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Infectious Disease and Medical Microbiology > Skin, Soft Tissue Infection > Flashcards

Flashcards in Skin, Soft Tissue Infection Deck (56)
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What is the most common infectious agent in cat bites? Dog bites?

Cat: Pastuerella multicoda
Dog: Pasteurella canis


What percentage of cat bites become infected compared to dog bites?

80% vs 5%


What is empiric treatment for dog or cat bites?



What are the most common infectious organisms in a human bite? (7)

-Viridins strep 100%
-Bacteroides 82%
-Staph epidermidis 53%
-Corynebacterium 41%
-Staph aureus 29%
-Peptostreptococcus 26%
-Eikenella 15%


What are two vaccine-able disease that always need to be considered with animal bites?



What are the conditions when a bite would be treated for tetanus?

-Vaccine: minor wound and no vaccine in last 10 years or major wound and no vaccine in last 5 years
-Tetanus Ig: major wound and has not had at least 3 vaccine doses


What is the treatment plan if an animal bite might have passed on rabies?

-Rabies Ig around the wound
-Rabies vaccine at day 0, 3, 7 and 14


What organism causes Cat Scratch Disease?

Bartonella henselae


What is the typical and atypical presentations of Cat Scratch Disease?

Typical: Local lymphadenitis +/- cutaneous lesions several days after exposure that can last 1-3 weeks
Atypical (10%): liver, spleen, ocular, neurological or MSK involvement, fever of unknown origin


What tests are typically used to diagnose Cat Scratch Disease? What would you treat it with?

-Serology (IFA), blood culture, tissue PCR
-Treatment: Azithromycin


What presents as these two classic syndromes:
-triad of tenosynovitis, polyarthritis, dermatitis
-purulent arthritis

Disseminated Gonococcal Infection


What is not common in Disseminated Gonococcal infection?

Urethritis/Cervicitis (but swabs often +ve)


What treatment is used for disseminated gonococcal infection?

Ceftriaxone + Doxycycline x 7 days

(Don't forget to Tx partners!)


What is the most common cause of septic arthritis?

Hematological spread > trauma/bite > post-surgery > direct spread from osteomyelitis


What is the most common organism that causes septic arthritis?

Staph aureus


What is the treatment for septic arthritis?

-IV antibiotics based on Gram stain x 4 weeks making sure to cover Staph
-Joint aspiration in all cases, surgical drainage in hip or prosthetic infection


What is Ludwig's Angina?

Cellulitis of the submandibular/sublingual spaces


What does Ludwig's Angina almost always result from?

-Oral infection of 2nd or 3rd molars
-80% of patients report tooth pain or recent dental work


How do you manage Ludwig's Angina?

-Manage and protect airway (1/3 of cases require intubation)
-IV antibiotics based on organism
-Surgical evalualtion
-CT scan to evaluate abscess and extent of spread


What are the two most common causes of impetigo?

-S. aureus
-Group A strep


What are the two types of impetigo and their most obvious clinical feature?

Bullous (vesicles) and non-bullous (golden crust)


What are some risk factors for having a diabetic foot infection? (7)

-Previous amputation
-Wound extending to bone
-Peripheral vascular disease
-Ulcer duration >30days
-Loss of sensation
-History of recurrent ulcers
-Wound caused by trauma


Would you need to culture a minor infection if the patient has not received antibiotics within the last month?



If you are treating a foot infection in a patient that HAS received antibiotics in the past month, what modifications to antibiotic therapy must you make?

Cover gram negative rods


What is the presentation of a mild infection?

Local infection involving only the skin and subcutaneous tissue. If erythema is present, must be <2 cm around the wound.


What is the presentation of a moderate infection?

Local infection with erythema >2 cm or involving deeper structures than skin and subcutaneous tissues (eg: acbess, osteomyelitis, septic arthritis, faciitis) AND no systemic inflammatory response.


What is the presentation of a severe infection?

Local infection with signs of SIRS, as manifested by 2+ of the following:
-Temperature >38 Celsius or 90 bpm
-RR >20/min or PaCO2 12,000/mcL or 10% immature forms


What is empiric therapy for a severe infection?

Vancomycin and Pipercillin-Tazobactam/4th gen cephalosporin/carbapenem


Rank the most likely places to get cellulitis?

lower extremities > upper extremity > face


What organisms almost always cause cellulitis?

Staph or Strep