In-Service Exam
Soft Tissue Infection - 2003





A 25-year-old man is brought to the emergency department four hours after being bitten by a raccoon. He has not been previously vaccinated for rabies. In addition to irrigation of the wound, which of the following is the most appropriate management?

The correct response is Option D.

In a patient who has been bitten by a potentially rabid animal and who has not been previously vaccinated, management should include wound care and administration of both rabies immune globulin (RIG) and rabies vaccine. Because rabies incubation periods of more than one year have been reported in humans, the prophylactic regimen should be initiated immediately in any person who has been bitten by an animal with suspected or proven rabies regardless of the length of the delay, as long as clinical signs of rabies are not present. Studies have shown that a regimen of one dose of RIG and five doses of human diploid cell vaccine (HDCV) over a 28-day period is a safe treatment protocol that induces an excellent antibody response.
Immediate, thorough washing of all bite wounds and scratches with soap and water and irrigation with a virucidal agent (such as a povidone-iodine solution) are also important for preventing rabies. Experimental animal studies have shown that thorough wound cleansing alone without other postexposure prophylaxis markedly decreased the likelihood of rabies. In addition, tetanus prophylaxis and measures to control bacterial infection should be administered as indicated. Suturing of large wounds should be based on cosmetic factors and the potential for bacterial infection.
Prophylactic administration of both passive antibody and vaccine is indicated in all exposed patients except for those who have previously received complete vaccination regimens (preexposure or postexposure) with a cell culture vaccine or those persons who have been vaccinated with other types of vaccines and have had documented rabies antibody titers. Instead, these persons should receive the vaccine only. This combination of RIG and vaccine is also recommended for patients who have been exposed to rabies without specifically being bitten.

Rabies postexposure prophylaxis schedule, United States

HDCV=human diploid cell vaccine; PCEC=purified chick embryo cell vaccine; RIG=rabies immune globulin; RVA=rabies vaccine adsorbed; IM=intramuscular.

These regimens are applicable for all age groups, including children.
+ The deltoid area is the only acceptable site of vaccination for adults and older children. For younger children, the outer aspect of the thigh may be used. Vaccine should never be administered in the gluteal area.
¤ Day 0 is the day the first dose of vaccine is administered.
^ Any person with a history of preexposure vaccination with HDCV, RVA, or PCEC; prior postexposure prophylaxis with HDCV, RVA, or PCEC; or previous vaccination with any other type of rabies vaccine and a documented history of antibody response to the prior vaccination.

References
1. Availability of new rabies vaccine for human use. MMWR Morb Mortal Wkly Rep. 1998;47:12, 19.
2. Human rabies Ñ Virginia, 1998. MMWR Morb Mortal Wkly Rep. 1999;48:95-97.

A 21-year-old woman has swelling and edema of the left index finger two days after sustaining a puncture wound to the finger. Which of the following is the most sensitive indicator of bacterial flexor tenosynovitis in this patient?
(A) Diffuse erythema of the finger
(B) Drainage from the wound
(C) Fusiform swelling of the finger
(D) Pain on passive extension of the finger
(E) Tenderness along the flexor tendon sheath

The correct response is Option D.

Tenosynovitis is a bacterial infection within the sheath of the extrinsic flexor tendons of the hand. Suppurative infection of the sheath can develop over time. Classic signs of tenosynovitis include fusiform swelling, partial flexed posturing of the digit, and tenderness along the flexor tendon sheath; however, other inflammatory processes can cause these findings. In contrast, the fourth classic sign, pain with passive extension of the digit, is the most sensitive test for flexor tenosynovitis. Aspiration of the affected tendon sheath will yield purulent drainage. Diagnosis can be confirmed with Gram's stain.

In patients with established tenosynovitis, the most appropriate management is surgical irrigation and/or drainage of the tendon sheath. This is best accomplished with a proximal incision at the level of the A1 pulley and a distal incision at the distal flexor crease; the fibroosseous canal is then irrigated copiously. In patients with more extensive infection, open drainage and debridement may be required.

Drainage from a finger wound is more likely to be caused by local wound infection than by tenosynovitis.

References
1. Juliano PT, Eglseder WA. Limited open sheath irrigation in the treatment of pyogenic flexor tenosynovitis. Ortho Res. 1991;20:1065-1069.
2. Schall SB, Va-Rose T, Holtom P, et al. Tissue pressures in pyogenic flexor tenosynovitis of the finger. J Bone Joint Surg. 1996;78B:793-795.

A 49-year-old man with type 2 diabetes mellitus has had a "sausage" appearance of the left long finger from the metacarpophalangeal joint to the fingertip for the past two days. The finger is held in flexion at rest. On physical examination, there is tenderness along the volar aspect of the finger, and the patient has pain with passive extension.

Which of the following is the most likely diagnosis?

(A) Cellulitis
(B) Felon
(C) Osteomyelitis
(D) Paronychia
(E) Tenosynovitis

The correct response is Option E.

The most likely diagnosis is tenosynovitis, an infection involving the gliding surface of the flexor tendon sheath that typically develops following a puncture wound. Staphylococcus aureus is the most likely causative organism. The four essential signs of tenosynovitis are fusiform swelling, partial flexed posturing of the digit, tenderness along the flexor tendon sheath, and pain with passive extension of the digit.

Cellulitis is a common superficial infection that typically affects the dorsal aspect of the hand and is characterized by erythema, edema, and lymphangitis. Beta-hemolytic streptococcus is most frequently associated.

Felons are infections of the pulp space (which is compartmentalized by septa) typically caused by Staphylococcus aureus. Although tenosynovitis may develop in a patient with an advanced felon, the infection is more likely to be localized at the pulp initially, and the patient would have throbbing pain, especially when the finger is placed in a dependent position.

Patients with osteomyelitis have localized pain, swelling, and erythema along the course of one of the long bones of the hand. This condition often develops secondary to localized infection by hematogenous spread.

In patients with paronychia, the structures surrounding the proximal and lateral nail become infected. This condition is characterized by pain, especially in the region of the nail fold, and erythema. Staphylococcus aureus is the most frequently identified cause of acute paronychia, and Candida albicans is most likely to cause chronic paronychia.

Reference
1. Neviaser RJ. Acute infections. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;2:1033-1047.

A 55-year-old woman has had pain, swelling, and erythema of the left arm for the past 24 hours. She underwent mastectomy and axillary lymph node dissection on the left four years ago. On examination, she is afebrile. Laboratory studies show a leukocyte count that is within normal limits.

Which of the following is the most appropriate management?

(A) Lymphatic massage
(B) Application of a compression bandage and elevation of the extremity
(C) Topical application of an antibiotic
(D) Intravenous administration of an antibiotic
(E) Incision and drainage

The correct response is Option D.

In this patient who has had the spontaneous onset of cellulitis of the arm after undergoing axillary lymph node dissection, the most appropriate management is intravenous administration of an antistreptococcal antibiotic. Fever and leukocytosis are typically associated with cellulitis but are not required to make the diagnosis, as many of these patients will be afebrile and will not have an increased leukocyte count or absolute neutrophil count on serologic testing. Anti-streptolysin O titer may be positive.

Although lymphatic massage and compression and elevation of the extremity are useful in controlling the lymphedema associated with lymph node dissection, these measures will not treat cellulitis. Antibiotic therapy should not be based on the results of blood or tissue aspirate cultures because these often do not yield any growth. Topical application of an antibiotic will not effectively treat cellulitis. Incision and drainage of the affected site is not indicated.

References
1. Calkins ER. Nosocomial infections in hand surgery. Hand Clin. 1998;14:531-545.
2. Simon MS, Cody RL. Cellulitis after axillary lymph node dissection for carcinoma of the breast. Am J Med. 1992;93:543-548.

An otherwise healthy 44-year-old woman has chronic, persistent paronychia of the index finger. Administration of oral and topical antifungal agents has not resulted in improvement of symptoms. Which of the following is the most appropriate management?

(A) Incision and drainage
(B) Removal of the nail plate
(C) Eponychial marsupialization
(D) Obliteration of the nail matrix
(E) Amputation of the fingertip

The correct response is Option C.

This patient has chronic paronychia, which is a recurrent abscess beneath the eponychial edge of the fingernail associated with repeated exposure to a moist environment. In patients with this condition, Candida albicans is the most frequently cultured organism. Chronic paronychia can evolve following an acute episode if drainage of the abscess is inadequate or inappropriate antimicrobial agents are prescribed. Removal of a segment of nail plate is indicated in patients with acute paronychia if there is drainage beneath the plate.

In a patient who has paronychia that appears to be caused by a fungal organism, management should focus on administering oral and topical antifungal agents, such as itraconazole and ketoconazole, and minimizing the moist environmental conditions that have predisposed the patient to the infection.

If the infection does not respond to treatment, radiographs should be obtained to determine bony involvement. In addition, biopsy specimens and cultures of soft tissue and/or bone may be indicated to identify the pathology of the condition, as the underlying cause may be a misdiagnosed malignant tumor. If radiographs, biopsy specimens, and cultures show no disease, appropriate management is excision of the thickened dorsal nail roof (ie, marsupialization), typically a crescent-shaped piece with a width of 3 to 5 mm.

Simple repeat incision and drainage alone will not prevent recurrence. Obliteration of the nail matrix or amputation of the fingertip will not address the symptoms.

References
1. Jebson PJ. Infections of the fingertip. Hand Clin. 1998;14:547-555.
2. Zook EG, Brown RE. The perionychium. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;2:1353-1380.