Eczema herpeticum has emerged as the most common form of Kaposi varicelliform eruption since the discontinuation of routine smallpox vaccination. It can be a serious complication of infantile eczema, with a death rate as high as 9%.1 Successful treatment with systemic administration of cytarabine has been reported, but the true value of this drug remains to be determined.2 Furthermore, cytarabine is not without toxic effects—notably bone marrow depression— after being administered systemically.
Methylene blue, a phenothiazine derivative, has been shown to be viricidally active toward herpesvirus hominis in the presence of light exposure, both in vitro3 and in vivo.4 The dye enters living cells, but transiently, thus inactivating both extracellular and intracellular viruses with minimal damage to the cells. Recently, a controlled study indicated methylene blue's therapeutic effectiveness in eczema herpeticum.5 Local application of 0.1% methylene blue solution to half of the diseased area followed
Chang T. Methylene Blue for Eczema Herpeticum. JAMA. 1975;233(9):987. doi:10.1001/jama.1975.03260090053028