Erysipelas in a 60-Year-Old Man

A 60-year-old man presented with redness, swelling, and pain on his right lower leg of 3 day's duration. He recalled being scratched by underbrush while hiking in the woods a few days earlier; the patient denied other recent trauma or insect bites.

Vital signs were normal. White blood cell count was 15,000/µL, with 80% segmented neutrophils and 20% lymphocytes. There was no significant medical history; other than the leg rash, the physical examination was unremarkable. Erysipelas, or St Anthony's fire, was diagnosed. Some patients with this condition experience prodromal symptoms of malaise, chills, and fever, which were absent here.

Dr Sunita Puri of Decatur, Ala, writes that this dermal infection is most often caused by group A β-hemolytic streptococci and typically affects children and adults older than 40. The organism is difficult to culture from a lesion; thus, the diagnosis is based on the clinical presentation.

A break in the skin can provide a portal for the culprit organism; however, hematogenous seeding may also occur. The infection progresses along the superficial lymphatics and is seen most often on the face and extremities. After a 2- to 5-day incubation, tender or painful, hot lesions develop; these areas are shiny, erythematous, edematous, and sharply demarcated. The periphery appears to be irregular because of the characteristic distinct advancing edge of the inflammatory process. Red lymphatic streaks may advance toward the regional lymph nodes. The condition can recur and may cause chronic lymphedema.

Treatment includes bed rest and elevation of the affected extremity to reduce swelling and pain. Wet dressings may be soothing. Treat mild cases with oral or intramuscular penicillin; improvement usually occurs within 24 to 48 hours. Patients who have more severe disease may require in-hospital treatment with parenteral antibiotics. At least 10 days of adequate blood and tissue levels of penicillin are needed to kill streptococci. Erythromycin, clindamycin, a cephalosporin, or vancomycin may be used for patients who are allergic to penicillin.

This patient recovered after he was given an intramuscular dose of a third-generation cephalosporin, followed by oral therapy.