Erysipelas

Erysipelas is an acute bacterial infection of the dermis and hypodermis that is associated with clinical inflammation. It is a specific clinical type of cellulitis and, as such, it should be studied as a specific entity. Erysipelas is generally caused by group A streptococci; it is highly probable that streptococcal toxins also play a role, which could, in part, help explain the clinical inflammation.

Erysipelas of the leg is the main clinical type encountered. The face, arm, and upper thigh are the other most common sites for the occurrence of erysipelas. After a sudden onset, areas of erythema and edema characteristically enlarge with well-defined margins. Athlete’s foot is the most common portal of entry for the disease. Erysipelas is generally associated with high fever, and adenopathy and lymphangitis are sometimes present.

At the time of diagnosis, it is important to look for clinical markers of severity (local signs and symptoms, general signs and symptoms, co-morbidity, social context) which would necessitate hospitalization.

There are many differential diagnoses, particularly in the case of atypical dermo-hypodermitis. Some bacterial infections may have specific clinical aspects or may lead to a diagnosis of cellulitis. Necrotizing cellulitis or fasciitis are life-threatening diseases and a rapid diagnosis is important. Other noninfectious types of cellulitis have been reported in many diseases, both localized or generalized.

The biology of typical erysipelas is of little value in diagnosis and a laboratory workup is usually not required. There are few local complications associated with erysipelas; abscess can occur in some patients and septicemia is rare. Recurrence is the more distressing complication.

Treatment of patients with erysipelas has been evaluated in a small number of studies. In most of them, erysipelas has been included in therapeutic studies of ‘severe cutaneous infections’. This is not justified as in fact erysipelas is usually sensitive to penicillin G. Amoxicillin and macrolides are also effective. However, comparative, cost-analysis studies need to be performed to determine the best therapeutic option. Bed rest with the leg elevated is also important. Anticoagulants are indicated in patients at risk of venous thromboembolism. The portal of entry will also require treatment. Long-term antibacterial therapy is required for patients with recurrence.