Dermatoscopy (also known as dermoscopy or epiluminescence microscopy) is the examination of skin lesions with a dermatoscope, a magnifier (typically x10) with a light and a liquid medium between the instrument and the skin, thus illuminating the lesion without reflected light.

This instrument is helpful to dermatologists in distinguishing benign from malignant (cancerous) lesions, especially of aid in the diagnosis of malignant melanoma. It uses either cross-polarized or non-polarized light.

Only 20 to 25 per cent of dermatologists in the United States use dermatoscopy.^[1]

Contents 1 Advantages of Dermatoscopy 2 Application of Dermatoscopy 3 History 4 External links 5 References

[edit] Advantages of Dermatoscopy

With doctors who are experts in the specific field of dermoscopy, the diagnostic accuracy for melanoma is significantly better than for those dermatologists who do not have any specialized training in dermatoscopy.^[2] Thus, with specialists trained in dermoscopy, there is indeed a considerable improvement in the sensitivity or detection of malignant melanomas as well as specificity or percentages of non-melanomas correctly diagnosed as compared with the traditional clinical naked eye examination.

Studies conducted have revealed that the accuracy by dermatoscopy was increased up to 20% in the case of sensitivity and up to 10% in the case of specificity.^[3][4][5][6] It also goes to show that detection of undiagnosed melanomas by the naked eye method is greater compared to the detection of benign lesions. By using dermatoscopy the specificity is thereby increased reducing the frequency of unnecessary surgical excisions of benign lesions.^[7][8]

Dermatoscopy reduces the need for a biopsy. Compared to only naked eye examination in detection of melanoma conducted by dermatologists, naked eye examination coupled with dermatoscopy reduces the number of patients referred to for biopsy or excision.^[1]

[edit] Application of Dermatoscopy

1. The typical application of dermatoscopy is early detection of melanoma (see above)
2. Digital dermatoscopy (videodermatoscopy) is used for monitoring skin lesions suspicious of melanoma. Digital dermatoscopy images are stored and compared to images obtained during the patient's next visit. Suspicious changes in such a lesion are an indication for excision. Skin lesions, which appear unchanged over time are considered benign.^[9][10] Common systems for digital dermoscopy are Fotofinder or Molemax.
3. Aid in the diagnosis of skin tumors - such as basal cell carcinomas,^[11] squamous cell carcinomas,^[12] cylindromas,^[13] dermatofibromas, angiomas, seborrheic keratosis and many other common skin tumors have classical dermtoscopic findings.^[14]
4. Aid in the diagnosis of scabies and pubic louse. By staining the skin with india ink, a dermatoscope can help identify the location of the mite in the burrow, facilitating scraping of the scabetic burrow. By magnifying pubic louse, it allows for rapid diagnosis of the difficult to see small insects.^[15][16]
5. Aid in the diagnosis of warts. By allowing a physician to visualize the structure of a wart, to distinguish it from corn, callouses, trauma, or foreign bodies. By examining warts at late stages of treatment, to assure that therapy is not stopped prematurely due to difficult to visualize wart structures.
6. Aid in the dianosis of fungal infections. To differentiate "black dot" tinea, or tinea capitis (fungal scalp infection) from alopecia areata.^[17]
7. Aid in the diagnosis of hair and scalp diseases, such as alopecia areata,^[18] female androgenic alopecia,^[19] monilethrix,^[20] Netherton syndrome,^[21] and woolly hair syndrome.^[22] Dermoscopy of hair and scalp is called trichoscopy.
8. Determination of surgical margin of hard to define skin cancers. Examples would be Bowen's disease, superficial basal cell carcinomas, and lentigo malignas. These tumors have very indistinct margins. By allowing the surgeon to correctly identify the true extent of the tumor, repeat surgery often is decreased.

[edit] History

Skin surface microscopy started in 1663 by Kolhaus and was improved with the addition of immersion oil in 1878 by Ernst Abbe. The German dermatologist, Johann Saphier, added a built-in light source to the instrument. Goldman was the first dermatologist to coin the term "dermascopy" and to use the dermatoscope to evaluate pigmented cutaneous lesions.

In 2001, the California medical device manufacturer 3Gen eliminated the need for an immersion fluid with the introduction of the DermLite, the first polarized dermatoscope. This palm-sized instrument reduces examination times and has greatly increased the use of dermatoscopes among physicians worldwide. Although the images produced by the DermLite is slightly different from that produced by the traditional skin contact glass dermatoscope of the past, it is light and compact. A physician can examine 10 times the number of lesions with the DermLite as he no longer has to stop and apply immersion oil, alcohol, or water to the skin before examining a new lesion. Most dermatologists have abandoned the traditional skin contact dermatoscope in favor of the dry dermatoscopes.

[edit] External links

• Dermoscopy images

[edit] References

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