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10 tips for anyone thinking of taking up dermoscopy

Dermatology GPSI Dr Elizabeth Ogden offers advice on taking your first steps into dermoscopy

Dermatology GPSI Dr Elizabeth Ogden offers advice on taking your first steps into dermoscopy

1 A dermatoscope's ability to visualise vascular networks makes it a very useful clinical tool. Using polarised light, or light plus contact with the skin's surface, a dermatoscope enables the vascular network of the top layer of the skin to be seen. Most notably it becomes possible to see the pigment network of melanocytic lesions, which cannot be detected by the naked eye.

2 Deciding which dermatoscope to buy is purely a matter of personal preference. Traditionally, two types of dermatoscope have been available. One is pocket-sized, uses polarised light and does not need to be placed in contact with the skin, thus many moles can be surveyed quickly.

The second, though also handheld, is larger and looks a bit like an ophthalmoscope or auroscope. It has to be pressed gently against the skin and needs a liquid to cut out light reflection from the skin surface. Until recently mineral oil was mainly used, although KY jelly or water would do. But worries about cross-contamination has made alcohol hand gel preferable. However, don't use this on the face as getting it into the eyes will sting – water is best here.

Some dermoscopy enthusiasts work with both pieces of equipment, using the polarised light variety when a patient presents with lots of lesions to look at, then using the contact variety to look more closely at a selected few.

There is now a third variety of dermatoscope – a hybrid that has features of both types combined in one unit.

3 Dermoscopy is a skill, so buying a dermatoscope is just the start. The skill lies in pattern recognition. There are various ways this knowledge can be acquired and it is likely that a combination, if not all, of these will be used. They include attending training courses, online training and, of course, looking at lots of book illustrations.

Using the dermatoscope as often as possible will also help improve one's familiarity with the characteristic appearance of different lesions. Useful websites worth visiting are listed above.

The Primary Care Dermatology Society (PCDS) often includes dermoscopy sessions in its programme of regional educational meetings. Useful websites include Dermoscopy, Dermoscopy.co.uk, International Dermoscopy Society and the New Zealand site DermNet NZ.

4 Owning a dermatoscope is better than sharing. Like a stethoscope or opthalmoscope, a dermatoscope can become a much-used instrument and so it makes sense for each practitioner to have their own, rather than sharing one with colleagues. When a patient presents with a lesion such as a suspicious-looking mole on the back – particularly if this was not the express reason for the consultation – this can be examined straight away if there is a dermatoscope to hand rather than in someone else's room.

5 With training – and regular use of the dermatoscope – accuracy of lesion recognition will improve. It has been clearly and convincingly demonstrated that teaching GPs to use a dermatoscope increases their ability to triage lesions more accurately. Fewer melanomas are missed, there is less surgery for benign lesions, less patient morbidity and fewer lesions referred to secondary care.

6 Dermoscopy is a revelation. The ability to see through the usually opaque stratum corneum using a dermatoscope is truly amazing. Colours become visible and the delicate pigment network of melanocytic lesions can be seen. Vascular structures – the aborising blood vessels in a basal cell carcinoma (BCC) and the purple red lacunae of a haemangioma – are easily seen.

Fascinatingly, a patient's benign moles usually share the same pigment network appearance, making it easier to spot one.

7 Dermoscopy offers the opportunity of earlier diagnosis of skin lesions. A person in the UK with a pale skin now has a one in three chance of developing skin cancer. Fortunately, most of these will be BCCs, which don't metastasise, although melanomas are also on the increase.

In either case early diagnosis is important. For BCCs, this may avoid the need for disfiguring surgery and for melanomas early recognition can literally make the difference between life and death. Deep melanomas have a very poor outcome and there is no proven additional treatment over surgery – radiotherapy and chemotherapy do not seem to have any effect. Dermoscopy provides the opportunity for lesion diagnosis at an early stage and hence the improved prospect of successful treatment.

8 Using a dermatoscope improves patient confidence. Compared with scanning someone's moles with the naked eye, the much more hands-on dermoscopy is both professionally more satisfying and is regarded by the patient as providing a more thorough clinical examination. They often report feeling reassured that their fears are being taken seriously and that they have been ‘properly examined'. Also, when the lesion occurs on some accessible area, like the arm, it may be possible for the patient to view the lesion through the dermatoscope and see the pigmentation for themselves. The most common lesion that is mistaken for a suspect mole is a seborrhoeic keratosis but these have a very specific pattern under a dermatoscope as well as lacking a pigment network. It is very satisfying to be able to reassure a worried patient with a dark lesion that it is completely benign.

9 The terminology of dermoscopy can seem daunting, but the ‘three-step checklist' offers a simple method of deciding whether a lesion should be referred. The checklist looks at just three dermoscopy criteria. These are:

• whether there is asymmetry of colour or structure of the lesion

• the presence of an atypical pigment network – thickened pigment lines or irregular pigment

• whether there is any blue or grey colour.

A score of two or more means that the lesion should be referred.

10 Dermoscopy is actually enjoyable. Like snorkelling, once you have seen what goes on below the surface it is impossible to be content with a superficial view of things.

Dr Elizabeth Ogden is a GP and associate specialist in dermatology in Hertfordshire

Competing interests: none declared

Dermascopic view of a melanoma showing the atypical pigment network and blue-grey 'veil' Dermascopic view of a melanoma showing the atypical pigment network and blue-grey 'veil'

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