Several conditions can cause pain in a child’s armpit (axilla). While most causes of pain in the armpit are not serious, there are some causes that are reason for concern. In this blog, we will cover several possible reasons for armpit pain in children.

Causes of Armpit Pain

Muscle strain

If your child plays sports or even likes to play outside, it is possible that their armpits hurt because of a muscle strain or a sprain. A muscle strain refers to a partial or complete tear of either a tendon or the muscle itself.  Sprains occur when a ligament or tendon is stretched or torn.  Muscle strains and sprains can be identified by the following:

  • History of an injury or recently using the affected arm more rigorously
  • Reduced range of motion due to pain
  • Swelling
  • Bruising
  • Tenderness when pressing over the area

Most strains are minor and can be treated at home with ice and pain relievers while resting the affected arm. Most cases do not need medical attention, but you should talk to your doctor if symptoms persist for more than a few days or worsen.

Skin irritation or allergic reaction

Although skin irritation or allergic reactions usually cause itching more than pain, your child’s armpit pain may also be caused by an irritant if it becomes serious enough. Common skin irritants include the following:

  • Soaps and body washes
  • Laundry detergent
  • Deodorants
  • Powders

In the case of eczema, the irritant often remains unknown.

Treating this kind of pain usually involves avoiding the irritants and applying hydrocortisone cream (available over the counter such as Cortaid) until the irritation resolves. This may mean experimenting with different soaps and detergents to determine the root cause of the irritation. Irritation that doesn’t resolve or becomes inflamed should be evaluated by your doctor.

Bacterial infection

A bacterial infection of the armpit could cause your child’s armpit pain. This may be a superficial infection of the skin such as folliculitis (an infection of the hair follicles), or deeper such as hidradenitis suppurativa (an infection of the sweat glands) or a subcutaneous abscess (collection of pus under the skin layer).  These are more common in the following situations:

  • Living in hot or humid climates
  • Excessive sweating
  • Shaving
  • Obesity
  • Athletes
  • Healthcare workers

This infection can be diagnosed by a doctor and is usually treated with antibiotics, either topical or oral.


Of the possible causes of armpit pain, lymphadenopathy is potentially one of the more serious. Lymphadenopathy refers to the swelling lymph nodes (glands) which are part of the body’s immune system and function to filter the fluid in the tissues (lymph fluid).  If tissue becomes infected, the lymph nodes in that area often swell or can themselves get infected.  When they do, they feel like jelly beans beneath the skin and can be red and tender.  For example, a case of strep throat often causes the lymph nodes in the neck to swell.  After the infection resolves, lymph nodes usually return to their usual size and shape.  

Swollen lymph nodes in the armpit are usually associated with an infection of the arm or hand.  Sometimes, they occur with a more systemic infection like mononucleosis (“mono”).  Rarely, they occur in the setting of cancer.  As with most lymphadenopathy, after the infection resolves, the nodes usually return to their initial size and shape.  But if they continue to enlarge or don’t resolve, or are associated with other symptoms like fever or weight loss, your doctor should evaluate them right away.  

When to Seek Medical Attention for Armpit Pain

As mentioned above, most of the time your child’s armpit pain will go away on its own, but the following symptoms warrant medical treatment:

  • Severe pain
  • Persistent pain
  • Persistent swelling
  • Fever or worrisome symptoms elsewhere


If your child is experiencing pain in their armpits, ask them about any recent injury or increased use of the arm that would suggest an injury, and inspect the area for any of the concerns listed above. If you find anything of concern, see your doctor.