dermatoscopes

Dermatoscopes are handheld or mounted optical devices used in dermatology to inspect skin lesions with magnified, illuminated views of subsurface structures. They improve visualization beyond what the unaided eye can provide and aid in distinguishing benign from suspicious pigmented lesions and other skin conditions.

Most devices provide either non-polarized light with direct skin contact or polarized light with non-contact illumination. Non-polarized dermoscopy uses a liquid interface such as oil to reduce surface reflection; polarized dermoscopy uses cross-polarized light to minimize glare and often allows imaging without contact. Hybrid units offer both modes. Digital dermoscopy, including videodermoscopy and smartphone-based systems, captures high-resolution images for storage, comparison over time, and computer-assisted analysis.

Under dermoscopy, clinicians assess features such as pigment networks, dots and globules, streaks, regression structures, and vascular patterns. Interpreting these images often follows pattern-analysis schemes or risk calculators, such as the ABCD rule, the seven-point checklist, or other algorithms. Dermoscopy is routinely used for pigmented lesions and is increasingly applied to nonpigmented conditions such as basal cell carcinoma, seborrheic keratoses, and inflammatory dermatoses.

Procedure and maintenance: the examiner may apply a contact fluid or gel for some modes; after examination, devices and accessories are cleaned to prevent contamination. Digital storage enables longitudinal monitoring and remote consulting. Limitations include the need for training, interobserver variability, and the fact that dermoscopic findings are adjuncts to histopathology rather than definitive diagnoses.

History and scope: modern dermoscopy developed from earlier skin visualization tools, with major advances in polarized and digital systems occurring in the late 20th and early 21st centuries.