Adding Salt to the Wound
Case
A 28-year-old male with no past medical history presents to the emergency department with two days of gradually worsening right index finger pain and swelling. The patient reports that he works on a saltwater fishing boat and frequently has cuts on his hand. A few days ago, he noticed worsening pain and swelling to a cut on his right index finger. Today, the pain worsened and he is having difficulty bending his finger. He states that the pain radiates from his index finger up his hand and right forearm. He has not had any fevers and there is no associated numbness or tingling.
On exam, he has significant swelling of his right index finger with some associated swelling to the right middle finger and palmar surface of the hand. His right index finger is slightly flexed and his pain is worse if you palpate the flexor surface, or attempt to extend the finger. Sensation of the digit is intact and he has good capillary refill. There is a small healing laceration on the palmar and lateral aspect of the index finger but no drainage from the area.
An x-ray is done to rule out foreign body.
Based on the patient’s symptoms and physical exam findings, he is diagnosed with Flexor tenosynovitis (FTS). The patient undergoes bedside I &D by surgery and is started on IV Levofloxacin, Cefazolin and Doxycycline.
What is flexor tenosynovitis (FTS)?
Flexor tenosynovitis is inflammation of a flexor tendon and the surrounding sheath. If the inflammation progresses it can spread to adjacent compartments and may cause enough swelling to cause compartment syndrome. There are several different causes for this inflammation. The most common etiology is penetrating trauma in the form of a laceration, puncture wound, or bite wound. This was the likely etiology for this patient given the healing laceration found on exam. Depending on the nature of the trauma, different bacteria may be responsible for causing infection. Skin flora such as staph or strep are the most common pathogens. In this patient’s case, he is a salt water fisherman and thus the need to consider Mycobacterium marinum, Mycobacterium fortuitum or Vibrio vulnificus as potential pathogens.
How is FTS diagnosed?
FTS is a clinical diagnosis. Patients may present with systemic symptoms of illness such as fever, tachycardia, hypotension or elevated WBC count. However, if the infection is more localized, these signs and symptoms may be absent. The Kanavel Signs are a set of criteria that are helpful in diagnosing FTS. The four signs are:
Pain along flexor surface with passive extension (early sign)
Fusiform swelling of the finger (sausage digit)
Finger held in passive flexion
Tenderness along flexor surface (late sign)
It is important to note that while The Kanavel signs are very sensitive for FTS, they are not highly specific.
How is FTS treated?
This patient presented fairly early after the swelling and pain started and was successfully treated with bedside I&D along with IV antibiotics. In more advanced cases, patient may require surgery for a more thorough debridement and washout. This usually requires an urgent hand consult due to the potential for rapidly progressing infection. In a small subset of patients with very early infection, they may be successfully treated with antibiotic therapy without need for I & D or surgery. These patients usually present with milder symptoms including only localized inflammation (not fusiform swelling), ability to flex finger, and minimal pain with passive motion of involved tendon.
In patients without significant comorbidities, such as diabetes, or risk factors for potential marine exposure, Vancomycin and Ceftriaxone are the recommended first line antibiotic therapy. Pseudomonal coverage must also be considered in diabetic patients. If there is a history of salt water exposure, as in this patient, it is important to cover the patient broadly with a cephalosporin and fluoroquinolone. Bactrim can also be added for additional marine coverage which covers organisms such as Chromobacterium violaceum and Mycobacterium marium, while addition of Doxycycline covers organisms such as Mycobacterium fortuitum and Vibrio vulnificus. In this patient’s case, with his marine exposure, he was started on Cefazolin, Levofloxacin, and Doxycycline. He was admitted for two nights on IV antibiotics with significant improvement in pain and swelling. On hospital day three, he was transitioned to PO medications and discharged home.
Faculty Reviewer: Dr. Kristina McAteer
Sources:
Diaz, James H., and Fred A. Lopez. “Skin Soft Tissue and Systemic Bacterial Infections Following Aquatic Injuries and Exposures.” The American Journal of the Medical Sciences, vol. 349, no. 3, 2015, pp. 269–275.
Kennedy, Colin D., et al. “Differentiation Between Pyogenic Flexor Tenosynovitis and Other Finger Infections.” Hand, vol. 12, no. 6, 2017, pp. 585–590.
Small, Lorne N., and John J. Ross. “Suppurative Tenosynovitis and Septic Bursitis.” Infectious Disease Clinics of North America, vol. 19, no. 4, 2005, pp. 991–1005.