Review Question - QID 220793

This patient, who presents with slowly progressive erythema and pain of his lower extremity without concerning changes in the neurovascular exam, most likely has cellulitis.

Cellulitis is commonly characterized by inflammation of the skin and subcutaneous tissues, usually in response to an acute infection. A breach in the skin is often the initial inciting factor. Cellulitis presents as an acute and progressive onset of a red, warm, and edematous area of skin. The diagnosis is made clinically; however, ultrasound can show edema and cobblestoning. The treatment of cellulitis is an oral antibiotic that covers for staphylococcus and streptococcus, such as cephalexin.

Raff and Kroshinsky review the evidence regarding the diagnosis and treatment of cellulitis. They discuss how the treatment of uncomplicated cellulitis should be directed against Streptococcus and methicillin-sensitive S. aureus. They recommend consideration of resistant organisms for patients who fail to improve.

Figure/Illustration A is a clinical photograph demonstrating erythematous changes in the lower extremity (red circle). These findings are consistent with a diagnosis of cellulitis.

Incorrect Answers:
Answer 1: Atopic dermatitis is a pruritic rash that typically starts during childhood and occurs in the flexural surfaces of the elbow and knee. Patients would present with pruritus rather than pain. Treatment is with emollients.

Answer 3: Deep venous thrombosis presents with unilateral lower extremity swelling and pain. It can present with distal color changes in the foot due to changes in vascular perfusion. It would not present with painful surface erythema in the middle of the leg. Treatment is with anticoagulation.

Answer 4: Gas gangrene is caused by Clostridium perfringens and presents with rapidly progressive ascending infection of the extremity. Patients will present with large gaseous bullae. It is rapidly fatal if left untreated and would not have a slow progression. Treatment is with emergent surgical debridement and broad-spectrum antibiotics.

Answer 5: Necrotizing fasciitis is a rapidly progressive infection of the soft tissues that is fatal if left untreated. It progresses extremely rapidly and would not have a slow expansion over time. Treatment is with emergent surgical debridement and broad-spectrum antibiotics.

Bullet Summary:
Cellulitis presents with slowly progressive erythema and pain of the lower extremity without concerning changes in the neurovascular exam.