FAQs
We present a number of frequently asked questions. If there are any specific queries you have, or if you'd like to see additional questions answered on this page, please contact us.
Dermoscopy FAQs
What is the difference between epiluminescence microscopy, dermatoscopy and dermoscopy?
There is no difference at all, just different names for the same technique. In 2001 at the 1st World Congress of Dermoscopy the various terms were discussed and it was decided that in order to unify the terminology particularly with respect to research the term “Dermoscopy” should be used.
Why should a dermatologist start doing dermoscopy?
Dermoscopy is a fusion of the two major principles that facilitate good skin examination, namely magnification and illumination. By using dermoscopy dermatologists will be forced to examine individual lesions more closely. Their diagnostic accuracy for diagnosing not only pigmented skin lesions and melanoma, but also a whole variety of dermatoses, including infections and inflammatory conditions will increase, with time and training.
As with all aspects of medicine, diagnostic accuracy increases with experience, takes time and perseverence. We suggest that doctors beginning with dermoscopy should initially rely on as usual their clinical judgement and should start to use dermoscopy for unequivocal lesions only. In this way their familiarity with dermoscopic features will gradually increase. Attending a course or meeting in dermoscopy will increase your confidence in dermoscopy and will increase your diagnostic accuracy particularly for pigmented skin lesions in general and early invasive melanoma, including melanoma in-situ. By looking at other dermatoses with dermoscopy repeatable features can be seen that are otherwise invisible with the naked eye, e.g. the scabies mite will no longer be able to hide!
Do we still need histopathology when performing dermoscopy?
Dermoscopy is a non-invasive clinical method that is currently used to supplement the traditional clinical diagnosis, not replace it. With dermoscopy, morphological features that cannot be detected by the naked eye alone become visible. Therefore, dermoscopy opens up a new dimension of clinical morphology that can be regarded as the missing link between clinical morphology and histopathology. Nevertheless, when a pigmented skin tumour is excised, conventional histopathological examination is still recommended.
What are the limits of dermoscopy?
Dermoscopy allows visualization of the horizontal plane of a given skin lesion only to the level of the papillary dermis. Pathologic structures situated in the reticular dermis cannot be visualized at all (like with the naked eye). Heavily pigmented skin lesions are sometimes very difficult to diagnose, and hypopigmented or amelanotic melanoma represents a particular diagnostic challenge. Very thick tumours may lack a number of dermoscopic features and thus clinical experience and clinical diagnosis remains very important in these lesions. If diagnostic doubt remains with dermoscopy then the lesion should be biopsied. Dermoscopy is not 100%, so do not expect it to be!
What type of dermatoscope is better?
Oil immersion dermatoscopes have a longer history of use in dermatology, however the inconvenience of applying an oil or interface fluid (alcohol gel or ultrasound gel) makes these instruments time consuming when multiple lesions are being examined, and also raises the question of cross contamination as they involve contact with the patient. They have a bright image and usually a heavy handle.
Cross-polarised light dermatoscopes are becoming very popular with dermoscopy enthusiasts as they are now of a suitable quality that the device brightness is comparable with the oil immersion instruments. They are more expensive, however they are more versatile, smaller and lighter, and multiple lesions can be examined quickly without the need for interface fluid application. Newer devices have an extendable faceplate for use with interface fluid if needed, for instance looking at hyperkeratotic lesions.
Ultimately the choice of dermatoscope will reside with the doctor and include factors such as personal preference, and likely population of patients to be examined. Note, some dermoscopic structures are seen differently with the two types of devices, and it may take some time to get your eye in with the new device. Both instruments are battery operated therefore do not forget to keep them fully charged!
What type of immersion oil is best used for the oil immersion dermatoscopes?
Alcohol gel is preferred, as it should be easy to hand in the examination room and will reduce the theoretical risk of cross contamination. Around the eyes and nails ultrasound gel is beneficial as it will not irritate the eye and does not run off the nail (Note, do not forget to clean the instrument with alcohol gel if ultrasound gel was used).
For the instruments with cross-polarised lenses there is no need for immersion oil; however care should still be taken to keep the instrument clean and to avoid cross contamination between patients.
What magnification is the best used for dermoscopy?
A 10-fold magnification is standard and works well for diagnosing pigmented skin lesions. With digital cameras the magnification can be enhanced digitally which may help when visualising blood vessels in tumours.
What camera should I buy to take dermoscopic images?
Both types of hand held dermatoscopes can usually be connected to digital cameras, either directly, via a screw thread, or via an adapter ring. Cameras and dermatoscopes vary and may not be compatible, therefore please contact the manufacturer of the device for specific recommendations. The cross- polarised devices may need to be placed in contact with skin to avoid camera shake, the newer devices have an extendable faceplate for this purpose. Again consider the risk of cross contamination.
Will computer mole mapping substitute diagnosis by an experienced dermatologist?
Research into this field is increasing. At present the computer machines have limitations including:
• Low image resolution compared with hand held devices.
• High cost and very bulky compared with hand held devices.
• Software limitations (good with very clear melanomas, not so good with thin / early / small melanomas or hypopigmented melanomas.
• Difficulty with hyperpigmented benign skin tumours.
• Difficulty with visualising blood vessels in tumours as contact is required in the majority of devices.
• A higher magnification (digitally x20 –x50) is often promoted as an advantage, however due to the initial lower image resolution there is no advantage over a hand held x 10 image that is digitally magnified.
• Can only comment on lesions preselected for examination.
However they also have some advantages including:
• Facilitating easier follow up of patients.
• Numerous naevi can be catalogued easily.
• Follow up images are standardised for magnification and brightness, and therefore easily compared with earlier images taken with the same device.
Therefore we would not recommend their use for diagnostic purposes alone; however they are very useful in the follow up of patients.
In summary they will not replace dermatologists but will be an increasing part of dermatology practice particularly in the follow up of patients with multiple naevi.
Miltex FAQs
How do i sterilize Miltex instruments
Apply 134 C for 3 minutes in an autoclave for instruments.
Miltex sterilization guide for aluminum hand is 132 C for 4 minutes.
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