Question 1 of 4
(demo test)
Product Demo for MohsQBank
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A patient presents to you for micrographic dermatologic surgery of a large 3.0 cm squamous cell carcinoma (SCC) of the right lower extremity. On clinical examination, the plaque is quite inflammatory. During preoperative questioning, you determine that the patient has well-controlled rheumatoid arthritis and is currently taking methotrexate and low-dose prednisone. His other past medical history is significant for recent joint replacement 6 months ago with a postoperative joint infection requiring repeat surgery, diabetes mellitus type II, and chronic renal failure (grade III). Which antibiotic regimen is most appropriate?
Diagnosis & Management of Keratinocyte and other Non-Melanoma Skin Cancers
Prophylaxis
U
B
2 grams of cephalexin 30-60 minutes prior to surgery is the correct answer in this clinical scenario in order to prevent prosthetic joint infection (PJI).
Risk factors for prosthetic joint infection that require antibiotic prophylaxis if dermatologic surgery involves infected skin or incision of oral mucosa
- Previous joint infection
- All patients within two years of joint replacement
- Patients with inflammatory arthropathies
- Drug or radiation induced immunosuppression
- Comorbidities including type 1 diabetes mellitus, HIV infection, malnutrition, concurrent malignancy, hemophilia
2 grams of amoxicillin 30-60 min prior to surgery would be the correct choice for incision of mucosal skin in a patient requiring preoperative antibiotics for prevention of PJI.
If penicillin allergic, the guidelines are the same for keratinized and mucosal skin: 600 mg clindamycin, 500 mg azithromycin or 500 mg clarithromycin 30-60 min prior to surgery for prevention of dermatologic surgical site infections (DSSI) and infective endocarditis (IE). For prevention of prosthetic joint infections (PJI), only 600 mg of clindamycin is recommended one hour prior to surgery (J Am Dent Assoc 2003).
Postoperative antibiotics are used on a case-by-case basis in dermatologic surgery. However, when antibiotics are given to prevent dermatologic surgery site infections, infective endocarditis, and prosthetic joint infections, the preoperative approach is recommended (Wright et al. JAAD 2008).
The patient has a history of a previous joint infection, recent joint replacement 6 months prior, and has an inflammatory arthropathy going into a dermatologic surgery of squamous cell carcinoma of the lower leg that has substantial inflammation. Infected skin is a possibility and the lower leg is a high risk site for infection. Thus, a preoperative antibiotic is needed.
The history of renal failure does not typically affect the preoperative loading dose of an antibiotic (or any other medication for that matter), but it would affect the dosing schedule if a postoperative antibiotic were to be given.
For further review: See the below outline:
Antibiotic prophylaxis in dermatologic surgery is recommended for the following patients (of note, the AHA recommends 30-60 minutes preoperative and the ADA-AAOS recommends 60 minutes preoperative): (Wright et al. J Am Acad Dermatol 2008)
Patients WITHOUT high-risk cardiac conditions or total joint replacements (prophylaxis still recommended based on increased risk of surgical site infection)
- Surgery on the lower extremity
- Surgery in the groin
- Wedge excisions of lip or ear
- Skin flaps on the nose
- Skin grafting
- Extensive inflammatory skin disease
The recommended prophylactic antibiotics for dermatologic surgical procedures in patients WITHOUT high-risk cardiac conditions or total joint replacements are as follows:
- Lesions on lower extremities and groin
- Cephalexin 2 grams PO x 1 or TMP-SMX DS 1 tablet PO
- If allergic to penicillin, TMP-SMX DS 1 tablet PO or Levofloxacin 500 mg PO x 1
- If unable to take PO and if allergic to penicillin, clindamycin and gentamycin 600mg/2mg/kg IV
- Wedge excision of lip or ear; flaps on nose; all grafts
- Cephalexin or dicloxacillin 2 grams PO x 1
- If allergic to penicillin, clindamycin 600 mg PO x 1 or azithromycin/clarithromycin 500 mg PO x 1
- If unable to take PO and if allergic to penicillin, clindamycin 600mg IM/IV
Patients WITH high-risk cardiac conditions:
- Prosthetic heart valve
- History of infectious endocarditis
- Unrepaired cyanotic congential heart defect
- Repaired congenital heart defect with prosthetic materials or devices first 6 months after procedure
- Repaired congenital heart defect with residual defects at site or adjacent to site of prosthetic patch or device
- Cardiac transplant recipient with cardiac valvulopathy
The recommended prophylactic antibiotics for dermatologic surgical procedures in patients WITH high-risk cardiac conditions and who are at risk of infective endocarditis are as follows:
- Non-oral high-risk surgical site (lower extremity, groin, wedge excisions of lip or ear, skin flaps on the nose, skin grafting, extensive inflammatory skin disease)
- Cephalexin or dicloxacillin 2 grams PO x 1
- If allergic to penicillin, clindamycin 600 mg PO x 1 or azithromycin/clarithromycin 500 mg PO x 1
- If unable to take PO, cefazolin/ceftriazone 1g IM/IV
- If unable to take PO and if allergic to penicillin, clindamycin 600 mg IM/IV
- Non-oral (skin infected and pathogen known)
- Antibiotic selected based on specific pathogen
- Oral (breach of oral mucosa)
- Amoxicillin 2g PO x 1
- If allergicto penicillin, clindamycin 600 mg PO x 1 or azithromycin/clarithromycin 500 mg PO x 1
- If unable to take PO, cefazolin/ceftriazone 1g IM/IV or Ampicillin 2 grams IM/IV
- If unable to take PO and if allergic to penicillin, clindamycin 600 mg IM/IV
Patients WITH total joint replacements:
- First 2 years after joint replacement
- Previous prosthetic joint infection
- Type I diabetes mellitus (DM)
- Immunosuppression or malignancy
- Malnourishment
- Inflammatory arthropathies (rheumatoid arthritis, systemic lupus erythematous)
- Hemophilia
- HIV infection
- Malignancy
The recommended prophylactic antibiotics for dermatologic surgical procedures in patients WITH total joint replacements and who are at risk of hematogenous total joint infection are as follows:
- Non-oral high-risk surgical site (lower extremity, groin, wedge excisions of lip or ear, skin flaps on the nose, skin grafting, extensive inflammatory skin disease)
- Cephalexin or dicloxacillin 2 grams PO x 1
- If allergic to penicillin, clindamycin 600 mg PO x 1 or azithromycin/clarithromycin 500 mg PO x 1
- If unable to take PO, cefazolin/ceftriazone 1gram IM/IV
- If unable to take PO and if allergic to penicillin, clindamycin 600mg IM/IV
- Non-oral (skin infected and pathogen known)
- Antibiotic selected based on specific pathogen
- Oral (breach of oral mucosa)
- Amoxicillin 2grams PO x 1
- If allergic to penicillin, clindamycin 600 mg PO x 1 or azithromycin/clarithromycin 500 mg PO x 1
- If unable to take PO, cefazolin/ceftriazone 1 gram IM/IV or Ampicillin 2 gram IM/IV
- If unable to take PO and if allergic to penicillin, clindamycin 600 mg IM/IV
Clinical Pearl: Cephalexin OR dicloxacillin 2 grams PO x 1 are the antibiotics of choice for prevention of prosthetic joint infections (PJI) when operating on a non-oral high-risk surgical site.
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