More evidence for the role of topical silicon in wound healing

The role of silicon in wound healing and scar treatment is well established. The initial discovery that scar tissue more readily loses water than normal skin was made incidentally during research for eczema. Silicon sheeting was designed which was found to help improve scar tissue symptoms and appearance. Later, silicon gel was designed to provide the same benefits but in a much more user-friendly form.

Dr Gunson has used these products for many years for new surgical and traumatic wounds, superficial wounds, and scarring. Most silicon products are not licensed for open wounds, or application to broken skin. Swiss manufacturers, Stratpharma however offer a range of silicon gel products, including one licensed for use on broken skin and open wounds.

Further evidence for the benefits of topical silicon in open wounds has just been published in the Clinical and Experimental Dermatology Journal (2018 43:718-37). The authors presented three patients who had undergone skin tumour excision on the scalp and extremities where the decision was made to allow the wounds to heal on their own, without sutures (termed second intention healing). The first case involved a scalp where the bone and it's covering periosteum was exposed. Usual wound care was applied but at day 15, the wound healing was not progressing well with non-viable tissue and a persistence of uncovered periosteum. Stratamed (Stratpharma) gel was then applied regularly to the wound and within 3 days, healthy granulation tissue (new vascular healing tissue) appeared, and complete healing progressed quickly thereafter. Two other cases were reported when the same gel was applied from day one and total healing time was reduced from the time usually expected (around 7 weeks for scalp wounds with exposed periosteum). The authors did not disclose any industry involvement, sponsorship, or other conflict of interest.

More information regarding silicon gel can be found

The much anticipated Dermapen 4 MD has arrived

After an extended delay, we are pleased to have taken delivery of the brand new Dermapen 4 MD. This is a significant upgrade on our previous Dermapen 3 MD dermal microneedling device. There are 12 new features marketed on the new device. From our point-of-view, the most important are:

1. A new "scar treatment" setting which extends the depth of microneedling to 3 mm for stubborn scarring. Depth is digitally programmable in 0.1 mm increments for precision.

2. A 33% increase in microneedle density. The number of needles per disposable treatment head is increased from 12 to 16, creating more rejuvenating channels and more efficacy.

3. Oscillation speed is also increased up to 120 revolutions per second. This translates to a 1920 holes per second; 47.9% more than its Dermapen 3 predecessor.

4. Battery powered operation. This allows much improved convenience, manoeuvrability, and speed.

5. Improved treatment head design to automatically calibrate for precise reproducible needle depth, minimise drag and fluid build-up, as well as prevent any possibility of fluid cross-contamination.

The dermal microneedling process is now a well-established effective and safe skin procedure. Our most common indications are
scarring (old, new, acne, surgical, stretch-marks) and rejuvenation of age and sun-related skin damage (fine lines, wrinkles, dullness, and pigmentation).

For more information
click here.

Merkel cell carcinoma

There are numerous types of skin cancer. The three most common types are basal cell carcinoma, squamous cell carcinoma, and melanoma in order of incidence. These account for the vast majority of skin cancers.

Merkel cell carcinoma is one of the more rare types. It is about 30 times less common than melanoma in the US. However, diagnosis rates have been increasing recently. The reasons for this are unclear but it may in part be due to increased awareness of the signs and symptoms. Merkel cell carcinoma is an aggressive skin cancer and its prognosis is far better if it is picked up an a very early stage.

Some of the issues making Merkel cell carcinoma so dangerous are its rapid growth, tendency to spread (metastasise) early, and its relatively non-specific clinical features. We have the well-established
ABCDE criteria to help us all identify melanoma but knowledge of Merkel cell carcinoma is poor. An easily remembered acronym to help identify Merkel cell carcinoma was devised by a group who reported their findings in the Journal of the American Academy of Dermatology in 2008. Their AEIOU acronym is as follows:

A: Asymptomatic (generally not sore, bleeding, itchy etc)
E: Expanding rapidly (will grow quickly over weeks to a month or two)
I: Immunocompromised (people with HIV, chronic lymphocytic leukaemia, medication suppressing the immune system, organ transplant recipients are at much higher risk). However, 90% of patients do not have these issues
O: Older than 50 years (the incidence gets higher with every decade)
U: Ultraviolet-exposed fair skin

Almost 90% of Merkel cell carcinoma patients have 3 or more of these criteria. However, there are a number of other diagnoses that can share some of these features so not every skin bump with these signs is a Merkel cell carcinoma. An benign inflamed cyst or lipoma (fatty growth) or another skin cancer could present in a similar fashion.

However, if you or a family member has a bump that rapidly expanding like this, it is prudent to have it reviewed promptly and biopsy considered. Photos and further information about Merkel cell carcinoma can be found at:

Sun protection advice based on UV index may not be correct

International health agencies recommend that no sun protection is necessary when the UV index is under 3. However, new data from a New Zealand NIWA research group published last month ( reports) raised significant questions about the validity of this advice.

The issue is that the UV index value of 3 was chosen as the level of UV intensity which will lead a fair skin person to burn after one hour of exposure. This assumes no one spends more than one hour at a time outside, which is clearly flawed. Their data suggests that similar skin damage can be done from a long exposure at low UV dose, as is seen in short exposure at a higher UV dose.

This sits somewhat contrary to data about the body's ability to adapt to low dose sun exposure reported in this blog on 4 February 2017 below. The current study quotes recent evidence that there is a measurable increase in DNA damage from small increases in UV exposure even at low level. The February report however looked at a reduction in DNA damage with time, suggesting the body can adapt over a period of weeks if the exposure levels are low. The beauties and controversies of medical science!

They do raise another interesting observation. In winter, UV exposure to the face and neck is higher than the UV index would suggest. This is a result of the sun sitting lower in the sky, and therefore more dose hits these vertical surfaces than it does the horizontal surface that is used to measure the UV index.

What people want in the treatment of skin cancer

A recent study published in the medical journal, Dermatologic Surgery investigated patient preference in the treatment of the most common type of skin cancer, basal cell carcinoma. They reviewed six studies on the subject.

In four of the six studies, recurrence of the tumour was rated the most important attribute. Cosmetic appearance of the area after treatment was rated most important in one study, and the second most important in three studies.

This information is not surprising but highlights the utility of Mohs micrographic surgery for appropriately selected skin cancer lesions. Mohs surgery offers the lowest recurrence rates for these cancers and because it also specifically allows for the sparing of normal surrounding tissue, the defect size and subsequent reconstruction/scar can be minimised for the best cosmetic result. Additionally, recurrent tumours will require further surgery at a later date resulting in a larger defect and reconstruction. Also, recurrent tumours are more difficult to clear, have lower cure rates, and are more technically difficult to reconstruct.

Therefore, the first chance to treat is always the best chance to minimise the recurrence rate, and maximise the cosmetic outcome.

Stimulate your skin to rejuvenate itself

You may have read in the media this week that a number of people, including celebrities, are requesting removal of cosmetic implants and fillers. It is a reminder of the sense behind stimulating your skin to rejuvenate itself with its own natural collagen and elastin, rather than injecting or implanting foreign substances in order to simulate a younger look.

Sure, the injectables produce a faster and more pronounced result. However, if you are willing to wait for your skin to produce its own collagen and elastin after stimulation by dermal needling, you get a very natural and lasting result. You will also never be faced with wanting to remove a foreign substance at a later date because it is causing unwanted effects, or hasn't produced the natural look you are after.

Tell your skin to produce more of the natural components it had when it was younger. More information on dermal microneedling is available

Using heat to detect skin cancer

With skin cancer being such a major health issue in New Zealand it is always pleasant to read people are working on ways to improve challenges in the diagnosis of this disease.

In a recently published paper in the journal Skin Research and Technology, Magalhaes and colleagues reviewed the literature to date on the use of infrared thermal imaging for the diagnosis of skin cancer. This picks up subtle differences in temperature between benign and malignant skin lesions, presumably based on increased blood flow in the malignant lesions.

This non-invasive technology may be a promising tool for the identification of early skin cancer, hopefully in the not-too-distant future.

Reflected UV not as big as we thought

We have always been led to believe the UV radiation reflected off the water and sand when at the beach, or out on the water is part of the reason we are more prone to sunburn when undertaking these activities.

Interestingly, a recent study in the medical journal Photodermatology Photoimmunology Photomedicine (March 2018) concluded that in fact the vast majority of the sun's UV radiation passes into the water, and very little is reflected especially when the sun is high in the sky (the time when the UV level peaks). We certainly notice the reflected light with our eyes, but the reflected UV does not appear to have a major bearing on our skin.

The corollary of this fact is of course that we are still exposed to almost the same UV when we are swimming under the water as when sitting on the beach. The UV index was only reduced to half by a depth of two meters under the surface.

Adequate shade and protection from the sun above remains the priority when enjoying the beach or water sports.

The 'ugly-duckling' sign in melanoma

Self skin examination is very useful for detecting melanoma. In 1985, the ABCD acronym was introduced to help people identify suspicious moles themselves.

A = Asymmetry
B = Border irregularity
C = Colour irregularity
D = Diameter > 6mm

The E was a later but very important addition.

E = Evolving (changing)

Since that time, many of us have changed the D from diameter to DIFFERENT (i.e an 'ugly-duckling' mole that looks different for any of your other moles).

A late 2017 study reported in the Journal of the American Academy of Dermatology tested the utility of just the Ugly Duckling sign versus the ABCD acronym for simulated moles in 101 adult volunteers. The ugly duckling sign demonstrated superior accuracy of melanoma recognition, and better specificity than the ABCD group.

This is a simulated study in a relatively small number of participants, but it underlines the usefulness of a very simple tool that may increase the pick-up of melanoma by all of us. We tend to teach the whole ABCDE (with D as different) but given this data, possibly using just the D on its own is easier and more effective.

Does a higher SPF sunscreen provide better protection?

A lot has been written lately about sunscreens in the medical literature and the press. One comment you will read frequently is that there is very little benefit to an SPF (Sun protection factor) higher than SPF30. The basis behind this advice is scientifically sound.

Approximate UVB ray blockade:

SPF15 sunscreens block 93%
SPF30 sunscreens block 97%
SPF50 sunscreens block 98%

Looking at these figures, it would certainly seem reasonable to conclude, increasing SPF above 30 provides very little additional benefit.

However, standard SPF laboratory testing that dictates a sunscreens SPF rating is very different from how sunscreens are used in real life. Multiple studies have confirmed the fact that we do not apply our sunscreen anywhere near as thick as in the standardised SPF testing protocol (2 mg/cm2). When we apply our sunscreen at the beach, we are likely to be getting considerably less protection than the product provided in the laboratory setting. Therefore, using a higher SPF rated product will help cover the difference between testing and real-life usage.

This has now been proven in a December 2017 study published in the Journal of the American Academy of Dermatology. Nearly 200 people were randomised to apply a SPF50 sunscreen to one side of their face, and a SPF100 sunscreen to the opposite side of their face without knowing which was which. No advice was given as to the amount, or how to apply the sunscreen, so the experiment was closer to representing real-life usage. Independent and the subjects' own assessment of sunburn scores following sun exposure both showed significantly higher sunburn on the SPF50 side of the face compared to the SPF100 side.

There is also a second reason why a higher SPF sunscreen is likely to be more desirable. Broad-spectrum sunscreens (which are universally recommended as the best) can only be labelled 'broad-spectrum' when their UVA protection is at least 30% of the UVB protection (the SPF rating is based on UVB testing alone). UVA is a longer wavelength radiation present in the sun which has been implicated in both skin cancer and sun-damage to the skin. A higher SPF sunscreen therefore offers a higher UVA protection and therefore better broad-spectrum protection.

Sunscreens are only filters and do not block all of the sun's harmful radiation. They should be used in conjunction with other sun-protection behaviours such as seeking shade, using clothing and sunglasses, and keeping out of the sun in the middle of the day when the UV levels are at their highest. However, it seems higher SPF rated sunscreens do indeed offer increased protection when used in real life.

What is a Physician and does this differ from a Specialist?

The terminology used to refer to medical practitioners is becoming increasingly confusing. The word Specialist is often used to mean a variety of qualifications or special interests of a doctor. Physician is another term that is easily misunderstood.

What is a Physician?

In Australasia, a physician is a medical specialist who has completed at least six years of additional training in a medical specialisation after their medical degree and internship. In some countries (such as the United States of America) the term Physician is interchangeable with medical practitioner. This is not the case in New Zealand and Australia.

Specialist versus Physician?

All Physicians are Specialists, but not all Specialists are Physicians. Physicians training and accreditation is under the
Royal Australasian College of Physicians (RACP). The term "Skin Specialist" is sometimes used by those without Dermatology Specialist training.

So what is a Dermatologist?

Every Dermatologist trained in New Zealand is a RACP specialist Physician. They are also all Fellows of the New Zealand Dermatological Society (FNZDS). Further information is available at the website of the
New Zealand Dermatological Society Incorporated.
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Why is the risk of skin cancer so high in New Zealand?

If you talk to those who travel, it is widely noted that the intensity of the sun in New Zealand is significantly higher than that in North America or Europe. In fact, a NIWA study has shown that our UV index is approximately 40% higher than similar latitudes in the northern hemisphere.

It is interesting to note in the recent publication of the NZ Health Promotion Agency (New Zealand Skin Cancer Primary Prevention and Early Detection Strategy 2017 to 2022) the following three reasons are listed as the main causes of the difference in UV index intensity:

1. Our clearer, unpolluted skies (a 20% effect)
2. Our lower ozone levels (a 7-10% effect)
3. The reduced distance between us and the sun during our summer compared to a northern hemisphere summer due to the elliptical orbit of the earth around the sun (a 7% effect)

The full document can be read at

How exercise may lower cancer risk

The New York Times reported on an interesting study into how exercise may protect us from the development of cancer. The study was published in the journal Cell Metabolism and involved laboratory mice with melanoma. The mice that were provided with running wheels developed far less melanoma and metastases than those mice that remained sedentary.

They found higher levels of adrenaline, interleukin-6 (IL-6), and natural killer (NK) cells in the exercising mice. NK cells are immune cells with a known cancer-fighting ability. It seemed from their study that the increased blood levels of adrenaline in the exercising mice, primed their IL-6 producing cells to activate the NK cells. More data is needed to prove the same mechanism occurs in humans, but other studies have shown adrenaline and NK cells are both increased by moderate exercise in humans.

Exercise is good for our body and mind in so many ways. This interesting study provides further evidence of its benefits.

The full article is available