Sunscreen Controversies

A recent publication “An update on sunscreens III” made the following useful points regarding some of the current controversies and mis-information regarding sunscreens:

Vitamin D deficiency:

Reviews of the published literature indicate that the topical use of sunscreen protects against skin cancer but does not cause sub-normal vitamin D levels.  A randomised double-blind study by Marks and colleagues demonstrated that daily use of a broad-spectrum SPF17 sunscreen over the summer season was not associated with sub-normal vitamin D levels in Australian adults.  New Zealand researchers have demonstrated that exposure of the hands, face, and neck (10% of skin surface area) for about 3 minutes per day in the Auckland summer (through to about 60 minutes per day in the Invercargill winter) is sufficient to maintain normal vitamin D levels.

Sunscreen toxicity:
A number of studies conclude systemic toxicity of sunscreen in humans has not be demonstrated.  Regarding consumer concerns that nanoparticles in sunscreen might be absorbed into the bloodstream, the Australian Therapeutic Goods Administration states that nanoparticles are not a risk to health.

Sun damage is mainly obtained at the beach:
A prevalent perception is that sunburn occurs mainly during water-based activities, such as at the beach.  However, there is data showing that most people actually get sunburnt during home-based activities such as gardening or other activity around the home.

Vit B3 appears to prevent non-melanoma skin cancer in high risk adults

An Australian study presented at the American Society of Clinical Oncology Annual Meeting in Chicago, suggests the rate of non-melanoma skin cancer is reduced in high-risk patients (more than 2 skin cancers in the past 5 years) by taking oral nicotinamide (vitamin B3).  In this placebo-controlled trial, 500mg twice daily dosing was given for 12 months.  There was a significant reduction in new non-melanoma skin cancers (1.77 vs 2.42 over 12 months).  The treatment is inexpensive and appeared to be as safe and well-tolerated as the placebo in this study.  Reported elsewhere, nicotinamide can cause gastrointestinal upset.  Caution is always necessary basing recommendations on a single study but the findings are very encouraging.
Martin AJ et al.  Oral nicotinamide to reduce actinic cancer: A phase 3 double-blind randomized controlled trial. American Society of Clinical Oncology Annual Meeting, Chicago, May 2015. Abstract 9000.

Confusion regarding conflicting SPF testing on New Zealand sunscreens

A recent Consumer magazine article has reported concerns regarding the reproducibility of sun protection factor (SPF) testing.  Read the online article here.  In general terms, stick with reputable brands, observe the storage instructions and expiry date, shake the product well prior to application, and apply plenty of sunscreen, at least 15 minutes prior to exposure.  Seeking physical protection via shade and clothing is also very important.  Any sunscreen is only a ‘screen’ to reduce, but not block all UV radiation.

Atopic dermatitis (Eczema) news:

Vitamin D for winter eczema
A study of 107 children, aged 2 to 17 years-old has shown a clinical and statistically significant improvement in winter eczema with oral vitamin D supplementation daily for one month.  The study took place in Mongolia - a place where winter vitamin D deficiency is likely, and so the relevance to New Zealand is unclear.  We do routinely see eczema worsens in the winter months when the relative humidity is lower.  As always, the frequent application of moisturisers is critical to the good control of eczema. 

Moisturisers prevent eczema in at-risk babies
Two separate studies involving 242 newborns at risk of developing atopic dermatitis, show that applying simple moisturisers from the first 1-3 weeks of life dramatically reduces the likelihood of the infant developing atopic dermatitis at 6 and 8 months of age.  The risk was halved in the study involving 124 newborns.  Moisturisers used in the study were petroleum jelly, sunflower oil, and a commercial cream or ointment.  This approach appears safe and inexpensive, with the potential for a dramatic reduction in the risk of a disease which causes a significant burden on children, and their families.

The above three articles were published in the October 2014 issue of the Journal of Allergy and Clinical Immunology.

The biology of addiction to the sun

An article published in the medical journal Cell in June sheds light of why humans enjoy the feeling of sunlight on our skin.  It turns out, that when the cells in our epidermis are exposed to UV radiation, DNA damage leads to the polypeptide POMC (proopiomelanocortin) being broken down into various peptides.  One of these peptides stimulates melanocytes (pigment cells) to produce a tan.  Another peptide is beta-endorphin - a feel-good chemical that travels from the skin to the blood stream.  Endorphins are ‘morphine-like’ chemicals which can reduce the transmission of pain signals, and also provide a feeling of euphoria.
From this and other research, sun-exposure appears to have a clear biological potential for addiction; similar to smoking and alcohol.  It is not yet known what effect sunscreen has on UV-induced endorphins.  A subconscious aversion to sunscreen could theoretically occur if sunscreen indeed does block the desired opioid effect.
Skin β-Endorphin Mediates Addiction to UV Light. Fell GL, Robinson KC, Mao J, Woolf CJ, Fisher DE. Cell. 2014 Jun 19;157(7):1527-34.

Auckland UV levels at least as high as Australia

Australia is commonly referred to internationally as one of the highest-risk environments for skin cancer.  New Zealand seldom gets a mention - presumably because of its much smaller size from an international perspective.  However,  even within Australasia, many people falsely assume, the risk and rates of skin cancer are much higher in Australia than New Zealand.  Presumably this is based on assumptions of higher ambient temperatures, and/or sunshine hours.  Interestingly, the environment in New Zealand is at least as dangerous as it is in Australia based on UV indices.  A cooler ambient temperature, and potentially more cloud-cover may in fact, increase the risk of prolonged outdoor exposure and hence skin cancer.  The two tables below demonstrate the maximum UV index levels in Australian cities versus those in NZ.  Interestingly, Auckland equates fairly closely to that of Perth.





Elevated melanoma risk in pilots and cabin crew

According to a recent study published in the journal JAMA Dermatology, pilots have a 2.22 fold increase risk of melanoma, and cabin crew 2.09 fold increase, compared to the general population.  It is known that airline staff are exposed to higher levels of cosmic and UV radiation, but the study does not demonstrate the mechanism of this increased risk.  Further study is needed to investigate this confirmation of what we see clinically in our patients who are pilots. 
Sanlorenzo M et al. JAMA dermatol, published online 3 Sept 2014.

Educating teenagers about sun-protection

As with all public health messages, it is important to convey the desired message in such a way that is likely to achieve a maximal beneficial response.  A recent study in the Journal of the American Academy of Dermatology confirmed what we suspected with regard to educating young people about sun-protection.  50 adolescents (average age 17-years-old) were divided into two groups - one group was shown a video regarding the dangers of melanoma and non-melanoma skin cancer; the second group was shown a video demonstrating changes in appearance caused by sun-exposure (wrinkles, sun-spots etc).  While both groups showed an increase in understanding of the dangers of UV exposure, only the adolescents in the appearance video group actually changed their sun-protection behaviour by increasing their use of sunscreen.
Tuong W, Armstrong AW.  Effect of appearance-based education compared with health-based education on sunscreen use and the knowledge: a randomized controlled trial.  JAAD 2014;70(4):665

How long does the sun-protection message last after a melanoma diagnosis?

A recent Danish study used UV-watches to measure sun-exposure in a group of 21 melanoma patients, and 21 non-melanoma subjects over a three-year period.  Over the three years, the control subjects had stable sun exposure.  In contrast, the melanoma patients gradually increased their sun exposure, and after the second year following their melanoma diagnosis, they were exposing themselves to more UV than the control subjects. 
Idorn LW, Datta P, Heydenreich J, Philipsen PA, Wulf HC. A 3-year follow-up of sun behavior in patients with cutaneous malignant melanoma. JAMA Dermatol 2014Feb;150(2):163-168

Sun protect you, not just your moles

A recent European study regarding the use of sunscreen made the interesting discovery that nearly 5% of those surveyed were applying sunscreen only to their moles.  The intention was to allow a tan without risking the moles turning into melanoma.  The authors remind us that this practice has no scientific basis, and that the application of sunscreen and other sun-protection measures should be on the entire body.  Melanoma and non-melanoma skin cancers often arise in normal skin and therefore sun-protection needs to include all exposed skin to be effective.
Suppa M1, Argenziano G, Moscarella E, et al. Selective sunscreen application on nevi: frequency and determinants of a wrong sun-protective behaviour. J Eur Acad Dermatol Venereol 2014 Mar ;28(3):348-354.

Ongoing need for surveillance following first melanoma diagnosis even with the earliest melanomas (melanoma in situ)

A new study out of Queensland examined the risk of developing a subsequent invasive melanoma after diagnosis of the first.  The relative risk (risk compared with the age-matched normal population) of developing a further invasive melanoma was calculated from data of over 62000 cases. Persons with a first primary invasive melanoma had a risk of 5.4 times normal.  Persons with a first primary in situ melanoma had a risk of 4.6 times normal.  The second melanoma was more likely to occur at the same body site.  This emphasises the need for ongoing surveillance of the skin in any melanoma survivor, even if their first melanoma was of the lowest severity.  The study has been published in the JAMA Dermatology journal and a summary can be found on NZ Melnet.

Daylight-activated Photodynamic therapy

This new technology is based on years of successful experience with traditional red-light photodynamic therapy for superficial skin cancers.  It is a highly effective treatment for precancerous actinic keratoses.  The procedure involves preparation of the skin and application of medication by Dr Gunson, followed by activation of the medication by spending two hours in the daylight.  The treatment is rapid, convenient, and almost painless.  It offers an excellent addition to the available options for treatment of this very common precancerous condition.

Young non-melanoma skin cancer survivors more likely to get other cancers

PHILADELPHIA — People who had non-melanoma skin cancer (NMSC) were at increased risk for subsequently developing melanoma and 29 other cancer types, and this association was much higher for those under 25 years of age, according to a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

“Our study shows that NMSC susceptibility is an important indicator of susceptibility to malignant tumors and that the risk is especially high among people who develop NMSC at a young age,” said Rodney Sinclair, M.B.B.S., M.D., director of dermatology at the Epworth Hospital and professor of medicine at the University of Melbourne in Australia. “The risk increases for a large group of seemingly unrelated cancers; however, the greatest risk relates to other cancers induced by sunlight, such as melanoma.”

Compared with people who did not have NMSC, those who did were 1.36 times more likely to subsequently develop any cancer, including melanoma and salivary gland, bone, and upper gastrointestinal cancers. Survivors younger than 25 years of age, however, were 23 times more likely to develop any cancer other than NMSC. In particular, they were 94 and 93 times more likely to get melanoma and salivary gland cancer, respectively.

“Early detection of cancers through screening of asymptomatic people works best when screening can be targeted at those at greatest risk,” said Sinclair. “Our study identifies people who receive a diagnosis of NMSC at a young age as being at increased risk for cancer and, therefore, as a group who could benefit from screening for internal malignancy.”

Sinclair and colleagues hypothesized that people who develop skin cancers later in life do so as a result of accumulated sun exposure, while those who develop skin cancer at a younger age may do so as a result of an increased susceptibility to cancer in general. To investigate this, they stratified the risk ratios by age and discovered that young people with NMSC are more cancer-prone.  The researchers used data from the All England Record-linked Hospital and Mortality data set collected between 1999 and 2011, and constructed two cohorts: a cohort of 502,490 people with a history of NMSC, and a cohort of 8,787,513 people who served as controls. They followed up with the participants electronically for five to six years, and 67,148 from the NMSC cohort and 863,441 from the control cohort subsequently developed cancers.  They found that for those who had NMSC, the relative risk for developing cancers of the bladder, brain, breast, colon, liver, lung, pancreas, prostate, and stomach remained consistently elevated for the entire period of the study, and the risk for cancers of the brain, colon, and prostate increased with time.

The researchers also found that those who had NMSC before 25 years of age were 53 times more likely to get bone cancer, 26 times more likely to get blood cancers, 20 times more likely to get brain cancer, and 14 times more likely to get any cancer excluding those of the skin.   The risk for developing any cancer subsequent to NMSC decreased with increasing age: 23 times higher risk for those under 25 years of age, 3.52 for those 25-44 years of age, 1.74 for those 45-59 years of age, and 1.32 for those older than 60 years. Thus, although the risk decreased with increasing age, it remained higher compared with individuals who never had NMSC.

This study was funded by the English National Institute for Health Research. Sinclair has no conflicts of interest to declare.

Comment:  Non-melanoma skin cancer presenting in patients under 25 years-old fortunately remains uncommon.  This study however points to the importance of more aggressive health screening is those who do develop skin cancer at a young age.

New vaccine to reduce the occurrence and severity of shingles

The Zostavax vaccine has just been registered in New Zealand.  It is suggested for people over the age of 50 years to prevent shingles, prevent post-herpetic neuralgia (the potentially severe long-lasting pain following the resolution of the shingles rash), and reduce the severity of the acute and chronic pain associated with a shingles episode.  Studies have shown a 70% reduction in shingles attacks in vaccinated people aged 50-59 years, and a 67% and 61% reduction in post-herpetic neuralgia and acute and chronic shingles pain in patients aged over 60 years respectively. 

Shingles (herpes zoster) is the reactivation of the dormant chickenpox virus which 97% of New Zealand adults carry.  One third of people experience shingles in their life-time but the risk increases sharply after the age of 50 years.  Pain is a major feature of the condition and often precedes the skin rash (small blisters on one area and side of the body).  Sometimes that pain persists for many months or years after the rash has resolved and this phenomena is known as post-herpetic neuralgia.

If you are over 50 years old, ask your GP if Zostavax is right for you.   See for more information.

2014 brings a new option for the topical treatment of precancerous sun damage

For many years we have had very successful results with 5-fluorouracil cream (Efudix).  For the first time in New Zealand, a new product became available in January 2014.  Ingeninol mebutate (Picato) is an Australian product based an extract from the milk-weed plant.  Early study results promise similar results to what we are used to with 5-fluorouracil, but with an application time of just three days compared to 2-3 weeks.  Like Efudix, Picato causes skin inflammation in the area treated but this peaks at day 7-8 and resolves by day 14-15 on average.  We are enthusiastic about this new product for the treatment of actinic keratoses, and anticipate it will provide improved convenience for patients.

A wealth of sun, skin cancer, and sun-protection advice specifically for New Zealanders
Check it out at Sunsmart New Zealand’s website.

sunsmart icon

How much sunscreen should you apply?

Ever wondered what quantity of sunscreen you should be applying to get the intended level of sun protection?  The Australian Sunsmart group have developed an online calculator to estimate this based on your height, weight, and type of clothing.  Check it out here.

Results from the latest New Zealand Sun Exposure Survey

The Health Promotion Agency (HPA) undertakes the Sun Exposure Survey (SES) every three years. The purpose of this ongoing research is to collect consistent information on attitudes and behaviours towards sun exposure, to facilitate comparison with historical survey data, and to inform future decision making in the sun safety and skin cancer prevention sector.
The SES was formerly known as the Triennial Sun Protection Survey (TSPS), which had been conducted in 1994, 1997, 2000, 2003 and 2006. Following a review of the TSPS in 2009 the SES was developed, with a focus on the same measures to allow the continued identification of trends over time, and the inclusion of some new questions. The SES is conducted with adults between the ages of 18 and 54 years and teens between the ages of 13 and 17 years.
This report provides an overview of findings for the adult sample (18-54 years) of the 2013 SES. Three types of result are presented in this report: (1) time series results with age adjusted data from the 2010 SES and the first five waves of the TSPS, (2) results comparing questions asked in 2010 and 2013 only, and (3) results for questions that were asked for the first time in 2013. In this report these results are grouped into five key thematic sections: skin type, sun sensitivity and sunburn; outdoor activity; sun protection behaviour; sun protection knowledge; and tanning.

View the report here.

Painful nodule or lump on the ear

It is not uncommon for people to develop a small area on or near the rim of the ear which causes considerable pain when pressure is applied.  This is an important condition to have evaluated by a dermatologist promptly for two reasons.  The two most common causes of this problem are chondrodermatitis nodularis helicus (a pressure-induced inflammation of the skin and underlying cartilage) and squamous cell carcinoma (a potentially aggressive type of skin cancer).  Prompt diagnosis and treatment is especially critical for skin cancer.  With the correct approach, the condition can often be diagnosed and chondrodermatitis cured in one small surgical procedure.  Non-surgical treatments of chondrodermatitis may also be appropriate after assessment, as a first-line strategy.  Relief of pain is important for this condition as well as correcting the underlying cartilage abnormality.  Sleeping on the opposite side is helpful, but it is often not possible to achieve reliably.  The condition starts with chronic inflammation of the skin and cartilage and if left can lead to progressive breakdown of the cartilage.  Dr Gunson utilises a number of surgical and non-surgical modalities for this condition depending on the specific situation.

Excessive underarm sweating (Hyperhidrosis)

Sweating is a natural and necessary body response to provide cooling in hot conditions.  However, when underarm sweating is excessive or experienced at times when it is unnecessary, it can be embarrassing, stressful, and uncomfortable.  It can be a particular problem in both work and social situations, and is often precipitated in times when high performance is required.    Sufferers tend to avoid these situations, and be confined to dark clothing in an attempt to better hide the wet areas.
Fortunately there are effective therapies available to reduce the excessive sweating and get you back into life.  Discuss the situation with your dermatologist.  There are medical treatments and devices which can be effective.  Injectable botulium toxin (eg BOTOX) has been used for over 15 years in New Zealand and Australia for a wide variety of medical indications.  It is often highly successful at managing underarm hyperhidrosis, with the effects of the first treatment lasting an average of seven months.  Dr Gunson offers this treatment and would be happy to discuss the options with you.

Self Skin Examination Guide now available online

A pictorial guide to the easy and very important Self Skin Examination technique is now available. Click here, or on “Self Skin examination” in the navigation bar above.

Advice on sun-protection

Ultraviolet radiation from the sun is well established as the leading cause of skin cancer.  Protecting ourselves from the sun then follows as a critical strategy in the prevention of this highly prevalent disease.  A combination of physical barriers (shade and clothing) and sunscreen is recommended when the UV index is 3 or greater.  In Auckland, the UV index typically only dips below 3 between May and August.  In addition, the UV index is strongly weighed towards UVB radiation, and therefore tends to underestimate UVA radiation which shows much less variation with respect to time-of-day, and time-of-year than UVB.  UVA is the predominant wavelength of sunlight that is thought to cause skin ageing and is also implicated in causing skin cancer.  “I therefore recommend broad-spectrum sunscreen on the face all year round given these factors, and the generally more aggressive and cosmetically sensitive nature of facial skin cancers” says dermatologist, Dr Gunson.

“Based on what we know from treating skin cancers, there are some skin sites that consistently produce high numbers of skin cancers and precancerous sun-damage”.  The top of the nose, the nostrils, the temples, the rims of the ears, the scalp (especially in balding males), the upper cheeks, shoulders, and the back of the hands are all very common sites for basal and squamous cell carcinomas.  Dr Gunson says these upward-facing sites receive a high dose of UV radiation and require special attention when it comes to sun-protection.  He also notes a small number of areas on the head and neck where people are most often surprised a skin cancer has developed.  “The inner corners of the eyes/bridge of the nose, the lower eyelid margin, and the front and back surface of the ears are all places where people are often very surprised they have grown a cancer”.  It may be that we are not as good at protecting these areas because they are not considered as high risk.  Finally, the lower lip is a common site for extensive sun damage (known as actinic cheilitis) and can lead to the development of squamous cell carcinoma which may act very aggressively in this location.

In conclusion, Dr Gunson suggests adding the following to your “slip, slop, slap” routine to maximise your chances of preventing skin cancer and premature skin-aging:

  • 1.Protect your face daily all year-round with an SPF30 sunscreen.

  • 2.Wear sun-glasses to protect your eyes themselves, as well as the surrounding delicate skin.

  • 3.Wear an SPF-containing lip balm and reapply very frequently when outside, as it wears off quickly.

  • 4.Do not neglect to apply your sunscreen to the temples, front and back of your ears, and your whole nose - including the sides of the bridge and nostrils.  Take it right up to the hairline, including the eyebrows.   Reapply sunscreen to the backs of your hands after washing them. 

  • 5.Research consistently tells us, people apply insufficient quantities of sunscreen.  Do not skimp on it, or you will be limiting its protection of your skin.

  • 6.Sunscreen is effective but it is only a filter - not complete protection.  You should therefore wear protective clothing such as long-sleeve shirts, collars, broad-brimmed hats, “rash-shirts”, and sunglasses.

  • 7.If you have a new or changing spot or bump on your skin, get it checked early.

The New Zealand Cancer Society also has useful SunSmart information sheets on their website.

A highly effective treatment for warts

Warts are a very common viral infection of the skin, but are often extremely difficult to cure.  In most cases, the body eventually recognises the Human Papillomavirus (HPV) infection, and the immune system is then able to eradicate the warts.  This may take many years however, and many people are distressed about the appearance and/or discomfort of the warts.  There are a huge number of wart remedies, and the number unfortunately reflects the lack of one or two treatments that work well in most or all cases.  Many treatments are painful or require a large commitment and perseverance on the part of the patient, and still may not offer an effective solution.  Cantharidine however is a physician -applied topical treatment which is painless at application (a significant benefit particularly for children) and highly effective at removing warts with excellent cosmetic results.  It is derived from the blister beetle Cantharis vesicatoria and has in-fact been used for various indications for thousands of years.  Interestingly, one such historic use was as an aphrodisiac, and it is because of this, it has been listed as a restricted drug in New Zealand.  This means it’s importation is controlled by customs and it is a lengthy and expensive process to obtain.  All of this is worthwhile however, as it provides a very effective and safe topical treatment for warts.  It can be used for thin facial warts (where one treatment is often sufficient) through to thick and extensive verrucae on the soles of the feet (where multiple treatments are usually required).  Dr Gunson has used this treatment very successfully for many years.  If you or your children suffer from problematic warts, consider asking if this treatment is a good option.

Mohs surgery represents the most cost-effective treatment for skin cancer

This was the conclusion of a study recently published in the medical journal “Dermatological Surgery”.  The research was led by Dr Larisa Ravitskiy from Ohio State University in Columbus, and involved 406 tumours treated with Mohs micrographic surgery (MMS).  The costs were compared with those of subsequent re-excision and reconstruction of tumours that were recurrent following treatment with other modalities.  The author notes “The common misperception of MMS as an expensive option has its roots in the poorly understood bundled reimbursement of the procedure, which includes costs of surgical excision, histology preparation, and pathology”.
Dermatol Surg 2012;38: 585-94

Under the sun

While a sunny day does a huge amount for our physical and psychological well-being, we know exposure of our skin to too much sun can have major detrimental effects.  The UV radiation emitted by the sun is the major cause of aging of the skin, and DNA damage of the cells making them prone to the development of skin cancer, often years later. 
In addition, UV radiation suppresses the local immune system of the skin.  Our immune system not only protects our bodies from infections, it also patrols the skin for DNA damage and destroys badly damaged cells prior to their progression to skin cancer.  This means the sun we get today may allow the sun-damaged cells we have from years previous, to finally progress into cancerous growth.  This is one reason we tend to see more people presenting with skin cancers during the summer months. 
Enjoy sunny days, but first protect your skin from the damaging UV rays by use of shade, clothing, hats, sunscreen and sunglasses.

Tomatoes and the skin

Lycopene is the red pigment responsible for the colour of tomatoes.  This chemical has powerful antioxidant effects and has been shown to reduce the damage UV radiation does on the skin.  There is also preliminary research showing it may help reduce the risk of some human cancers.  It is not available in raw tomatoes but is released on cooking and is therefore found in high concentration in tomato paste.  It has not been shown to reverse photo-aging but may help prevent it.  A good excuse for another slice of pizza?