Score - Infection Flashcards
A 29-year-old woman with uncontrolled type 2 diabetes and a known penicillin allergy reports to clinic for evaluation of a wound. Her random blood glucose on admission is elevated, with a value of 135 mg/dL. She reports that a family member bought a new pet cat that bit her on the right foot. Although there was initially blood dripping from the wound, she did not consider the possibility of infection. She washed the wound with water and lightly bandaged it. Because more than 2 days have passed with increased tenderness and no signs of healing, the woman decided to seek medical care. On physical examination of her foot and ruling out the need for surgical intervention, she is diagnosed with cellulitis. In addition to determining the appropriateness of tetanus and rabies prophylactic therapy, which of the following is the best next step in management?
Doxycycline and trimethoprim/sulfamethoxazole is best.
This treatment has been shown to yield results comparable to those of the traditional therapy (ie, amoxicillin and clavulanate or moxifloxacin) for patients with a penicillin allergy. Although amoxicillin and clavulanate may be an acceptable treatment for many patients, it is not the best choice for this patient with a known allergy to penicillin. Observation and close follow-up may be considered for immunocompetent patients with a minor dog or human bite provided it is not located on the feet, hands, or genitals. However, this woman has a cat bite. Cat bites are more dangerous, because the sharper teeth of cats can inoculate oral flora deep into human tissues. Because she has been diagnosed with cellulitis, antibiotic therapy in addition to possible tetanus and rabies prophylaxis treatment is warranted. Fluconazole is an antifungal medication with excellent activity against yeast. Therefore, it is not the appropriate treatment for bacterial cellulitis that results from a cat bite. Although insulin may be used to address the woman’s hyperglycemia, it is not the correct option for treating a cat bite. Discharging her would be inappropriate until the correct therapy for her condition is provided.
An 82-year-old male with a past medical history of insulin-dependent diabetes mellitus and recurrent episodes of cellulitis presents to the Emergency Department with a two-day history of rapidly progressive left foot erythema, pain, and tender induration. He has a fever of 102°F, with erythema and multiple bullae with purulent drainage over the dorsum of the left foot. Your workup reveals leukocytosis, no evidence for abscess and no evidence of osteomyelitis. What is the best treatment plan for this patient?
Admit the patient for IV ampicillin/sulbactam and vancomycin.
The patient has a fever and cellulitis with purulent drainage and bullae. The recommendation for patients with systemic symptoms and purulent drainage is for hospitalization and broad-spectrum antibiotic treatment. In patients with recurrent cellulitis, it is recommended that you cover MRSA with vancomycin.
A 17-year-old girl presents to the emergency department 3 days after sustaining a dog bite on her arm. She has no medical problems and is allergic to penicillin. Her forearm near the bite is warm with localized erythema but no fluctuance or crepitus. In addition to tetanus prophylaxis, which antibiotic regimen should she receive?
Levofloxacin and metronidazole
This combination provides sufficient coverage of Pasteurella multocida and anaerobic bacteria. Metronidazole and clindamycin only provide anaerobic coverage; they do not provide action against P multocida. While amoxicillin-clavulanate would be the best option, this patient is allergic to penicillin. TMP-SMX provides coverage of P multocida but lacks sufficient anaerobic coverage. Doxycycline and ciprofloxacin provide coverage of P multocida, but they too lack sufficient anaerobic coverage. (B) With a penicillin allergy the cross reactivity is about 10%. While we do not know the extent of the penicillin allergy there is no compelling reason to use a drug with a 10% risk unless there would be significant harm by using the recommended substitute regimen.
During an elective sigmoid resection for nonobstructing colon cancer, there is local leakage of liquid stool from the enterotomies prior to creation of the anastomosis. Which of the following describes how to classify this case for infection control?
Contaminated (class III)
There is gross spillage of enteric content in this case; therefore, it is a contaminated case. If there was no gross spillage, then it would be a clean contaminated case.
A 35-year-old carpenter who is right-hand dominant presents to the emergency department with an infection along the paronychial fold of his right index finger. He reports that he has had this infection for 2 days. He initially went to urgent care and was given a short course of antibiotics, but the infection continues to worsen. Examination confirms a fluctuant, tender mass just proximal to the nail. What is the proper treatment for this patient?
Incision and drainage with lifting of the nail bed
This patient has a paronychia. Incision and drainage of a paronychia requires lifting up the nail bed to evacuate the purulence. Antibiotic therapy would be an adjunct to treatment but is not the proper first-line treatment. Intravenous antibiotics would be used in a patient with systemic symptoms and septic arthritis. Incision and drainage of the fingertip pulp would be performed to treat a felon, not a paronychia.
An otherwise healthy 25-year-old healthy woman sustained a cat bite to the palm of her right hand. The next day, she presents to the ED for further management. Examination reveals a deep puncture wound with mild surrounding erythema but no purulence. There is no swelling along tendon sheaths or pain with passive finger extension. What is the most appropriate course of action?
Wound care and amoxicillin-clavulanate for 5 days
Animal bites are a common presenting complaint, and cat bites account for 5% to 10% of these bites. Cat bites are generally considered grossly contaminated and compared to other animal bites can be deeper. They are typically polybacterial, with Pasteurella multocida being a common bacterium. This can be a fast-progressing infection with signs of infection in the first 24 hours. Wounds should be copiously irrigated with saline.
Preemptive antibiotics for 3 to 5 days are recommended for (1) immunocompromised patients, (2) puncture wounds, (3) cases of delayed presentation, (4) hand, face, and foot bites, and (5) wounds that undergo primary closure. Primary closure is avoided, unless the bite affects cosmetically important areas such as the face, to reduce the risk of infection. Generally, surgical debridement is unnecessary for wounds without significant tissue damage or necrosis. The need for rabies prophylaxis must also be considered. This patient does not seem to have signs of deeper tendon sheath infection (flexor tenosynovitis). If these signs were present, then admission with intravenous antibiotics or surgical debridement would be needed.
A 40-year-old man is in the ED reporting severe pain and swelling of the right calf 4 days after sustaining a small laceration while doing yard work. On examination, there is cellulitis, severe tenderness, and warmth to the lower leg. He is febrile to 39.1 °C and tachycardic to 115 beats/min, with normal BP. A review of laboratory values demonstrates a WBC count of 13,000/μL, a C-reactive protein level of 160 mg/L, a creatinine level of 1.5 mg/dL, a serum bicarbonate level of 12 mEq/L, and a platelet count of 337 ×103/µL. When the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is calculated, what finding would contribute to this patient’s score?
C-reactive protein level of 160 mg/L
A C-reactive protein of 160 mg/L would contribute to this patient’s score because a value greater than 150 adds 4 points to the LRINEC Score. The LRINEC score is a tool that can be used to raise suspicion for a necrotizing soft tissue infection (NSTI). The score uses the following components: C-reactive protein, WBC count, hemoglobin, sodium, creatinine, and glucose. A score greater than 6 indicates suspicion for NSTI, and a score of greater than 8 is highly suspicious for NSTI. A WBC count greater than 15,000/μL is required to score a point on the LRINEC score. A patient’s platelet count, tachycardia, or serum bicarbonate level are not used to calculate the LRINEC score.
A 42-year-old homeless man with erythema and swelling of his ankles presents for the fourth emergency room visit to seek treatment for this condition. He has no known medical conditions besides hypertension, for which he is prescribed a beta-blocker, and he is very thin. His physical examination is unremarkable except for fissuring of his interdigital toe spaces and the aforementioned ankle cellulitis. What is the most likely etiology of his recurrent cellulitis?
Toe fissuring
Fissuring or maceration of the interdigital toe spaces as well as tinea pedis predispose a patient to recurrent cellulitis. Obesity is a risk factor for recurrence, not low body weight. Neither age nor beta-blocker use are related to recurrent cellulitis. Hypertension is not a risk factor for recurrence, but edema from impaired lymphatic drainage and venous insufficiency is.
You are evaluating a 40-year-old man with type 2 diabetes and obesity for an upper thigh skin infection. Which sign if exhibited by this patient would be concerning for a late physical examination finding of necrotizing fasciitis?
Crepitus
Severe pain is an early finding in necrotizing fasciitis. There may be few skin clues in the beginning of the disease process. Crepitus, bullae, and skin necrosis are findings that occur as the disease progresses.
