Viral and Rickettsial Diseases

Viral infection is a major source of cutaneous disease, and skin lesions are frequently biopsied. Viropathic changes help to identify various types of viruses, while in some cases secondary changes, such as keratinocyte dysplasia, identify the offending virus. Viral infections can be limited to the skin, but systemic infection may also give rise to cutaneous manifestations. Rickettsial infections are far less commonly biopsied. Skin involvement is generally associated with systemic disease that is often quite serious.