Diagnosis: Lyme Disease
• The initial skin lesion of Lyme disease is a papule composed of a mixed inflammatory cell infiltrate, focal hemorrhage, and only rare spirochetes. Spirochetes are haphazardly distributed in the dermis, are mostly extracellular, and are often found around dermal blood vessels.
• B. burgdorferi, the causative agent of Lyme disease, is an elongated spirochete staining best with silver stains, such as Steiner, Dieterle, and Warthin-Starry.
• The Steiner silver stain contains an additional incubation step with amylase, which allows for clearer delineation of organisms compared with other silver stains.
• Immunohistochemical studies are another diagnostic alternative for tissue samples that yield high sensitivity and specificity.
