The lymph nodes under the arm may swell, and there may be discharge from the nipple.

Babies under 2 months old who have mastitis are treated with IV (given into a vein) antibiotics. Sometimes, the health care provider needs to remove the infected fluid from the breast area with a needle.

Your baby was treated in the hospital and is doing well. You can now give the antibiotic by mouth and care for your baby at home.

• Give your baby all the antibiotics as directed by the health care provider even if your baby seems better. This is the best way to treat the infection.
• If your baby seems uncomfortable and your health care provider says it's OK, you can give acetaminophen (such as Tylenol^® or a store brand). Follow the directions on the label for how much to give and how often.
• To care for the infected area:
  • Wash the area daily with a gentle soap and dry with a clean towel.
  • Place a warm compress (a warm, damp washcloth) on the area for about 15 minutes a few times a day.
  • Don't push on or squeeze the area.
• Go to all follow-up visits as directed.

Your baby:

• doesn't continue to get better as you follow the health care provider's instructions
• has new or increased:
  • redness, swelling, or pain of the breast
  • discharge from the nipple
• gets a new rash or redness anywhere on the skin
• can't take the medicine
• isn't feeding well

Your baby:

• has a new or higher fever
• has red streaks spreading from the infected area
• seems to be getting worse or seems very ill

What causes mastitis? It happens when bacteria (a type of germ) that normally lives on the skin or in the nose/mouth gets into the breast (usually through the nipple) and causes an infection. Mastitis usually affects only one breast.

Can mastitis cause long-term problems? Most babies with mastitis recover completely with no lasting problems.