Sun Exposure and Moles by Dr Sandeep Cliff, The Cadogan Clinic

Sun exposure

The recent summer weather and the opportunity to relax in sunnier climes has given us all an opportunity to expose our skin to the sun, and thus to ultraviolet radiation (principally ultraviolet A and B). Sunbathing has also allowed us all to look at our moles and those of people close to us. Although doctors clearly recognize the health benefit of sun exposure which include Vitamin D production (good for bones and teeth) and the boost that sunlight gives to us with regards to our mood and mental wellbeing – we are also increasingly seeing the downside of excess sun exposure in the form of sunburn with the long term consequences of skin cancer and premature ageing of the skin.

It is for this reason that dermatologists advocate limiting the sun exposure the skin gets, ensuring that an adequate amount of sun cream is applied ( of at least SpF 15 or more) and that this is applied regularly to the entire exposed skin. We also recommend that one should avoid the peak sunlight exposure (the hours of 11 am to 3pm daily). Further to this we recommend that everyone should undertake a comprehensive skin examination on a monthly basis looking for a changing mole and if one is detected to seek medical advice as soon as possible. To help with recognizing the worrying features of moles I have written a brief explanation of what a mole is and what features should be looked for when examining a mole.

Moles

What is a mole? A mole is a collection of pigment cells present within the skin. These cells are known as melanocytes. Sometimes moles are referred to their scientific term melanocytic naevi. They are extremely common. Most people are born with a few moles and develop others during their lives. They vary in size from some barely visible to large, covering virtually the entire body (termed bathing trunk naevi).

What causes moles? Most moles are simply the result of a harmless overgrowth of the pigment cells within the deeper layer of the skin. Most moles develop spontaneously or are caused by exposure to sunlight and tend to appear on those areas of the skin that catch the most sunlight – usually the trunk, arms and legs. Most of these moles appear during the first 20 years of life, although they may continue to develop into the 30s and 40s. However, the majority disappear with age.

Why are moles a concern? The main worry with moles is that a small number may go on to develop a form of skin cancer called malignant melanoma. This form of skin cancer, which can be fatal, is best spotted early and treated with surgical excision (i.e. it is cut out of the skin).

Who is at risk? The presence of moles should not cause you serious problems but large numbers, more than 25, are an indication of susceptibility to melanoma. So you should take great care about exposure to sunlight. If there is a family history of malignant melanoma, you should be particularly vigilant about checking moles.

What are the symptoms of malignancy? The mole is itchy and painful – for no obvious reason. It might have increased size or an increasingly irregular appearance, especially at the edges. Also a change in color, particularly if the mole gets darker or becomes mottled.

Also watch for spontaneously bleeding and satellite pigmented lesions i.e. new moles develop and extend beyond the original mole.

How is malignancy diagnosed? Although most changes in the size, shape and color of moles are due to a benign, non-cancerous increase in number of pigment cells, any mole that looks unusual should be examined. Your doctor will probably request information on recent changes to the mole along with a family history to assess your risk.

What next?

If only mild changes are found, your doctor will usually only need to take a clinical photograph of it or measure it and ask you to keep an eye on it. The mole's appearance may be reviewed in a later appointment. But if your doctor is concerned then they may choose to refer you to a skin specialist (dermatologist) for assessment and possible removal.

Another popular and very effective means of monitoring moles is to map them using a mole mapping system. This is usually undertaken by a dermatologist and allows moles to be examined and then photographed digitally. A copy of the mole can then be stored on a hard drive and a copy presented to the patient for future reference. It is both a useful technique for self monitoring of moles but also permits the clinician to have a baseline when examining and assessing an individual’s moles.

Dr Sandeep H Cliff BSc FRCP

Dr Sandeep H Cliff BSc FRCP is Consultant Dermatologist and Aesthetic Dermatologist at The Cadogan Clinic, 120 Sloane Street, London SW1X 9BW www.cadoganclinic.com