Erysipelas 

Erysipelas is a superficial bacterial skin infection that characteristically extends into the cutaneous lymphatics. Erysipelas has been traced back to the Middle Ages, where it was referred to as St. Anthony's Fire, named after an Egyptian healer who was known for successfully treating the infection. Historically, erysipelas occurred on the face and was caused by Streptococcus pyogenes. However, a shift in the distribution and etiology of erysipelas has occurred, with most erysipelas infections now occurring on the legs and with non–group A streptococci sometimes being identified as the etiologic agents.

Bacterial inoculation into an area of skin trauma is the initial event in developing erysipelas. Thus, local factors, such as venous insufficiency, stasis ulcerations, inflammatory dermatoses, dermatophyte infections, insect bites, and surgical incisions, have been implicated as portals of entry. The source of the bacteria in facial erysipelas is often the host's nasopharynx, and a history of recent streptococcal pharyngitis has been reported in up to one third of cases. Other predisposing factors include diabetes, alcohol abuse,^[1] HIV infection, nephrotic syndrome, other immunocompromising conditions, and vagrant lifestyle.

Preexisting lymphedema is a clear-cut risk factor for erysipelas. Recurrent erysipelas complicating the lymphedema from breast cancer treatment is well documented.^{[2, 3]} Lymphoscintigraphy in patients with a first-time episode of lower extremity erysipelas has documented lymphatic impairment in both affected and nonaffected legs. Thus, subclinical lymphatic dysfunction is a risk factor for erysipelas.^[4]

In erysipelas, the infection rapidly invades and spreads through the lymphatic vessels. This can produce overlying skin "streaking" and regional lymph node swelling and tenderness. Immunity does not develop to the inciting organism.

Frequency

United States

Isolated cases are the rule with erysipelas, although epidemics have been reported. The incidence of erysipelas declined throughout the mid-20th century, possibly due to antibiotic development, improved sanitation, and decreased virulence.^[5] The change in distribution from the face to the lower extremities is most likely related to an aging population with risk factors such as lymphedema. Approximately 85% of cases of erysipelas occur on the legs rather than the face.

International

Erysipelas is somewhat more common in European countries. Isolated cases are still the rule, and distribution and etiology remain similar to that in the United States.

Mortality/Morbidity

The most common complaints during the acute infection include tenderness of the involved area, fever, chills, and swelling. Death as a direct result of erysipelas is exceedingly rare. Predisposed patients often develop local recurrence, and this can lead to disfiguring and disabling healing reactions, such as elephantiasis nostras verrucosa. This chronic warty, edematous condition is caused by lymphatic destruction from repeated infection.

Race

Erysipelas infections affect persons of all races.

Sex

Erysipelas has been reported to be more common in females, but occurring at an earlier age in males because of their more aggressive activities. Other studies indicate that predisposing factors, rather than gender, account for any male/female differences in incidence.

Age

Cases of erysipelas have been reported in all age groups, but it does appear that infants, young children, and elderly patients are the most commonly affected groups. The peak incidence has been reported to be in patients aged 60-80 years, especially in patients who are considered high-risk and immunocompromised or those with lymphatic drainage problems (eg, after mastectomy, pelvic surgery, bypass grafting).