Denouement and Discussion
The lesions of varicella gangrenosum usually occur between the fourth and seventh days following the onset of chickenpox. The rash is initially erythematous, turns blue within 24 to 48 hours, and then eventually becomes necrotic. It is postulated that the varicella virus disrupts the integrity of the epidermis, allowing the virus to easily grow. The most common organism found in varicella gangrenosum is Streptococcus pyogenes, but other organisms, especially Staphylococcus aureus, have also been cultured from the necrotic lesions and/or blood-stream. Varicella gangrenosum is reported to occur in approximately 0.10% of patients who develop chickenpox.
Surgical excision of the necrotic tissue is essential, and appropriate antibiotic therapy based on culture results should be started promptly. Early empiric therapy should be effective against both S pyogenes and S aureus.
Congeni BL, Ulbrich M, Feingold M. Picture of the Month. Am J Dis Child. 1985;139(11):1151-1152. doi:10.1001/archpedi.1985.02140130089037