Dermoscopy in family medicine: A primer

What the research says

Dermoscopy improves sensitivity for detecting melanoma over the naked eye alone; it also allows for the detection of melanoma at earlier stages, which improves prognosis.⁶

A meta-analysis of dermoscopy use in clinical settings showed that, following training, dermoscopy increases the average sensitivity of melanoma diagnosis from 71% to more than 90% without a significant decrease in specificity.⁷ In a study of 74 primary care physicians, there was an improvement in both clinical and dermoscopic diagnosis of melanoma among those who received training in dermoscopy, compared with a control group.⁸ Another study found that primary care physicians can reduce their baseline benign-to-melanoma ratio (the number of suspicious benign lesions biopsied to find 1 melanoma) from 9.5:1 with naked eye examination to 3.5:1 with dermoscopy.⁹

The exam begins by choosing 1 of 3 modes of dermoscopy

Dermatoscopes can have a polarized or nonpolarized light source. Some dermatoscopes combine both types of light (hybrid dermatoscopes; see “Choosing a dermatoscope—and making the most of it.”)

There are 3 modes of dermoscopy:

1. nonpolarized contact dermoscopy
2. polarized contact dermoscopy
3. polarized non-contact dermoscopy.

Dermatoscopes with nonpolarized light require direct skin contact and a liquid interface (eg, alcohol, gel, mineral oil) between the scope’s glass plate and the skin for the visualization of subsurface structures. In contrast, dermatoscopes with polarized light do not require direct skin contact or a liquid interface; however, contacting the skin and using a liquid interface will provide a sharper image.

Continue to: Two major algorithms guide dermoscopic analysis