1 infec 83 - tabish60102

[ArchivalUser]

A 45-year-old woman was bitten on her right hand by her house cat during somewhat aggressive play. There was a small amount of bleeding from two puncture wounds on the palm. The patient promptly washed the wound and applied antiseptic.

One day later, she developed erythema at the wound site, which immediately began to spread circumferentially, most markedly toward the wrist. The wound is now quite painful, and the patient notes slight chilling and possible fever. She developed hives and generalized pruritus when given amoxicillin for a sore throat 4 years ago.

On physical examination, temperature is 37.2 °C (99 °F), pulse rate is 102/min, respiration rate is 18/min, and blood pressure is 162/102 mm Hg. There is swelling, erythema, and tenderness of the thenar eminence of the right hand with irregular spreading of the erythema that is now proximal to the wrist. Nondraining puncture marks are evident. Cardiopulmonary examination is unremarkable.

Laboratory Studies
Hemoglobin

12.9 g/dL (129 g/L)
Hematocrit

38.9%
Leukocyte count

14,750/µL (14.7 × 109/L) with 95% neutrophils and 5% lymphocytes
Blood urea nitrogen

22 mg/dL (7.86 mmol/L)
Serum creatinine

1.3 mg/dL (114.95 µmol/L)
Serum electrolytes

Normal

Which of the following is the most appropriate outpatient treatment regimen for this patient?

A Doxycycline
B Ciprofloxacin
C Trimethoprim“sulfamethoxazole plus clindamycin
D Cephalexin plus metronidazole
E Amoxicillin“clavulanate

[ArchivalUser]

aa

[ArchivalUser]

ee

[ArchivalUser]

E) human/pet bite

[ArchivalUser]

ccc

[ArchivalUser]

HUMAN BITE EEE
PET BITE CCC

[ArchivalUser]

Correct Answer = C)
Key Point
The most appropriate treatment for a cat bite in a patient with a penicillin allergy is trimethoprim“sulfamethoxazole plus clindamycin.

The most likely pathogens are Pasteurella multocida, Staphylococcus aureus, and Streptococcus pyogenes. Combination therapy with trimethoprim“sulfamethoxazole plus clindamycin provides coverage for most of these organisms with the possible exception of methicillin-resistant S. aureus and is the most appropriate choice for this patient, who has a convincing history of a penicillin allergy. No single oral drug would provide adequate coverage for a penicillin-allergic patient. Some experts might also add an initial dose of vancomycin because of the increasing frequency of methicillin-resistant S. aureus in some communities.

Doxycycline, ciprofloxacin, and cephalexin plus metronidazole would not provide reliable coverage for P. multocida or the other possible etiologic agents. Amoxicillin“clavulanate is contraindicated in a patient with a penicillin allergy