What is the most appropriate antibiotic therapy for a 44-year-old man with paronychia (infection of the nail fold) of the left long finger, complicated by poorly controlled type 2 diabetes mellitus and obesity, presenting with signs of cellulitis (erythema and purulent discharge)?

From the Guidelines

The most appropriate antibiotic therapy for this patient is vancomycin or another antimicrobial effective against both MRSA and streptococci, given the patient's complicated paronychia with signs of cellulitis and poorly controlled type 2 diabetes mellitus, which increases the risk of severe infection. This patient has paronychia (infection of the nail fold) that has progressed to cellulitis, as evidenced by the erythema and purulent discharge. Given the patient's poorly controlled diabetes, which increases susceptibility to infection and impairs healing, prompt and appropriate antibiotic therapy is essential. The patient's obesity and poorly controlled diabetes also classify them as a severely compromised patient, which may require broad-spectrum antimicrobial coverage 1.

Key Considerations

• The patient's infection is complicated by systemic signs of infection (cellulitis), which necessitates systemic antibiotics that cover streptococci and possibly MRSA 1.
• The patient's poorly controlled diabetes and obesity increase the risk of severe infection and complications, making broad-spectrum antimicrobial coverage a consideration 1.
• Vancomycin or another antimicrobial effective against both MRSA and streptococci is recommended for patients with severe nonpurulent infections or those who are severely compromised 1.

Treatment Recommendations

• Vancomycin or another antimicrobial effective against both MRSA and streptococci should be considered as the initial antibiotic therapy, given the patient's high risk of severe infection and complications.
• The recommended duration of antimicrobial therapy is 5 days, but treatment should be extended if the infection has not improved within this time period 1.
• In addition to antibiotic therapy, the patient should be advised to elevate the affected area, keep it clean and dry, and monitor blood glucose levels closely as infection can worsen glycemic control.
• If there is significant pus collection, incision and drainage may also be necessary alongside antibiotic therapy.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Adults The usual adult dose is one Amoxicillin and Clavulanate Potassium Tablet, USP (amoxicillin, 500 mg, as the trihydrate and clavulanic acid, 125 mg, as clavulanate potassium) every 12 hours or one Amoxicillin and Clavulanate Potassium Tablet 250 mg/125 mg every 8 hours For more severe infections and infections of the respiratory tract, the dose should be one Amoxicillin and Clavulanate Potassium Tablet, USP (amoxicillin, 875 mg, as the trihydrate and clavulanic acid, 125 mg, as clavulanate potassium) every 12 hours or one Amoxicillin and Clavulanate Potassium Tablet, USP (amoxicillin, 500 mg, as the trihydrate and clavulanic acid, 125 mg, as clavulanate potassium) every 8 hours.

The most appropriate antibiotic therapy for a 44-year-old man with paronychia complicated by poorly controlled type 2 diabetes mellitus and obesity, presenting with signs of cellulitis, is Ampicillin-Clavulanate (500 mg/125 mg every 8 hours or 875 mg/125 mg every 12 hours), considering the infection is severe and the patient has underlying health conditions that may affect the severity of the infection 2.

• The patient's renal function should be assessed before initiating therapy, as dose adjustments may be necessary in cases of severe renal impairment.
• The patient should be advised to take the medication at the start of a meal to enhance absorption and minimize gastrointestinal intolerance.

From the Research

Antibiotic Therapy for Paronychia with Cellulitis in a Patient with Type 2 Diabetes Mellitus and Obesity

• The patient's condition is complicated by poorly controlled type 2 diabetes mellitus and obesity, which can affect the choice of antibiotic therapy 3.
• The presence of cellulitis, erythema, and purulent discharge suggests a bacterial infection, likely caused by Staphylococcus aureus, which is a common pathogen in skin and soft tissue infections 4, 3.
• The choice of antibiotic therapy should be based on the severity of the disease, potential etiologic agents, and the patient's underlying medical conditions 3.
• Amoxicillin/clavulanate may be effective against methicillin-susceptible S. aureus (MSSA) infections, but its use against methicillin-resistant S. aureus (MRSA) is still experimental and not currently advocated 5.
• Other antibiotics such as flucloxacillin, dicloxacillin, and first-generation cephalosporins may be effective against MSSA infections, but may not be suitable for patients with penicillin hypersensitivity 4.
• For MRSA infections, vancomycin or teicoplanin may be used, but the emergence of resistance is a concern 4, 6.
• Moxifloxacin, a broad-spectrum fluoroquinolone, may be an effective alternative for treating diabetic foot infections, including those caused by MRSA 7.
• The use of combination antibiotic therapy, such as vancomycin plus daptomycin or linezolid, may be considered for serious MRSA infections, but the evidence is limited and more studies are needed 6.