Sterile Abscess After a Shot: How to Care for Your Child

An abscess is a buildup of fluid under the skin that feels like a soft lump. It usually happens when a skin infection develops and cells gather to fight bacteria, forming a collection of pus. A different type of abscess, called a "sterile abscess," may develop after an injection (shot). It's called "sterile" because there is no infection or bacteria; it is full of fluid only. Sometimes the health care provider drains the fluid from the abscess.

• Follow the health care provider's directions for keeping the area around the abscess clean.

• You can give medicine for pain if your health care provider says it's OK. Use these medicines exactly as directed:

  • acetaminophen (such as Tylenol® or a store brand)

  • OR

  • ibuprofen (such as Advil®, Motrin®, or a store brand). Do not give to babies under 6 months old.

• If the abscess starts draining on its own or if the health care provider drained it, soak the area in warm water for 10 minutes (3–4 times a day) to help it finish draining. 

  • Lower the body part with the abscess into a tub of warm, soapy water. OR

  • Place a clean, warm, wet washcloth on the abscess. 

  • Stop the soaks when there is no more drainage.

• Cover the open or draining abscess with clean gauze or a bandage. Change the gauze or bandage if it gets dirty or wet.

Your child:

• has pain, redness, or swelling around the abscess

• has fluid draining from the abscess for longer than a few days

• has fluid that builds up again after the abscess was drained

• has a fever or chills

• develops red streaks around the abscess

Why do some people get a sterile abscess after a shot? A sterile abscess can form when an injected medicine doesn't get fully absorbed into the body. Or it can happen if a child is sensitive to part of the medicine, causing a reaction that leads to fluid buildup.

Does a sterile abscess always have to drain? A sterile abscess might go away on its own. This can happen when a soft lump shrinks as the fluid slowly goes away, or when the fluid drains out by itself.