A 36-year-old woman comes to the office due to a right lower extremity rash. The patient developed a large abrasion over her right ankle after falling off her mountain bike 3 days ago. Yesterday, she noticed progressive, painful red streaks near the wound. She has no chronic medical conditions and takes no medications. Temperature is 38.2 C (100.8 F), blood pressure is 126/78 mm Hg, and pulse is 92/min. Examination reveals a 4-cm abrasion just superior to the right lateral malleolus; no purulence or induration is present, but there are several tender, erythematous streaks extending proximally from the wound toward the knee. Tender, enlarged lymph nodes are also present in the right popliteal fossa. Which of the following is the most appropriate treatment for this patient?
Lymphangitis | |
Epidemiology |
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Manifestations |
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Treatment |
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MSSA = methicillin-sensitive Staphylococcus aureus. | |
This patient had a skin abrasion and subsequently developed tender, erythematous streaks extending towards her knee and regional lymphadenopathy, raising strong suspicion for acute infectious lymphangitis. Most cases develop in the setting of cutaneous wound, which creates a portal for skin pathogens to enter the deep dermis and invade lymphatic channels. Patients generally have tender, erythematous streaks extending from the wound toward the draining lymph nodes; regional tender lymphadenopathy (lymphadenitis) and systemic symptoms (eg, fever) are often present.
The leading causes of lymphangitis are Streptococcus pyogenes and methicillin-sensitive Staphylococcus aureus (MSSA); therefore, empiric treatment with cephalexin is generally curative.
(Choice A) Azithromycin is often used for upper respiratory infection due to excellent activity against a number of gram-positive upper respiratory pathogens, including S pyogenes. However, it is not regularly used for skin and soft tissue infection due to limited activity against MSSA.
(Choice C) Ciprofloxacin is primarily used for gram-negative bacterial infections, particularly those that arise below the level of the diaphragm (eg, urinary tract, gastrointestinal). It has limited activity against gram-positive bacteria and is not commonly employed for skin and soft tissue infections.
(Choice D) Griseofulvin is an antifungal agent that is primarily used to treat cutaneous fungal infections (eg, ringworm). This patient with tender erythematous streaks and regional lymphadenitis following a cutaneous injury is far more likely to have a bacterial infection.
(Choice E) Itraconazole is an antifungal agent that is often used to treat sporotrichosis, the leading cause of nodular lymphangitis. In contrast to acute infectious lymphangitis, nodular lymphangitis is marked by the formation of nodular swellings along the proximal lymphatic channel over the course of weeks (not days). Gardeners are classically affected.
(Choice F) Although penicillin V has activity against S pyogenes, it is not typically employed for skin and soft tissue infections because many strains of MSSA are resistant.
Educational objective:
Acute infectious lymphangitis is marked by the formation of proximal, tender, erythematous streaks at the site of skin wound with regional lymphadenopathy and systemic symptoms (eg, fever). Most cases are caused by Streptococcus pyogenes or methicillin-sensitive Staphylococcus aureus; therefore, treatment with cephalexin is generally curative.