指头炎（指尖软组织感染）

This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.

Anatomy & Pathophysiology¶

Anatomical Structure of the Digital Pulp¶

• A felon is defined as an abscess located in the subcutaneous tissues of the distal pulp of a finger or thumb [2].
• The distal digital pulp is divided into tiny compartments by strong fibrous septa that traverse from skin to bone [2].
• A transverse fibrous curtain is present at the distal flexor finger crease [2].
• The tight septal compartment of the pulp causes immediate pain when swelling occurs due to increased pressure within the space [2].
• The pulp space infection is characterized as a deep infection within a tight septal compartment [14].

Pathophysiology and Complications¶

• Infection in the pulp is commonly caused by penetrating injuries from foreign bodies or medical finger sticks [2].
• Staphylococcus aureus is the organism most commonly isolated from fingertip infections [2, 14].
• Initial clinical signs of pulp infection include swelling, redness, and pain typical of cellulitis [2].
• Abscess formation may follow rapidly after the initial signs of cellulitis [2].
• A pulp abscess can extend into the periosteum around the nail bed, causing paronychia [2].
• A pulp abscess can extend proximally through the fibrous curtain into the flexor sheath, leading to flexor tenosynovitis [2].
• Deep abscesses that are untreated can penetrate the periosteum and cause osteomyelitis or septic joint [2].
• More superficial abscesses can cause skin necrosis [2].
• Abscesses may occasionally form in the middle and proximal digital pulps [2].
• If a felon lesion is relatively superficial, the purulence may point palmarly, a condition known as an apical abscess [14].
• Complications of a felon include loss of pulp tissue, osteomyelitis, epiphyseal damage, and septic arthritis [14].

Clinical Presentation¶

• A felon is an abscess in the subcutaneous tissues of the distal pulp of a finger or thumb [2].
• The distal digital pulp is divided into tiny compartments by strong fibrous septa that traverse it from skin to bone [2].
• Swelling causes immediate pain due to increased pressure within the pulp [2].
• Infection can be caused by a penetrating injury from a foreign body [2].
• Infection can be caused by "finger sticks" for medical reasons, such as hematocrit and blood glucose determinations [2].
• S. aureus is the organism most commonly isolated from fingertip infections [2].
• Swelling, redness, and pain typical of cellulitis are present initially [2].
• Abscess formation may follow rapidly after initial cellulitis symptoms [2].
• The pulp abscess can extend into the periosteum around the nail bed causing paronychia [2].
• The pulp abscess can extend proximally through the fibrous curtain into the flexor sheath, leading to flexor tenosynovitis [2].
• Abscesses beginning deep, especially if untreated, penetrate the periosteum and cause osteomyelitis or septic joint [2].
• More superficial abscesses cause skin necrosis [2].
• Abscesses may form occasionally in the middle and proximal digital pulps [2].
• The diagnosis of an abscess in this area is sometimes difficult [2].
• An abscess is usually present if severe pain has lasted for 12 hours or longer [2].

Clinical Examination¶

• A careful physical examination is essential to direct care and future testing if indicated [1].
• Diagnostic tests such as imaging and serum laboratory studies can be expensive, time consuming, and often nonspecific [1].
• Patients often have difficulty accurately describing their symptoms and may incorrectly attribute pathology to a perceived deficit [1].
• The task of the clinician is to combine patient history with a careful physical examination to pinpoint or narrow the scope of possible pathologic processes [1].

Imaging¶

• An 8-MHz Doppler tone assessment may be used to identify superficially displaced neurovascular bundles when Dupuytren cords lie beneath soft fleshy prominences [12].
• False-negatives are possible with 8-MHz Doppler tone assessment [12].
• Doppler imaging is a promising improvement for identifying structures, but higher resolution imaging technology is needed [12].
• MR assessment of Dupuytren’s is hindered by the resolution of current equipment, orientation issues due to multiplanar deformities of the fingers, and lack of intraoperative availability [12].
• MRI is probably most useful in identifying additional pathology such as flexor tendon bowstringing [12].
• MRI may be helpful in providing a quantitative noninvasive measure of cellularity of affected areas, which is an index of biologic activity [12].
• The potential of MRI as a staging tool based on cellularity has not been investigated yet on a large scale [12].

References¶

[1] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Anatomy, Evaluation, Clinical Examination, and Imaging > Evaluation and Clinical Examination: Current Concepts.

[2] Campbell S Operative Orthopaedics 4 Volume Set. TUMORS AND TUMOROUS CONDITIONS OF THE HAND > FELON.

[12] Dupuytren S Disease And Related Hyperproliferative Disorders. 54. The Future of Dupuytren’s Research and Treatment > 54.4 Mechanical Measurements and Procedures > 54.4.4 Imaging.

[14] Tachdjian S Pediatric Orthopaedics From The Texas Scottish Rite Hospital For Children E Book. Felon.