Increased Risk for MRSA Skin and Soft Tissue Infections Among HIV-Infected Persons

Nancy F. Crum-Cianflone, MD, MPH

Disclosures

January 15, 2010

Case Description: Methicillin-Resistant Staphylococcus aureus Infection in an HIV-Infected Man

History

The patient is a 32-year-old man with HIV diagnosed in 1995 after presenting with cryptococcal meningitis. The patient recovered from the meningitis and was prescribed secondary prophylaxis with fluconazole. Despite the initiation of antiretroviral therapy, the recovery of his CD4+ count was suboptimal due to poor medication compliance, and additional opportunistic infections subsequently developed, including Mycobacterium avium-complex (MAC) as well as recurrent skin furuncles caused by methicillin-resistant Staphylococcus aureus (MRSA). His allergies included severe reactions to intravenous vancomycin and trimethoprim-sulfamethoxazole (TMP-SMX).

Presentation

In early 2008, a pustule developed on the patient's right lower extremity. Over the course of the next few days, this evolved into cellulitis followed by progressive edema of his calf area including proximal extension to his thigh. The patient presented with 10/10 pain in his lower extremity and an inability to ambulate. Three weeks before his presentation, he had self-discontinued all medications including all antiretroviral and prophylactic medications against opportunistic infections.

Evaluation

Physical examination revealed a blood pressure of 104/73 mm Hg, pulse of 137 beats/minute, and indurated areas of both the medial upper thigh (4 x 10 cm) and calf area (6 x 20 cm). Both areas were edematous, erythematous, and expressed serosanguineous discharge. There was pain out of proportion on the examination (mild touching of the area resulted in intense pain).

Laboratory evaluation revealed a white blood cell count of 5400 cells/mcL, hemoglobin 8.8 mg/dL, and platelet count 76,000. His most recent CD4+ count was 76 cells/mcL with a HIV RNA level of > 100,000 copies/mL (> 5 log10 units). He was immediately admitted given concerns of a necrotizing soft-tissue infection and possible fasciitis. Empiric therapy with daptomycin, clindamycin, and imipenem was initiated.

An emergent magnetic resonance image of the lower extremity showed diffuse circumferential edema of the lower leg and thigh, with fluid tracking between the layers of the musculature with the formation of multiple abscesses (Figure).

Figure. Magnetic resonance image of the lower extremity shows a necrotizing soft-tissue infection with multiple abscesses involving the medial upper thigh (a) and calf (b) areas.

Treatment

Surgical debridement of the thigh and calf revealed necrotic soft tissue and purulent fluid collections; extensive incisions were used to adequately drain the involved tissues, and wound vacuum-assisted closure (VAC) devices were put into place. The fascia was intact and without evidence of necrotizing fasciitis. Septic shock developed on day 1 of hospitalization, and the patient was treated with activated protein C.

Culture specimens of the wounds grew MRSA sensitive to vancomycin, daptomycin, linezolid, and TMP-SMX, but resistant to clindamycin and tetracyclines. A nares culture result was also positive for MRSA, but all blood culture specimens were sterile. The patient underwent a course of intravenous daptomycin, followed by oral linezolid. The patient eventually recovered after a prolonged convalescence due to slow wound closure. He underwent desensitization to sulfa medications and was placed on TMP-SMX for both Pneumocystis jiroveci/carinii pneumonia (PCP) and MRSA prophylaxis. Antiretroviral medications were re-initiated.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....