Comparison of the association with eczema herpeticum in the two predominant genotypes of herpes simplex virus type 1.

Eczema herpeticum, sometimes called Kaposi's varicelliform eruption, is usually caused by a disseminated herpes simplex virus infection in a patient whose underlying skin disease in atopic dermatitis. Herpes simplex virus type 1 (HSV-1), a widespread infectious agent in human populations, is the etiologic agent of eczema herpeticum. Analyses of restriction fragment length polymorphism (RFLP) of HSV-1 strains isolated in Japan, using restriction endonucleases, revealed the presence of two predominant genotypes of F1 and F35. The number of HSV-1 strains of F1 genotype was over twice that of the F35 genotype, and the nucleotide change between F1 and F35 was estimated to be 1.5%. The question of whether the genomic difference between two predominant genotypes could influence clinical manifestations remained to be addressed. On the basis of RFLP, we determined genotypes of HSV-1 strains isolated from the patients in Japan, including those with eczema herpeticum. Two of four HSV-1 strains of F35 genotype were from patients with eczema herpeticum, whereas none of 12 HSV-1 strains of F1 genotype was from those with eczema herpeticum. Thus, the F35 genotype seemed to be associated more frequently with eczema herpeticum than the F1 genotype.