Skin self examination – checking yourself for skin caner

A guide to checking your own skin for early signs of skin cancer by Midland Skin

Why examining your skin matters

A large number of skin cancers, including melanoma, are first detected by patients or family members rather than by a doctor. This is why regular self-examination is important and can help skin cancer be detected at an earlier and more treatable stage. It is particularly important if you are at higher risk of skin cancer. Skin self-examination should be carried out monthly, either alone or with the help of a partner.

Who is at higher risk of skin cancer

Some people benefit from more vigilant self-examination than others. You are at higher risk of skin cancer if any of the following apply:

• Fair skin, light hair, or light eyes
• A personal history of skin cancer or pre-cancerous lesions
• A first-degree family history of melanoma
• A history of blistering sunburns, especially in childhood
• A history of tanning bed use
• A large total number of moles (more than 50)
• The presence of several atypical (dysplastic) moles
• Long-term immunosuppression, including following an organ transplant
• Outdoor occupation or significant lifetime sun exposure

If two or more of these apply to you, a baseline skin check with a Consultant Dermatologist is recommended.

What is a mole?

Moles are harmless skin growths formed by a collection of skin cells called melanocytes. Melanocytes produce melanin, the pigment which gives colour to the skin, and this is why many moles are brown. Most moles develop between the ages of 5 and 30, mostly around puberty. The average young adult has around 20 to 30 moles. Moles tend to fade in later life, and the average 70-year-old may only have 5 to 10.

A mole may be medically referred to as a melanocytic naevus (plural: naevi). The main types of benign mole are:

• Junctional naevus – a flat mole
• Compound naevus – a raised mole
• Intradermal naevus – a very fleshy, raised mole
• Dysplastic naevus – an atypical mole, discussed below

Melanoma is a cancer that arises from melanocytes and is not itself a benign mole subtype, although it can develop within an existing mole.

What do normal moles look like?

No two moles are exactly the same, even within the same person. Moles usually have an even brown colour, are symmetric, and are well-defined. Some moles may have a hair growing through them, and this is reassuring rather than concerning. In later life, moles may start to lose their colour and become fleshy, especially on the face.

The ABCDE rule for checking moles

Features to look for in a mole that may suggest it has become cancerous are:

• A – Asymmetry. Does one half of the mole look the same as the other half?
• B – Border. Are the borders of the mole clear and sharp, or do they look blurred, jagged, or irregular?
• C – Colour. Are there more than two tones of colour? Is the colour haphazardly variable, or is it even?
• D – Diameter. Is the mole greater than 6 mm in diameter?
• E – Evolution. Is the mole changing? Has it grown or changed in colour in the last 3, 6, or 12 months? Or is it new?

Of these features, evolution is arguably the most important. A mole that is clearly changing warrants assessment regardless of how it scores on the other four criteria.

The Ugly Duckling sign

Most moles on a single person tend to resemble one another. The Ugly Duckling sign refers to a lesion that looks visibly different from its neighbours – larger, smaller, darker, lighter, or simply out of keeping with the rest. An isolated lesion with no neighbours to compare it to is also considered an Ugly Duckling. Studies show that this single comparative check is one of the most reliable ways for non-clinicians to spot a suspicious lesion, and it is particularly useful for those with many moles.

Atypical (dysplastic) moles

Atypical moles are benign moles that have one or more features resembling a cancerous mole. They may be irregular in shape, irregular in colour, or larger than 6 mm. There is a modestly increased risk that some atypical moles will undergo malignant change, and the risk rises further in people with five or more atypical moles. Depending on the appearance, your Consultant Dermatologist may recommend either monitoring or removal.

Signs of basal cell and squamous cell skin cancer

Most skin cancers are not melanomas but basal cell carcinoma (BCC) or squamous cell carcinoma (SCC). These do not always present as a pigmented lesion and are easy to overlook during a self-examination. Watch for:

• A pearly, translucent, or shiny bump that may bleed or scab over and reform
• A rough, scaly, red patch that does not resolve
• A sore that fails to heal within 4 to 6 weeks, or one that repeatedly heals and breaks down
• A firm, tender nodule, particularly on sun-exposed sites such as the head, neck, ears, or backs of the hands

Any of these warrant assessment by a Consultant Dermatologist.

Where on the body skin cancer commonly appears

Skin cancer can occur anywhere, but some patterns are well-established:

• In men, melanoma most commonly appears on the back
• In women, melanoma most commonly appears on the lower legs
• BCC and SCC most commonly occur on chronically sun-exposed sites: face, ears, scalp, neck, forearms, and backs of the hands
• Acral melanoma can occur on the palms, soles, and under the nails, regardless of sun exposure

Skin self-examination in darker skin types

Skin cancer is less common in darker skin types, but it does occur, and the distribution is different. In Black, South Asian, East Asian, Middle Eastern, and Hispanic skin types, melanoma is disproportionately likely to appear at sites that receive little or no sun:

• The palms and soles
• Under the fingernails and toenails
• The inside of the mouth and other mucosal surfaces
• The genital region

These sites are easy to miss and should be included deliberately in every self-examination.

Nail and acral examination

The nails should be checked at least once a year with all polish removed. Watch for:

• A new longitudinal pigmented band running the length of the nail (longitudinal melanonychia)
• A pigmented band that is widening, darkening, or has irregular edges
• Pigment that extends from the nail onto the surrounding cuticle or skin (Hutchinson’s sign)
• A non-healing ulcer, lump, or change at the nailfold

Any of these features warrant urgent specialist assessment.

How to check your skin: a step-by-step guide

You will need a full-length mirror, a hand-held mirror, and bright natural light. Work methodically from the scalp down to the soles, both looking and feeling the skin as you go. A partner can be very helpful for the back, scalp, and other hard-to-see areas.

Step 1. Face and neck. Check your face in the mirror, paying close attention to the forehead, nose, lips, and cheeks. Look and feel the tops of the ears and behind them. Look and feel the front and sides of your neck.

Step 2. Scalp. Run your fingers through your hair, looking and feeling for any lesion. A hair dryer is helpful to part the hair and expose the scalp section by section.

Step 3. Arms and hands. Start with your hands. Examine your nails for streaks or irregularity, the palms and backs of the hands, and between the fingers. Work upwards along the forearms and upper arms, and lift each arm in turn to see the underside right up to the underarm.

Step 4. Chest and abdomen. Inspect your chest and abdomen, including under the breasts and the flanks.

Step 5. Front of legs. Inspect the front and sides of your thighs and lower legs.

Step 6. Back of the body. Use a hand-held mirror to inspect the back of the torso, starting at the nape of the neck and working down through the back, buttocks, and back of the legs. A partner is helpful for this step.

Step 7. Feet and groin. Sit down. Inspect the tops of the feet, between the toes, the toenails, and the soles. Inspect the inner thighs and the groin.

Areas commonly missed

Patients consistently overlook the same handful of sites:

• The scalp
• Behind the ears
• The eyelids
• Between the toes
• The soles of the feet
• Behind the knees
• Between the buttocks
• The genital region

These should be added to your routine deliberately each month.

Photographing and tracking change

A baseline set of photographs is invaluable for identifying change, particularly if you have many moles. Use your phone to take wide shots of each body region in good natural light, and close-ups of any individual lesion you want to keep an eye on. Where possible, include a ruler or a coin for scale. Repeat the photographs at the same time each month and compare side by side. Dedicated skin-tracking apps can help, but a simple folder of dated photos works equally well.

Skin self-examination FAQs

What to do if you find something concerning

Report any lesion that grows, develops an irregular outline, changes colour, bleeds, crusts, scabs, fails to heal, or becomes itchy, painful, or otherwise different from the rest of your skin. The earlier a melanoma or non-melanoma skin cancer is identified, the simpler and more successful treatment is likely to be.

A baseline mole check with a Consultant Dermatologist is the most efficient way to establish what is normal for you and to flag anything that is not.