Lack of host cellular immune response in eruptive molluscum contagiosum.

A lack of cellular immunity on the part of the host has been incriminated as the cause of the persistence of the cutaneous lesions of molluscum contagiosum. We present a patient in the eruptive phase of the disease, confirming the absence of T-lymphocyte and natural killer cell subsets in the base of these typical lesions, using a panel of monoclonal antibodies. We also report the observation of lipid material ultrastructurally (confirmed by osmium staining on fresh-frozen tissue), as well as cross-reactivity immunocytochemically of the antigens on these molluscum bodies with antigens normally present on macrophages, as defined by DAKO-macrophage monoclonal antibodies. We have considered the possible role of these findings in the lack of host cellular responsiveness in the eruptive phase of the disease.