A 54-year-old woman comes to the office due to a slow-growing, painless mass in the right submandibular region. The patient had a right molar extraction for severe tooth decay 2 months ago and soon thereafter developed swelling of the right jaw. There was no pain or fever so she did not seek medical attention. The swelling slowly worsened and 3 days ago began draining a thick yellow discharge. The patient has a history of poorly controlled type 2 diabetes mellitus. Temperature is 37.2 C (99 F), blood pressure is 134/78 mm Hg, pulse is 88/min, and respirations are 18/min. Physical examination shows a 4x4 cm, firm, nontender, indurated mass below the angle of the right mandible with erythematous overlying skin. Palpation expresses serosanguineous fluid with small yellow granules through a small defect in the center of the lesion. There is no crepitus. Anaerobic culture of the needle aspirate grows filamentous gram-positive rods with rudimentary branching. Which of the following is the best initial treatment for this patient?

Question

A 54-year-old woman comes to the office due to a slow-growing, painless mass in the right submandibular region.  The patient had a right molar extraction for severe tooth decay 2 months ago and soon thereafter developed swelling of the right jaw.  There was no pain or fever so she did not seek medical attention.  The swelling slowly worsened and 3 days ago began draining a thick yellow discharge.  The patient has a history of poorly controlled type 2 diabetes mellitus.  Temperature is 37.2 C (99 F), blood pressure is 134/78 mm Hg, pulse is 88/min, and respirations are 18/min.  Physical examination shows a 4x4 cm, firm, nontender, indurated mass below the angle of the right mandible with erythematous overlying skin.  Palpation expresses serosanguineous fluid with small yellow granules through a small defect in the center of the lesion.  There is no crepitus.  Anaerobic culture of the needle aspirate grows filamentous gram-positive rods with rudimentary branching.  Which of the following is the best initial treatment for this patient?

Quizplus · Accepted Answer

11ec25c8_d43c_bd96_bc81_2100bc22ca8e_MD0003_00 Actinomyces is an anaerobic bacterium of the oral cavity that may cause invasive disease in patients with dental infections or trauma (eg, tooth extraction). Risk of infection is increased in those with poorly functioning immunity due to underlying immunosuppression, diabetes mellitus, or malnutrition. Infection occurs by direct extension from the oral cavity and is oblivious to tissue planes. Patients typically develop a chronic, slow-growing, nontender, indurated mass that eventually forms multiple sinus tracts to the skin. A pathognomonic feature is the presence of purulent discharge with "sulfur granules" (discrete yellow granules that resemble sulfur but do not contain it). Lymphadenopathy and fever are atypical. The mandible is the most common site of infection (>50%), but other nearby tissues (eg, cheek, chin) may be affected. Fine needle aspiration with culture is usually required to establish a diagnosis (cultures often take >14 days). High-dose oral penicillin is the first-line treatment for mild cases (no fistulas); more severe cases require intravenous penicillin and (often) concomitant surgery. (Choices A and C) Amphotericin B and fluconazole are common antifungal agents. This patient has a slowly enlarging, nonpainful jaw mass with sulfur granules after a dental procedure, strongly suggesting the bacterium Actinomyces (requiring an antibacterial agent, not an antifungal). (Choice B) Azithromycin is a macrolide antibiotic often used for respiratory infections (eg, community-acquired pneumonia, bronchitis) but is not commonly used for Actinomyces. (Choice D) Tuberculosis (TB) is treated with isoniazid, rifampicin, pyrazinamide, and ethambutol. TB lymphadenitis usually presents with chronic, nontender lymphadenopathy. Draining sinus tracts are uncommon. TB resembles Actinomyces on Gram stain, but TB is usually acid-fast (unlike Actinomyces). (Choice E) Although metronidazole is frequently used in the treatment of anaerobic (and parasitic) infections, it does not have efficacy against Actinomyces. (Choice G) Nocardia may be treated with trimethoprim-sulfamethoxazole and occasionally causes chronic, nonpainful subcutaneous lesions with draining sinus tracts. Skin inoculation usually occurs during gardening or farming, and infections typically arise on the feet, legs, or back. This patient with a submandibular lesion after a dental procedure is more likely to have Actinomyces. Educational objective: Actinomyces is part of the normal oral flora but may cause an invasive infection in patients who have dental infections or trauma (especially in those with weakened immunity). Symptoms include a chronic, slow-growing, nontender mass at or near the mandible. Multiple sinus tracts to the skin may drain purulent fluid with sulfur granules (discrete, yellow granules). Penicillin is the preferred therapy; surgery is sometimes required for severe cases. References: Actinomyces: a great pretender. Case reports of unusual presentations and a review of the literature. (http://www.ncbi.nlm.nih.gov/pubmed/18164641) Cervicofacial actinomycosis and mandibular osteomyelitis. (http://www.ncbi.nlm.nih.gov/pubmed/17561082)

A 54-Year-Old Woman Comes to the Office Due to a Slow-Growing