Panaritium

Anatomical traps of the hand

The skin of the palmar surface is dense, fused with the palmar aponeurosis, and lacks sebaceous glands. The subcutaneous adipose tissue has a honeycomb structure: numerous vertical strands tightly connect the dermis to the aponeurosis. These connective tissue fibers play a dual role in pathogenesis.

On the one hand, they block the lateral spread of inflammation. On the other hand, they serve as a direct conduit for the infection inward, toward the tendons and bones. It is the tension of these structures during exudate accumulation that causes excruciating, bursting pain.

Important clinical nuance: the dorsal surface of the hand features loose tissue and active lymphatic drainage. Because of this, an abscess located on the palm is almost always accompanied by pronounced edema and redness of the hand's dorsum, while the signs on the palm itself may be masked (only smoothing of contours). The surgeon must always rely on localized pain upon palpation with a button probe; otherwise, incisions will be incorrectly placed, critically impairing hand function. Also, during surgery, it is important to remember the "forbidden zone"—the projection of the motor branch of the n. medianus, damage to which threatens paralysis of the thenar muscles.

Superficial forms of felon

Superficial lesions are the most common and affect the skin, nails, and subcutaneous tissue.

• Cutaneous felon. The infection is localized beneath the epidermis. A blister forms containing serous, purulent, or hemorrhagic fluid.
• Subcutaneous felon. The most frequent variant. During the first 24 hours, working capacity is preserved, followed by increasing throbbing pain. Hyperemia is mild, but the tissues are tense. The focus is precisely defined by localized tenderness.
• Paronychia. Inflammation of the perionychium, which swells and overhangs the nail plate. If pus breaks through beneath the nail, the process progresses to the next form.
• Subungual felon. The exudate separates the nail plate from its bed. The patient experiences throbbing pain. Treatment ranges from simple trepanation (drilling a hole in the nail) to complete nail plate removal.

Deep forms and complications

If the infection breaks through the protective barriers, severe deep forms develop, requiring complex surgical intervention.

• Tendon felon (tenosynovitis). The finger swells uniformly ("sausage-shaped") and assumes a forced semi-flexed position. Attempting passive extension provokes excruciating pain. The accumulation of pus compresses the vessels of the tendinous mesentery, causing rapid ischemia and tendon necrosis—emergency surgery is required.
• Articular felon. Develops from joint injuries on the dorsal side. The joint becomes fusiform, and ligaments and cartilage are destroyed.
• Bone felon. A secondary complication of soft tissue forms. The pain changes from throbbing to dull and constant, and the phalanx becomes club-shaped. On X-rays, bone destruction (sequestra) is visible only by the end of the second or third week.
• Pandactylitis. Total involvement of all finger structures. The finger is bluish-purple, tissues are necrotic, and severe intoxication and lymph node inflammation are present.

Principles of treatment

Conservative therapy (alcohol compresses, antibiotics, enzyme electrophoresis, UHF therapy) is justified only in the serous-infiltrative phase. As soon as the inflammation becomes purulent, surgery is indicated.

Digital incisions are made strictly along the lateral surfaces (linearly). This is necessary to preserve the innervation of the working palmar surface and prevent scar formation at the flexion creases. In severe phlegmons, such as U-shaped phlegmon (involving the synovial sheaths of the 1st and 5th digits), pus may rupture into the deep Pirogov-Parona space in the forearm. In such cases, through-and-through irrigation drainage is performed with additional incisions in the lower third of the forearm.

Class and exam questions

What else to study on this topic

• Boundaries and clinical significance of the "forbidden zone" of the hand (projection of the motor branch of the median nerve)
• Topography of hand fasciae: the midpalmar space and thenar/hypothenar regions
• Classification and technique of surgical interventions on the nail plate
• Pathways of pus spread in U-shaped phlegmon and the anatomy of the Pirogov-Parona space

Other topics from the section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.