Signs of a tendon infection can include pain and tenderness along a tendon, swelling, warmth, redness, and trouble moving the nearby finger, wrist, ankle, or other body part. Pus from a nearby cut, fever, chills, or a red streak on the skin can also occur. Symptoms around a finger that becomes swollen and very painful to straighten need urgent medical assessment, even if fever is absent.
What are the common signs of a tendon infection?
A tendon is a strong band of tissue that connects a muscle to a bone. Some tendons are surrounded by a protective covering called a tendon sheath, which helps them move smoothly. When this sheath becomes infected, the condition is known as infectious tenosynovitis. The infection may cause inflammation and interfere with normal movement. According to the Cleveland Clinic, tendon sheath inflammation can result from infection, injury, or overuse, so the symptoms need to be considered in context.
Possible signs of an infection involving a tendon or its surrounding sheath include the following:
- Pain along the tendon: The affected area may hurt when touched or when the nearby finger, wrist, ankle, or other body part moves.
- Swelling: Tissue around the tendon may look puffy or enlarged. The swelling may extend along the tendon or involve a nearby joint.
- Redness and warmth: The skin over the affected area may appear red or feel warmer than the surrounding skin.
- Tenderness: Pressure over the tendon or its sheath may cause discomfort.
- Reduced movement: Pain and swelling may make it difficult to bend, straighten, grip, walk, or use the affected body part as usual.
- Changes near a wound: A cut or puncture near the affected tendon may become increasingly painful, swollen, or red. Pus may develop if the wound is infected.
The U.S. National Library of Medicine's MedlinePlus lists pain, tenderness, swelling, redness along a tendon, and difficulty moving the affected area among the possible symptoms of tenosynovitis. These symptoms can occur with noninfectious inflammation as well, so none of them confirms an infection on its own.
Which signs in the fingers or hands are especially concerning?
An infection involving the tendon sheath of a finger can be particularly urgent because swelling and infection may interfere with the tendon's ability to move smoothly. This type of infection can occur after a small cut or puncture, including an injury that initially seems minor.
According to Gloucestershire Hospitals NHS Foundation Trust, important warning signs of a flexor tendon sheath infection include:
- Swelling of a finger.
- Tenderness along the affected finger.
- Pain when the finger is straightened.
- A finger that tends to remain bent because this position is more comfortable.
These features can occur with an infection deep inside the finger, even when the skin wound is small. If a finger becomes swollen and painful to straighten, particularly after a cut, puncture, bite, or nearby infection, seek emergency medical assessment rather than waiting for the symptoms to settle.
Can a tendon infection cause fever, chills, or pus?
Yes. A tendon or tendon sheath infection may be accompanied by symptoms beyond the painful area. Fever can occur, and a nearby infected wound may produce pus. The Merck Manual Consumer Version notes that fever is common in infections of the tendon sheaths inside the fingers, along with finger swelling, pain, and tenderness.
Other concerning changes include redness that spreads beyond the original area, a red line extending along the skin away from a wound, increasing drainage, chills, or feeling generally unwell. The MedlinePlus guidance on cuts and puncture wounds identifies warmth, redness, swelling, worsening pain, fever, red streaks, and pus-like drainage as possible signs of wound infection. If these changes occur near a tendon, prompt medical evaluation is important.
A fever is not required for a tendon infection to be serious. Do not wait for fever or all the warning signs to appear before seeking help, especially when pain and swelling develop after an injury to the hand or finger.
When should you seek medical attention?
Suspected tendon infection needs prompt professional assessment because an infection in a tendon sheath may worsen and damage nearby tissues if treatment is delayed. Seek medical advice urgently on the same day if you notice new or increasing pain, swelling, redness, or warmth along a tendon, particularly after an injury, puncture wound, bite, operation, or infection of nearby skin.
Go to an emergency department promptly if you experience any of the following:
- A swollen, painful finger that is difficult to straighten or remains bent because movement hurts.
- Rapidly increasing pain or swelling around a tendon.
- Redness spreading along the affected limb or a red streak extending from a wound.
- Pus or other concerning drainage from a nearby wound.
- Fever or chills alongside pain, swelling, redness, or a suspected infection.
- Sudden difficulty moving or using the affected hand, foot, or other body part.
People with diabetes or certain conditions that affect circulation or immune function may have a greater risk of complications from infectious tenosynovitis. The threshold for seeking an assessment should therefore be low when new symptoms develop, particularly after an injury or procedure.
How is a tendon infection different from ordinary tendon inflammation?
Tendon pain does not always mean infection. Overuse, a strain, an injury, and inflammatory conditions can all cause pain, stiffness, tenderness, or swelling around a tendon. These problems may be described as tendinitis or tenosynovitis, depending on the tissues involved. Infectious tenosynovitis is different because germs are causing an infection within the tendon sheath.
Redness, warmth, fever, pus, or symptoms following a cut or puncture may raise concern for infection, but their absence does not reliably exclude it. Pain and difficulty moving can occur with both infectious and noninfectious conditions. The pattern of symptoms, how quickly they developed, whether the area was injured, and whether the symptoms are changing all help guide the assessment.
How do healthcare professionals check for a tendon infection?
A healthcare professional will ask about the timing of the symptoms, recent injuries or wounds, medical history, and any changes in movement. The affected area will be examined for tenderness, swelling, skin changes, and restricted motion. Depending on the findings, tests may be needed to assess the surrounding tissues, look for a hidden foreign object, or identify the germ responsible for an infection.
For example, the Merck Manual describes examination, X-rays to look for hidden foreign objects, and laboratory cultures of infected material as methods used when evaluating an infection of a finger's tendon sheath. The tests needed depend on the location and clinical findings. If a deep tendon sheath infection is suspected, urgent specialist assessment may be necessary, and treatment can involve antibiotics and surgical drainage.
Recognizing possible warning signs is useful, but symptoms alone cannot establish whether an infection is present. Prompt evaluation is particularly important when pain and swelling are worsening, movement becomes restricted, or symptoms follow a break in the skin.