Empyema of the finger tip

　　Empyema of the finger tip is a subcutaneous suppurative infection of the palm of the distal phalanx of the finger, mostly caused by an injury. There are many longitudinal fibrous strands between the skin of the distal palmar phalanx and the nail phalanx membrane, which classify the soft tissue into many closed small compartments containing fat tissue and a rich network of nerve endings. When infection occurs, pus is not easy to spread to the surrounding area, so the swelling is not significant. However, the high-pressure pus cavity can not only cause very severe pain but also compress the nutrient vessels of the distal phalanx bone, causing ischemia and necrosis of the phalanx bone. In addition, direct invasion of the pus into the phalanx bone can also cause osteomyelitis.

　　Empyema of the finger tip is caused by an injury, and the pathogenic bacteria are mostly Staphylococcus aureus. The disease is treatable in a timely manner, with pus discharged and the wound healed, leading to a good prognosis; however, if misdiagnosed or mismanaged, most of the finger tip tissue may suffer ischemic necrosis in the late stage, the nerve endings may become paralyzed due to compression and nutritional disorders, the pain may反而减轻, and complications such as ischemic necrosis of the phalanx bone may occur, leading to osteomyelitis of the phalanx bone.

　　Local pain is the main symptom of purulent phalangeal inflammation. At the beginning, it is mostly piercing pain, and as the local inflammation worsens, the pressure in the inter-space of the finger pulp increases, resulting in local severe pain. When the finger arteries on both sides are compressed, there may be a pulsating jumping pain. When the hand is hanging down or the tip of the finger is lightly tapped, due to increased pressure, the pain becomes more severe, and the patient often finds it hard to bear. At night, due to severe pain, the patient often cannot sleep. The tip of the finger may have redness and swelling, but it is not obvious. As the pressure in the subcutaneous cavity of the finger pulp increases, there is a disturbance in blood circulation, and the tip of the finger may present yellowish color. If not treated in time, it can form chronic osteomyelitis. Purulent phalangeal inflammation often has varying degrees of systemic infection and toxic symptoms, such as fever, fatigue, decreased appetite, and so on, and the blood routine examination may show an increase in white blood cell count.

　　When pain is felt at the tip of the finger, and the examination finds that the swelling is not obvious, it can be soaked in hot salt water multiple times, about 20 minutes each time, or the medicine can be applied externally (refer to the treatment of paronychia). According to the situation, sulfonamide drugs or antibiotics can be used. After the above treatment, inflammation can often be subsided. If jumping pain appears and the tension of the finger tip increases significantly, it should be incised for decompression and drainage immediately. Even if there is little pus or no pus after the incision, it can reduce the pressure in the sealed cavity of the finger tip, reduce pain and complications.

　　Purulent phalangeal inflammation is mainly caused by piercing injuries and is relatively common in daily life. Below, the editor will introduce the laboratory tests that need to be done for purulent phalangeal inflammation.

　　1. Blood routine examination:The total white blood cell count and neutrophils increase.

　　2. X-ray examination:It can be found that there is osteomyelitis or dead bone in the phalanx.

　　3. Transillumination examination for pus:A deep black shadow at the tip of the finger indicates that pus has formed.

　　Purulent phalangeal inflammation is mainly caused by piercing injuries. Below, the editor will introduce the dietary taboos for purulent phalangeal inflammation.

　　Purulent phalangeal inflammation is best to eat light and easy-to-digest foods, and avoid spicy and greasy foods.

　　The distal phalanx of the finger has many radial fibrous bands centered around the phalanx, which form many small compartments. When purulent phalangeal inflammation occurs, the inflammatory edema in the small compartments continues to increase in pressure, not only compressing the distal nerve endings to cause severe pain, but also, more seriously, the distal phalanx will become ischemic and necrotic before the abscess forms, leading to an incurable osteomyelitis of the phalanx. Therefore, early incision and drainage should be performed.

　　Indications:

　　When the finger tip inflammation presents with jumping pain and obvious swelling, it should be incised immediately for decompression and drainage, and it cannot wait for the fluctuation to appear.

　　Preoperative preparation:

　　1. Choose antibiotics rationally according to the condition.

　　For patients with severe hand infection and weakened overall condition, attention should be paid to improving the overall condition and enhancing the body's resistance.

　　When incising a deep abscess in the hand, it is advisable to use a tourniquet to control bleeding, so that the surgical field is clear and the operation is safe.

　　Third, anesthesia:

　　1. For incision and drainage of purulent finger phlebitis or subungual abscess, general finger root nerve block anesthesia is usually used. Adrenaline should not be added to the anesthetic agent to avoid vasoconstriction of the small arteries and resulting obstruction of finger blood supply.

　　2. For incision and drainage of palm interdigital abscess, suppurative tenosynovitis, or hand bursitis, brachial plexus or wrist nerve block anesthesia can be used, or ketamine intravenous anesthesia can be used.

　　Fourth, surgical steps:

　　A longitudinal incision is made on one side of the distal phalanx of the finger. After incising the skin, use hemostats to enter the pus cavity, separate the fibrous bands between the small compartments, release the pus, and place a gauze strip or rubber film for drainage. If the abscess is large or in the shape of a worker, a hemostat can be inserted into the cavity, and a counter-drainage incision can be made on the opposite side of the finger [Figure 1]. However, for infections confined to the palm interdigital space, whether near, middle, or distal phalanx, or towards the central fat pad, a longitudinal incision that does not cross the transverse flexion crease should be used to avoid loss of sensation or necrosis at the finger tip.

　　Untreated purulent finger phlebitis that has developed chronic osteomyelitis of the distal phalanx of the finger can lead to dead bone, causing the purulent finger phlebitis to persist for a long time. For this, a lateral incision at the distal phalanx can be made to expose the phalanx and remove the dead bone; or the terminal osteomyelitis bone can be removed with a small osteotome. The wound is drained with a gauze strip or rubber film [Figure 2].

　　Fifth, precautions during surgery:

　　1. The incision should not exceed 4/5 of the distal segment of the last joint of the finger (6mm from the transverse crease of the last joint) to avoid injury to the flexor tendon sheath and the spread of infection.

　　2. After incising the skin, it is necessary to cut the fibrous bands inside the pus cavity, open the small compartments, and ensure unobstructed drainage.

　　Sixth, postoperative treatment:

　　1. After incision and drainage for hand infection, careful dressing changes should be noted. First, soak the wound in a 1:5000 potassium permanganate solution, while instructing the patient to gently move the affected hand or finger, and use sterile cotton to clean the wound to facilitate the excretion of residual pus in the pus cavity. Then, dry the skin of the affected hand with dry gauze and disinfect it with alcohol. After that, pack it with rubber film or gauze strips for drainage.

　　2. The drainage tube can be removed 3 to 5 days after the operation. After the redness and swelling subside and the pain decreases, finger function exercises should begin to prevent tendinous adhesion, scar contracture, and resulting dysfunction.