(A) Peptostreptococcus sp.
(B) Pseudomonas aeruginosa
(C) Staphylococcus epidermidis
(D) Streptococcus faecalis
(E) Viridans streptococcus

The correct response is Option E.

Staphylococcus aureus and viridans streptococcus are the two most commonly isolated organisms in hidradenitis suppurativa. As a result, initial management should include empiric administration of antibiotics effective against these organisms until the results of cultures are received.

Hidradenitis suppurativa is a condition that is poorly understood but is thought to result from chronic infection of the apocrine sweat glands. Although the axillae are affected most commonly, the perineum, groin, and genitalia may also be involved. Extensive scar tissue and fistula tracts develop over time, and the condition becomes progressively more difficult to treat. In patients with hidradenitis, appropriate management is application of warm compresses, incision and drainage of the appropriate areas, and administration of antibiotics. Patients with more severe cases should undergo excision of the involved skin and subcutaneous tissue followed by coverage with a local flap or skin graft. Investigational studies of a method of immunotherapy, based on the staphylococcal phage lysate vaccine, have shown promising results in patients with chronic hidradenitis suppurativa.

References
1. Angel MF. Beneficial effects of staphage lysate in treatment of chronic recurrent hidradenitis suppurativa. Surg Forum. 1987;38:111.
2. Harrison BJ. Recurrence after surgical treatment of hidradenitis suppurativa. Br Med J. 1987;294:487.
3. Ramasastry SS. Surgical management of massive perianal hidradenitis suppurativa. Ann Plast Surg. 1985;15:218.
4. Watson JD. Hidradenitis suppurativa: a clinical review. Br J Plast Surg. 1985;38:567.

A 6-year-old boy with sudden onset of fever and septic shock has disseminated intravascular coagulation. Physical examination shows hemorrhagic necrosis of the skin of the upper and lower extremities. Which of the following is the most likely causative organism?

(A) Escherichia coli
(B) Group A beta-hemolytic streptococcus
(C) Neisseria meningitidis
(D) Staphylococcus aureus
(E) Varicella-zoster virus

The correct response is Option C.

This 6-year-old boy has purpura fulminans, an uncommon illness that typically affects young children but can also occur in adults. Purpura fulminans often develops in association with a predisposing condition. It manifests as severe hemorrhage and necrosis of skin associated with disseminated intravascular coagulation. Affected patients have petechial rashes, which progress to confluent areas of ecchymosis, and then to necrotic, hard, full-thickness eschar. Bilateral symmetric gangrene of the extremities necessitates amputation in as many as 20% of patients. Reconstructive procedures, including free tissue transfer, are frequently required to resurface necrotic areas and salvage extremities with exposed joints. Septic shock and organ failure may also result. Mortality rates have been reported to be as high as 60%.

Purpura fulminans is associated with endotoxin-producing bacteria. Although Neisseria meningitidis is the most common causative organism, Streptococcus pneumoniae, Haemophilus influenzae, and Rickettsia have also been implicated. The mechanism of this condition is believed to be liposaccharide-mediated endothelial damage caused by bacteria, leading to decreased serum levels of proteins C and S. Skin necrosis results from a low-flow coagulative state and microemboli. Management of affected patients includes general hemodynamic support, intravenous administration of an appropriate antibiotic, wound care, eventual soft-tissue reconstruction, and amputation when necessary.

References
1. Andreason TJ, Green SD, Childers BJ. Massive infectious soft tissue injury: diagnosis and management of necrotizing fasciitis and purpura fulminans. Plast Reconst Surg. 2001;107:1025-1034.
2. MacLennan SE, Kitzmiller WJ, Yakuboff KP. Free tissue transfer for limb salvage in purpura fulminans. Plast Reconstr Surg. 2001;107:1437-1442.

A construction worker has an abscess of the palm of the nondominant hand after sustaining a puncture wound to the palm. In this patient, the midpalmar space is defined by which of the following boundaries?

(A) Flexor tendons, abductor pollicis muscle, superficial aponeurosis, and septum from the second metacarpal bone to the flexor digitorum profundus sheath
(B) Flexor tendons, metacarpal bone and interosseous fascia, septum from the third metacarpal to the flexor digitorum profundus sheath, and hypothenar eminence
(C) Flexor tendons, superficial palmar aponeurosis, and thenar and hypothenar eminences
(D) Flexor tendons, thenar eminence, septum from the second metacarpal bone to the flexor digitorum profundus tendon, and superficial aponeurosis
(E) Septum from the first metacarpal bone to the superficial aponeurosis, septum from the third metacarpal to the flexor tendon sheath, and lateral and medial edges of the abductor pollicis muscle

The correct response is Option B.

The midpalmar space is one potential site of infection of the palm; others include the subcutaneous tissue, tendon sheaths, and thenar and hypothenar eminences. The midpalmar space is located deep to the flexor tendon. It extends dorsally to the fascia over the second and third volar interossei and the third and fourth metacarpals.

The midpalmar space is bordered radially by a fascial septum extending from the third metacarpal to the flexor sheath of the flexor digitorum profundus tendon of the long finger, and ulnarly by the fascia of the hypothenar musculature. The proximal margin of the midpalmar space is a thin layer of fascia that lies just distal to the carpal canal. The distal margin of the midpalmar space is bordered by vertical septa of the palmar fascia, which extend almost to the web spaces.

In patients with infection of the midpalmar space, diagnosis is often delayed. Affected patients typically exhibit swelling of the dorsal aspect of the hand, loss of palmar concavity, and difficulty extending and flexing the fingers. Marked tenderness in the midpalmar area is characteristic, and cellulitis is often associated.

The thenar space is located radial to the vertical septum between the third metacarpal and the flexor digitorum profundus tendon of the long finger; it extends to the radial edge of the abductor pollicis brevis tendon. The hypothenar space contains the hypothenar muscles and is enveloped within the fascia of these muscles. It is bordered radially by a fascial septum extending from the fifth metacarpal bone to the palmar fascia.

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 47-year-old woman has a low-grade fever, chills, and pain and swelling of the proximal interphalangeal joint of the index finger. On examination, active and passive motion of the joint produces pain. There is no lymphangitis or lymphadenopathy. Which of the following is the most likely causative organism?

(A) Eikenella corrodens
(B) Neisseria gonorrhoeae
(C) Serratia marcescens
(D) Staphylococcus aureus
(E) Viridans streptococcus

The correct response is Option D.

In this patient who has septic arthritis affecting the proximal interphalangeal joint of the index finger, the most likely cause is infection with Staphylococcus aureus organisms. Staphylococcus aureus is an anaerobic gram-positive coccus that is present on the skin and is a frequent cause of skin and soft-tissue infections. It is the most common cause of septic arthritis of the hand and wrist.

Eikenella corrodens, an anaerobic gram-negative rod, is present in the human mouth and is more likely to be cultured from a human bite wound.

Septic arthritis resulting from Neisseria gonorrhoeae is more likely to occur in young men who are sexually active. Affected patients typically have a history of migratory polyarthralgia.

Serratia species are a frequent cause of infection in persons who abuse intravenous drugs as well as patients with diabetes mellitus or immune system compromise.

Streptococcus species, including viridans streptococcus, are the second most common causative organism in patients with septic arthritis of the hand.

References
1. Murray PM. Septic arthritis of the hand and wrist. Hand Clin. 1998;14:579-587.
2. Neviaser RJ. Acute infections. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:1033-1047.

A 50-year-old man has had the fingernail deformity shown in the photograph above for the past year. There is no history of trauma to the finger. Which of the following is the most appropriate management?

(A) Topical administration of neomycin ointment twice daily
(B) Oral administration of ciprofloxacin 400 mg twice daily
(C) Oral administration of terbinafine 250 mg daily
(D) Resection of the involved sterile matrix and grafting from the matrix of the great toe
(E) Surgical removal of the nail plate and stenting of the eponychial fold with nonadherent gauze

The correct response is Option C.

This patient has a dystrophic nail resulting from a fungal infection (onychomycosis). The diagnosis of onychomycosis can be confirmed by positive findings on fungal culture. Fungal infections are the underlying cause of dystrophic nails
in approximately 50% of affected patients; the remaining 50% are caused by other factors, including psoriasis, lichen planus, and trauma. Although they are more common in the foot, fungal infections can cause functional and aesthetic deformities in the fingernails.

In the past, long-term administration of antifungal agents was recommended; however, this treatment course was associated with significant toxicity, requiring monitoring of hepatic function, and often disappointing results. More recently, terbinafine and itraconazole have offered new treatment options. This agents are administered for six weeks, and hepatic function is monitored only in those patients who have a history of hepatitis, liver disease, or heavy alcohol use. However, adverse effects associated with terbinafine use include Stevens-Johnson syndrome, neutropenia, hepatotoxicity, hepatic failure, erythema multiforme, toxic epidermal neurolysis, and anaphylaxis. In addition, terbinafine is far more costly than previously used antifungal agents.

Topical or oral administration of antibiotics would not be expected to improve this fungal infection. In addition, topical antibiotics may aggravate the nail matrix. Resection of the sterile matrix and replacement with a graft is associated with a high incidence of recurrence and morbidity. Removal of the nail would not eliminate the fungal infection within the underlying matrix.

References
1. Arca E, Tastan HB, Akar A, et al. An open, randomized, comparative study of oral fluconazole, itraconazole and terbinafine therapy in onychomycosis. J Dermatol Treatment. 2002;13:3-9.
2. Concannon MJ. Infections of the hand. In: Common Hand Problems in Primary Care. Philadelphia, Pa: Hanley & Belfus, Inc; 1999;7:127-132.
3. Crawford F, Young P, Godfrey C, et al. Oral treatments for toenail onychomycosis: a systematic review. Arch Dermatol. 2002;138:811-816.
4. Haugh M, Helou S, Boissel JP, et al. Terbinafine in fungal infections of the nails: a meta-analysis of randomized clinical trials. Br J Dermatol. 2002;147:118-121.

A 34-year-old man has had pain and swelling of the long and ring fingers for the past three days. On physical examination, there is a sausage-like appearance of the fingers. The patient has pain on passive stretch of the fingers, and there is tenderness over the flexor tendon sheaths. Radiographs show swelling of the soft tissues.

In addition to intravenous administration of antibiotics, which of the following is the most appropriate management?

(A) Needle aspiration of the flexor tendon sheaths
(B) Incision into the fingers
(C) Incision into the joints
(D) Incision into the palm
(E) Opening and irrigation of the flexor digital sheath

The correct response is Option E.

This 34-year-old man has findings consistent with advanced flexor tenosynovitis. The diagnosis can be made by the presence of one or more of Kanavel’s four signs (fusiform swelling, partial flexed posturing of the finger, tenderness over the flexor tendon sheath, and pain with passive extension of the finger). This patient exhibits three of the diagnostic signs, indicating an advanced disease course. In addition to intravenous administration of antibiotics, the most appropriate management is opening and irrigation of the flexor tendon sheath. The surgeon should make an incision into the palm that is sufficiently wide to allow for access to and visualization of the proximal aspect of the A1 pulley. Another incision is made distally to allow access to the A4 and A5 pulleys. If necessary, the incisions can be extended distally and/or proximally to treat infected, necrotic tissue.

In patients with advanced flexor tenosynovitis, the flexor digital sheath is typically distended with purulent material. A plastic irrigation catheter is inserted at the level of the A1 pulley and threaded distally into the sheath to allow for irrigation beyond the A5 pulley. This technique will facilitate complete decompression of the sheath without sacrificing
the pulleys. Irrigation can be provided via the catheter continuously for as long as 24 hours, depending on the severity of infection.

Needle aspiration is useful in establishing a diagnosis of or treating early tenosynovitis (characterized by the presence of only one or two of Kanavel’s signs) or as initial treatment during pregnancy. Simple incision into the finger, joint, or palm will not address in the infection of the flexor tendon sheath.

References
1. Boles DS, Schmidt CC. Pyogenic flexor tenosynovitis. Hand Clin. 1998;14:567-576.
2. McGrath MH. Infections of the hand. In: McCarthy JG, ed. Plastic Surgery. Philadelphia, Pa: WB Saunders Co; 1990;8:5529-5554.
3. Neviaser R. Acute infections. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:1033-1046.

An otherwise healthy 48-year-old nurse is brought to the emergency department because she has intense pain in the right lower extremity after sustaining a minor abrasion of the right knee. She has undergone evaluation twice within the past 48 hours for pain disproportionate to the level of injury. Temperature is 38.8 C (102 F) and blood pressure is 70/50 mmHg. On examination, the extremity is warm, swollen, and erythematous. There is a bluish blister at the site of injury. Laboratory studies show an increased leukocyte count, decreased platelet count, increased serum creatinine level, and increased international normalized ratio (INR). Radiographs show no abnormalities.

Which of the following is the most likely diagnosis?

(A) Clostridium necrotizing fasciitis
(B) Cutaneous anthrax
(C) Pseudomonas ecthyma gangrenosum
(D) Staphylococcal cellulitis
(E) Streptococcal toxic shock syndrome

The correct response is Option E.

This 48-year-old nurse has findings consistent with streptococcal toxic shock syndrome caused by invasive infection with Streptococcus organisms. This condition is characterized by pain disproportionate to the level of injury. Affected patients typically have other minor symptoms, in addition to pain, and have been known to seek treatment frequently before the correct diagnosis is established. Streptococcal toxic shock syndrome is confirmed by the presence of coagulation difficulties and hepatic and renal abnormalities.

Clostridial necrotizing fasciitis has symptoms similar to streptococcal toxic shock syndrome but is differentiated by subcutaneous emphysema and air in the tissues on radiographs.

With anthrax contamination, primary routes of inoculation are cutaneous and inhalational. Cutaneous anthrax is characterized by a single lesion that initially resembles an insect bite but then becomes ulcerated. Skin trauma is not associated.

Pseudomonas ecthyma gangrenosum is an infection that demonstrates rapid progression and is frequently fatal. It occurs in patients with febrile neutropenia, and is often a complication of chemotherapy administered for lymphoreticular malignancies.

Although staphylococcal cellulitis is not associated with systemic manifestations, patients with staphylococcal toxic shock syndrome can have failure of multiple organ systems.

References
1. Stevens DL. Invasive streptococcal infections. J Infect Chemother. 2001;7:69-80.
2. Trent JT, Kirsner RS. Diagnosing necrotizing fasciitis. Adv Skin Wound Care. 2002;15:135-138.

A 40-year-old man has a painful, fluctuant abscess over the dorsal aspect of the left hand at the level of the metacarpophalangeal joints. On physical examination, the index finger is abducted away from the long finger. This abscess most likely courses through which of the following anatomic sites?

(A) Extensor tendon sheath
(B) Flexor tendon sheath
(C) Palmar bursa
(D) Palmar fascia
(E) Parona’s space

The correct response is Option D.

This patient has a collar button abscess, which communicates from the volar web space to the dorsal aspect of the hand via the palmar fascia or lumbrical canal. Finger abduction is a characteristic finding. Appropriate management is drainage of the abscess using a combined volar and dorsal approach.

The extensor tendons do not lie within sheaths on the dorsal aspect of the hand.

Infection of the flexor tendon sheath is known as flexor tenosynovitis. This condition is diagnosed by the presence of one or more of Kanavel’s signs, including fusiform swelling, partial flexed posturing of the finger, tenderness over the flexor tendon sheath, and pain with passive extension of the finger. Finger abduction is not associated.

Patients with infection of the palmar bursa have a painful prominence in the palm without finger abduction.

Parona’s space lies between the pronator quadratus and flexor digitorum profundus tendons. It communicates with the flexor tendon sheaths to the thumb and small finger (radial and ulnar palmar bursa) and the midpalmar space. Infection within this space is characterized by painful swelling over the volar aspect of the wrist that occurs proximal to the flexion crease of the distal wrist.