The treatment of viral infections and nonmelanoma skin cancers.

Immunomodulatory therapy, which functions to upregulate immune response, may be directed against a variety of disease states, including viral infections and skin malignancies. Examples of immune response modifiers include injectable interferon (IFN) and topical imiquimod. Topical imiquimod has been studied for a variety of different disorders including human papillomavirus infection, molluscum contagiosum, actinic keratosis (AK), squamous cell carcinoma (SCC) in situ, superficial basal cell carcinoma (sBCC), nodular basal cell carcinoma (nBCC), and lentigo maligna. Case reports also have demonstrated use for select cases of extramammary Paget disease. This article focuses on therapies designed to augment immune response to treat viral infections and nonmelanoma skin cancers and reviews clinical applications, efficacy, recommended treatment regimens, monitoring of response, and avoidance of pitfalls associated with the use of topical imiquimod.