Springdale Mason Pediatrics

Lymph Node Infection - Bacterial


  • A bacterial infection of a lymph node
  • Main symptom is the sudden onset of one large painful node

Call or Return If

  • Fever lasts more than 2 days after starting antibiotics
  • Symptoms become worse on treatment
  • Lymph node comes to a head and needs to be drained
  • You think your child needs to be seen
  • Your child becomes worse

About This Topic


  • Sudden increased size of a lymph node in the neck. Always a single node. Sometimes, it happens to a node in the armpit or groin.
  • It's much larger than the same node on the other side of the body. Sometimes, the skin that covers the node becomes red.
  • Swollen nodes with a bacterial infection are usually over 1 inch (25 mm) across. This is about the size of a quarter.
  • Normal nodes are usually less than ½ inch (12 mm) across. This is the size of a pea or baked bean. They also feel soft and are easy to move.


  • Seen with bacterial infections of the nose, sinuses, mouth or throat. A strep throat infection is a common cause.
  • One swollen, tender node under the jawbone can be caused by bad tooth decay.

Common Objects Used to Guess the Size

  • Pea or pencil eraser- 1/4 inch or 6 mm
  • Dime- 3/4 inch or 18 mm
  • Quarter- 1 inch or 2.4 cm
  • Golf ball- 1 1/2 inches or 3.6 cm
  • Tennis Ball- 2 1/2 inches or 6 cm

After Care Advice

  • Bacterial lymph node infections always need a prescription for an antibiotic.
  • Most children get better slowly over 2 to 3 days. They do not respond to the first dose.
  • Here is some care advice that should help.
Antibiotic by Mouth:
  • The antibiotic will kill the bacteria that are causing the lymph node infection.
  • Give the antibiotic as directed.
  • Try not to forget any of the doses.
  • Give the antibiotic until it is gone. Reason: To stop the lymph node infection from flaring up again.
Pain Medicine:
  • To help with the pain, give acetaminophen (such as Tylenol) or ibuprofen. Use as needed.
  • For fevers above 102° F (39° C), give acetaminophen (such as Tylenol) or ibuprofen. Note: Lower fevers are important for fighting infections.
  • For ALL fevers: Keep your child well hydrated. Give lots of cold fluids.
Avoid Squeezing:
  • Don't squeeze lymph nodes.
  • Reason: It could force bacteria into the bloodstream. It also can slow down the return to normal size.
What to Expect:
  • Once on antibiotics, your child will get better in 2 or 3 days.
  • After the infection is gone, the node will slowly return to normal size.
  • This may take 4 to 6 weeks.
  • However, it won't ever completely go away.
  • If the infected node became soft in the middle, it needs to be drained. Reason: To release the pocket of pus. Don't try to do this on your own. Call your child's doctor.
Return to School:
  • Your child can return to school after the fever is gone.
  • Your child should feel well enough to join in normal activities.
  • Lymph node infections cannot be spread to others.

Author: Barton Schmitt MD, FAAP
Copyright 2000-2021 Schmitt Pediatric Guidelines LLC
Disclaimer: This health information is for educational purposes only. You the reader assume full responsibility for how you choose to use it.
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