The VisualDx system (http://www.logicalimages.com/prodVDx.htm) is a JAVA-based decision-support program developed by Logical Images to be used in clinical care to develop differential diagnoses based upon morphologic finding- and patient finding-driven searching. It consists of several modules, many of which are very relevant to infectious diseases specialists, such as Fever & Rash; International Travel; Drug Eruptions; Smallpox Vaccination; Terrorism Recognition; Immunocompromised, HIV or AIDS; Female Genital Rashes & Growths; and Male Genital Rashes & Growths. Unlike books and atlases indexed by disease, with VisualDx, clinicians can enter patient descriptors and lesion morphologies, resulting in rapid assistance with differential diagnosis. VisualDx also increases clinician awareness of, knowledge about, and skills in the recognition of chemical warfare, bioterrorism, and radiation injuries.