In-Service Exam
Soft Tissue Infection - 2002





A 23-year-old woman has the onset of fever, generalized weakness, and erythroderma of the extremities eight hours after undergoing septorhinoplasty for reduction of a fracture of the nasal bones. Intranasal splints and packing were left in place following the procedure. These findings are most consistent with which of the following?

(A) Acute gastroenteritis
(B) Kawasaki disease
(C) Stevens-Johnson syndrome
(D) Toxic shock syndrome
(E) Urosepsis

The correct response is Option D.

This patient's findings are most consistent with toxic shock syndrome. This condition should be suspected in any patient who has fever, hypotension, and erythroderma following surgery, trauma, or infection of structures related to the skin or nares. Symptoms include a temperature greater than 38.9%C (102%F), a diffuse macular rash, and a systolic blood pressure of less than 90 mmHg in adults or less than the fifth percentile for children younger than 16 years. Syncope and orthostatic hypotension are also common. Desquamation of the palms and soles typically occurs one to two weeks after the onset of illness. Appropriate management should include supportive treatment for multisystem organ involvement, antibiotics effective against Staphylococcus aureus, and identification and treatment of the focus of bacterial toxin production. Although the Staphylococcus organisms that produce toxic shock syndrome toxin typically do not produce purulent wounds and the surgical wound may appear normal, an undrained focus of infection may be present in the wound. Therefore, the wound should be debrided to locate any potential source of toxin-producing organisms and to provide tissue for bacterial culture.

Acute gastroenteritis is associated with the abrupt onset of hypotension and abdominal symptoms such as nausea and diarrhea. Erythroderma is not an associated finding.

Kawasaki disease is a multisystem disease typically seen in children younger than 7 years and characterized by prolonged fever, lymphadenitis, conjunctivitis, and erythema of the mucous membranes. Thrombocytosis and desquamation of the distal digits occur during the recovery phase. Hypotension is rare. Infection with Staphylococcus aureus and/or Streptococcus pyogenes is not associated.

Patients with Stevens-Johnson syndrome have a systemic, widespread rash that also affects the mucous membranes. This condition can result from infection, illness, or an allergic reaction to medication. Systemic symptoms are typically severe.

In patients with urosepsis, the onset of septic shock can be typically distinguished from toxic shock syndrome by the absence of erythroderma. Profuse watery diarrhea is uncommon in patients with urosepsis but occurs frequently in patients with toxic shock syndrome.

References
1. Berdoll MS, Chesney PJ. Toxic Shock Syndrome. Boston, Mass: CRC Press; 1991:33-45.
2. Peck GC, Goldwyn RM. Unfavorable results in rhinoplasty. In: Goldwyn RM, ed. The Unfavorable Result in Plastic Surgery. Boston, Mass: Little, Brown & Co; 1984;2:539-561.

A 33-year-old man has the onset of necrosis after sustaining a brown recluse spider bite. Dapsone 50 mg twice daily is prescribed for the next 14 days. Which of the following adverse effects is most likely to be seen in this patient?

(A) Diarrhea
(B) Diplopia
(C) Headache
(D) Hemolysis
(E) Peripheral neuropathy

The correct response is Option D.

The brown recluse spider (Loxosceles reclusa) is one of two species of North American spider capable of envenomation. It is generally found throughout the southern United States. This spider is believed to be nocturnal but may also be active during the day; it does not weave a web. Features include long slender legs and a distinctive fiddle-shaped marking on its dorsal cephalothorax. Both male and female brown recluse spiders are venomous.

Most patients are unaware that they have been bitten by this spider until pain develops or the wound becomes noticeable. Blistering, ischemia, and ulceration may be seen and can ultimately lead to necrosis.

Conservative treatment with administration of dapsone 100 mg daily for 14 days is advocated as the injury is often more extensive than initially thought. There is no antivenin to brown recluse spider venom. Dapsone is a leukocyte inhibitor that has both bacteriostatic and bacteriocidal properties and is frequently used in the treatment of leprosy. Hemolysis is the most common adverse effect of dapsone therapy. Because of the risk for hemolysis and other hematologic side effects, including methemoglobinemia, blood counts should be measured weekly. In addition, dapsone should not be administered to patients who have glucose-6 phosphate dehydrogenase deficiency.
Diarrhea, diplopia, headache, and peripheral neuropathy are not complications of dapsone therapy.

References
1. Burch JM, Franciose RJ, Moore EE. Trauma. In: Schwartz SI, ed. Principles of Surgery. New York, NY: McGraw-Hill, Inc; 1999:212-213.
2. Drug Facts and Comparisons 2000. Saint Louis, Mo: Facts & Comparisons, Inc; 1999:1621.
3. Kemp ED. Bites and stings of the arthropod kind: treating reactions that can range from annoying to menacing. Postgrad Med. 1998;103:88-90.
4. Physicians' Desk Reference. Montvale, NJ: Medical Economics Co; 2000:638.
5. Wright SW, Wrenn KD, Murray L, et al. Clinical presentation and outcome of brown recluse spider bite. Ann Emerg Med. 1997;30:28-32.

An otherwise healthy 27-year-old man sustains a scorpion sting on a camping trip. Which of the following is the most appropriate management?

(A) Application of cold compresses
(B) Application of a tourniquet
(C) Administration of diazepam
(D) Administration of scorpion antivenin
(E) Debridement of the affected area

The correct response is Option A.

Because scorpion stings are typically self-limiting in adults, management should be limited to observation and application of cold compresses. Six closely related species of scorpion found in the southwestern United States cause medically significant injuries resulting from a sting. These species are typically 1 to 7 cm long and yellow-brown in color, possibly with vertical bands. The venom is neurotoxic, resulting in activation of the autonomic nervous system and depolarization of the neuromuscular junctions. Affected patients have intense localized pain and hyperesthesia; there is severe pain with light tapping over the area of the wound. Other symptoms seen in patients who sustain scorpion stings include blurred or diminished vision, strabismus, dyspnea, wheezing, dysphagia, urinary or fecal incontinence, opisthotonos, fever, and involuntary muscle contractions.

Hospital admission is recommended for children who have scorpion stings because envenomation is much more dangerous than in adults. Appropriate pediatric management includes airway control, sedation, cardiac monitoring for potential arrhythmias, and administration of calcium gluconate for treatment of muscle spasms. Narcotic agents should not be administered as they may exacerbate the neurotoxic effects. Scorpion antivenin is available for use in Arizona.

The use of tourniquets is not recommended in patients with scorpion stings. Debridement is not necessary because scorpion venom has only localized adverse effects on soft tissue.

References
1. Burch JM, Franciose RJ, Moore EE. Trauma. In: Schwartz SI, ed. Principles of Surgery. New York, NY: McGraw-Hill, Inc; 1999:213.
2. Kemp ED. Bites and stings of the arthropod kind: treating reactions that can range from annoying to menacing. Postgrad Med. 1998;103:88-90.

A 33-year-old snake handler has diffuse swelling of the left hand and forearm after being bitten by a pit viper. The venom was directly injected into the skin and subcutaneous tissue of the forearm. When establishing a diagnosis of compartment syndrome in this patient, which of the following is the earliest clinical finding?

(A) Accentuation of pain by passive muscle stretching
(B) Diminished sensation in the affected compartment
(C) Obliteration of distal pulses by compartment swelling
(D) Persistent, worsening pain
(E) Tenseness on palpation of the compartments of the forearm

The correct response is Option A.

This patient has compartment syndrome due to a snake bite. Pain is the hallmark of compartment syndrome and is accentuated by passive stretching of the involved muscle compartment, which is the most consistent early sign. Patients with injuries of the upper and lower extremities should be closely monitored for the presence of muscle, nerve, and tissue ischemia. However, compartment syndrome occurring in conjunction with a pit viper or other snake bite is often worse than other types of compartment syndrome. Because the venom is injected directly into the tissues, tissue destruction occurs rapidly, leading to the immediate onset of edema, ecchymosis, and swelling.

Measurement of compartment pressures is an important step in the diagnosis of compartment syndrome, especially in patients who have sustained head trauma or spinal cord injuries. Decompressive fasciotomy should be performed in normotensive patients when compartment pressures are greater than 30 mmHg and the duration of symptoms is longer than eight hours or is unknown or the patient is unconscious or uncooperative. Patients with hypotension and compartment pressures greater than 20 mmHg should also undergo surgery within six hours.

In some patients with compartment syndrome, central or peripheral sensory deficits or late nerve ischemia may preclude the presence of pain as a diagnostic finding.

In compartment syndrome, distal pulses may still be present. The affected extremity may appear cyanotic, pale, or normal. Sensation may be normal or diminished.

Tenseness and tenderness of the closed compartments are nonspecific findings that are not necessarily associated with ischemic tissue damage.

References
1. Garfin SR, Mubarak SJ. Treatment of rattlesnake bites. J Hand Surg. 1980;5A:619-621.
2. Mubarak SJ, Hargens AR. Acute compartment syndromes. Surg Clin North Am. 1983;63:539-565.
3. Rowland SA. Fasciotomy: the treatment of compartment syndrome. In: Green DP, ed. Operative Hand Surgery. 3rd ed. New York, NY: Churchill Livingstone, Inc; 1993;2:661-694.
4. Schneider JM, Roger DJ, Uhl RL. Bilateral forearm compartment syndromes resulting from neuroleptic malignant syndrome. J Hand Surg. 1996;21A:287-289.

In a patient undergoing medicinal leech therapy for management of venous congestion following thumb replantation, the most appropriate adjunctive treatment is antibiotic prophylaxis against which of the following organisms?

(A) Aeromonas hydrophila
(B) Eikenella corrodens
(C) Histoplasma capsulatum
(D) Pasteurella multocida
(E) Staphylococcus aureus

The correct response is Option A.

Adjunctive treatment in this patient should include antibiotic prophylaxis against Aeromonas hydrophila organisms. This is a symbiotic bacteria found in the intestines of medicinal-grade leeches of the Hirudo medicinalis species, which can be applied to flaps or replanted limbs in order to alleviate venous congestion. The Aeromonas bacteria produces digestive enzymes that act to break down hemoglobin within the intestines of the leech. However, patients with devitalized vascular tissue are particularly susceptible to infection with this gram-negative organism. Affected patients will develop a rapidly progressive infection with gas in the soft tissues that can resemble clostridial myonecrosis. Appropriate management consists of debridement of the affected area and administration of aminoglycoside, trimethoprim-sulfamethoxazole, or a third-generation cephalosporin.

Eikenella corrodens is a facultative anaerobic gram-negative rod typically associated with human bite wounds. Penicillin or ampicillin is recommended for treatment. Histoplasma capsulatum is a fungus that results in arthralgia and arthritis in affected patients. Administration of amphotericin B is indicated. Pasteurella multocida is an anaerobic gram-negative bacillus, typically associated with cat bites and best treated with penicillin or amoxicillin with clavulanate. Staphylococcus aureus is an anaerobic gram-positive coccus present on the skin that is a frequent cause of skin and soft-tissue infections.

References
1. Brody GA, Maloney WJ, Hentz VR. Digital replantation applying the leech Hirudo medicinalis. Clin Orthop. 1989;245:133-137.
2. Lowen RM, Rodgers CM, Ketch LL, et al. Aeromonas hydrophila infection complicating digital replantation and revascularization. J Hand Surg. 1989;14A:714-718.