jameskim
09-03-2009, 05:27 AM
A 4-year-old boy is brought to the emergency department for a painful and swollen right forearm. He was bitten and scratched by a family cat 2 days ago in the affected area. His temperature is 39.6 C (103.2 F). The right forearm is erythematous, edematous, and tender to touch. Which of the following is the most appropriate antibiotic treatment for this patient? Drug of choice question...
a Ampicillin
b Amoxicillin
c Clindamycin
d Tetracycline
e TMP SMX
a ans is B.
For this case, the patient was bitten by a cat. To initiate appropriate antibiotic treatment, one needs to understand which organisms are most likely causing this infection. In a cat-bite wound, the most common organisms isolated are Pasteurella multocida and Staphylococcus aureus. Among the choices, amoxicillin-clavulanate is the only antibiotic that is effective against both organisms.
P. multocida infection usually manifests within 24-48 hours following the bite or scratch as localized swelling, erythema, tenderness, and serous or sanguinopurulent discharge. Fever, chills, and lymphadenopathy can also occur. Complications include tenosynovitis, osteomyelitis, and septic arthritis. P. multocida is found in the oral flora of 70% to 90% of cats, 25% to 50% of dogs, and a variable percentage in other animals. S. aureus is a common pathogen for cellulitis. It is often found on the skin. In a severe case of animal bite, the pathogens are usually polymicrobial. Therefore, amoxicillin-clavulanate is the treatment of choice; 7-10 days therapy is usually sufficient.
a Ampicillin
b Amoxicillin
c Clindamycin
d Tetracycline
e TMP SMX
a ans is B.
For this case, the patient was bitten by a cat. To initiate appropriate antibiotic treatment, one needs to understand which organisms are most likely causing this infection. In a cat-bite wound, the most common organisms isolated are Pasteurella multocida and Staphylococcus aureus. Among the choices, amoxicillin-clavulanate is the only antibiotic that is effective against both organisms.
P. multocida infection usually manifests within 24-48 hours following the bite or scratch as localized swelling, erythema, tenderness, and serous or sanguinopurulent discharge. Fever, chills, and lymphadenopathy can also occur. Complications include tenosynovitis, osteomyelitis, and septic arthritis. P. multocida is found in the oral flora of 70% to 90% of cats, 25% to 50% of dogs, and a variable percentage in other animals. S. aureus is a common pathogen for cellulitis. It is often found on the skin. In a severe case of animal bite, the pathogens are usually polymicrobial. Therefore, amoxicillin-clavulanate is the treatment of choice; 7-10 days therapy is usually sufficient.