As far as the infrequently affected sites are concerned, one may observe erysipelas of the trunk following surgery, erysipelas of the abdomen in the neonate following infection of the umbilical stump, and erysipelas of the external genitalia as the result of an infected circumcision site. Other portals of entry include chronic leg ulcers, tinea pedis, insect bites, eczema, and venectomy for coronary artery bypass surgery. In the majority of erysipelas cases, group A beta-hemolytic streptococci are the responsible organisms with group G streptococci being the second most frequent causative organism. However, group B and C streptococci, Staphylococcus aureus, Streptococcus pneumoniae, Hemophilus influenzae, and Yersinia enterocolitica have all been reported as etiologic organisms. Patients may become bacteremic developing metastatic foci of infection.
Infants are at particular risk for systemic spread.
Complications such as sepsis, deep gangrene, abscess formation, or death due to systemic toxicity are more frequent in the immunocompromized patient. An intense treatment regimen is warranted in patients suffering from diabetes mellitus, cirrhosis, malignancies, and alcohol abuse. Cultures of tissue aspirate from the advancing border of the lesion and cultures of the nose and throat typically are positive for group A streptococci, as are blood cultures in septic patients. The laboratory evaluation usually shows an elevated white blood cell count with polymorphonuclear leukocytes and nonspecific signs of inflammation such as increased erythrocyte, sedimentation rate and elevated fibrinogen. The clinical picture of erysipelas is so characteristic that streptococcal infection can be presumed and antimicrobial treatment initiated.