Western Skin Institute Skin Blog is a platform to keep you, the patient updated on latest news about the skin and useful information on looking after your skin. All information are written by dermatologists for the lay public. We hope you'll find the information useful and that you will share it with all your friends and family.
Skin blog 6 - January 2017 - How safe are sunscreens? (and a note on how to spot fake news!)
We are yet facing another wave of Facebook posts of fake news where sunscreens are considered ?unsafe? or ?cancer causing due to nanoparticles?. This blog hopes to bust the misinformation and present the evidence. For busting myths of ?spray-on sunscreens? see earlier blog (below this article).
What are nanoparticles?
Nanoparticles are fine particles in the range of 100 and 2500 nanometers. Nanoparticles are in between the size of bulk molecules (such as a red blood cell) and the size of an atom.
Source: Chemical Communications: Chem. Commun., 2006, 941-949
Nanoparticles are not new. They have been used since the 9th century in Mesopotamia when artisans used these to generate a glittering effect on the surface of pots. This lustre is due to the film containing silver and copper nanoparticles in the glassy matrix of the ceramic glaze.
Why are nanoparticles used in sunscreens?
Bulk forms of zinc oxide and titanium dioxide have been used for decades. Their main disadvantage is that they are visible on the skin as an opaque layer ? hence the comment, "looking like a ghost?. This has been the main criticism of the older generation sunscreens. This undesirable visual effect has been addressed by reducing them to the size of nanoparticles. When used in this form, these oxides cannot be seen on the skin, but they still retain their UV-blocking properties.
Source: Antaria Nanotechnologies http://www.antaria.com/irm/content/nanotechnology.aspx
Why the hype about nanoparticles?
Similar to the hype on Facebook about spray-on sunscreens, there has been concern that nanoparticles in sunscreens can be absorbed into the circulation causing cancer.
How safe are sunscreens?
The available evidence suggests that sunscreens have an excellent safety profile and are without significant absorption. This website by the Australian Government Therapeutic Goods Administration (TGA) concluded that titanium dioxide and zinc oxide nanoparticles do not penetrate the underlying layers of skin, with penetration limited to the stratum corneum (outermost layer of the skin), and neither of them is likely to cause harm when used in sunscreens. I highly encourage a read:
Are there any downsides to sunscreen?
Yes. Some individuals are allergic to sunscreen This ranges from mild to severe. Most of the UV filters known to be contact sensitizers such as para-aminobenzoic acid (PABA), amyl-dimethyl-PABA, or benzophenone-10 are now rarely used in sunscreen manufacture. Oxybenzone (benzophenone-3), is the most frequent cause of sunscreen-induced photoallergic contact dermatitis. However, the estimated rate of contact sensitization to oxybenzone-containing products is <0.1 percent to 1.0 percent.
Some UV filters (eg, octinoxate, oxybenzone) have been found to have estrogenic effects in animal models. In one study, oral oxybenzone induced an uterotrophic effect in immature rats. However, when studied in humans, there is no evidence that sunscreens alter the sex hormones in humans.
How to spot fake news?
Whilst I have done my best to present scientific data, this fake news of ?sunscreens causing cancer? will be one of a million other fake news yet to come. A while ago when news was delivered in print, authors had to think long and hard before publishing news as print was expensive.
Here are some tips on spotting fake news:
Author: Dr. Eugene Tan, MBChB, FACD, FRACP, FACMS
Skin blog 5 - November 2016 - Sunscreens, open water swimming and being sunsmart
Did you know that ultraviolet radiation is a Class I carcinogen (cancer causing agent)? This means that it is in the same category as a nuclear bomb explosion, arsenic and asbestos. Yes, the sun that creates all life on planet earth, is also the biggest cancer causing agent. So what can one do to prevent skin cancer? You simply have to be sun-smart. Felt like you?ve heard this before? Read on:
The low-down on sunscreens
Sunscreens are really the key to prevention of skin cancer and sun damage. However, studies have shown that the compliance to sunscreen advice is about 4.4%. This means that out of one hundred people that I provide sunscreen advice, only four would use it properly.
A sunscreen's SPF (Sun protection Factor) measures the ability of the sunscreen to protect against sunburn. For example, an SPF 15 means that 1/15th of the burning radiation will reach the skin, assuming an application of 2 milligrams per square centimetre (mg/cm2).
This is what 2mg/cm2 looks like:
It is the equivalent of ¼ teaspoon to cover the area of your face. Any amount less than this will reduce the effectiveness of the sunscreen.
Unfortunately, there has been recent trends for overzealous marketing towards higher digit SPFs to promote the sale of the sunscreen. Merely applying sunscreen is not a guarantee against skin cancer. Application amount (as above), application technique, water resistance and type of sunscreen are all important.
The water resistance of sunscreen is always measured under artificial, experimental conditions. This means that human skin (with sunscreen) has been submerged in a temperature regulated water tank and subject to various water agitation and then having its SPF re-measured.
For open water swimmers, the practical application of this artificial simulation is limited. We swim at varying water temperatures, against current, our skin moves as we perform each stroke; hence the actual/real-life water resistance of sunscreen is much less.
The average user of sunscreen applies sunscreen so thinly; it achieves only 20-50% of its effectiveness. In addition to applying the right amount as detailed above, application technique is also important as areas that are commonly missed are ears, back of hands, neck, feet and legs. In addition, sunscreens are often applied non-uniformly, resulting in some sites achieving little or no protection.
Sunscreen should be applied 15-20 minutes before going out and then re-applied 15-20mins after sun exposure begins and then every 2-3 hours thereafter. The best sunscreen is only as good as the user.
Choosing the right sunscreen
A good sunscreen will have protection against both Ultraviolet B and Ultraviolet A rays so do not be fixated on just the SPF. Sunscreens are divided into two categories: physical blocks (eg. Zinc oxide, Titianium oxide) and chemical blocks (Eg. Parsol MCX, Oxybenzone). Most sunscreens have a combination of both. However, some individuals may be allergic to chemical blocks and therefore have to use only physical block sunscreens.
The sunscreen paradox
Sunscreen use has paradoxically been associated with increasing incidence of skin cancer.
Why? Sunscreen use failure. There is a sense of ?immortality? when using sunscreens. Studies have shown that using sunscreens with high SPF has been associated with longer duration of sun exposure than sunscreens with a lower SPF.
Application of sunscreen is just one measure for controlling sun exposure. Seeking shade around mid-day, wearing clothes and wide-brimmed hats are also important.
Dr. Eugene Tan is an open water swimmer, Ironman triathlete and Dermatologist/ Mohs micrographic surgeon. He swims all year round with the Bay Open Water swimmers and the Williamstown Mussels. He has a passion for open water swimming and will be completing the RIP swim and the Alcatraz swim.
Skin blog 4 ? November 2015 Can a Vitamin prevent skin cancer?
Non-melanoma skin cancers, such as basal-cell carcinoma and squamous-cell carcinoma, are common cancers that are caused principally by ultraviolet (UV) radiation.
In a recent study, published in the New England Journal of Medicine, Nicotinamide (vitamin B3*) has been shown to have protective effects against damage caused by UV radiation and to reduce the rate of actinic keratosis (sun damage). *Vitamin B3 is present in most multi-vitamin supplements.
The investigators studied 386 participants who had had at least two non-melanoma skin cancers in the previous 5 years. They were randomly allocated to receive 500 mg of nicotinamide twice daily or placebo for 12 months. Participants were evaluated by dermatologists at 3-month intervals for 18 months.
At 12 months, the rate of new non-melanoma skin cancers was lower by 23% along with a reduction in 11% of actinic keratosis (sun damage).
What does this mean for me?
The results from the study are promising. It must be borne in mind that this is one of the first study of its kind, follow up is relatively short (18 months) and only 386 participants was studied. In spite of these limitations, this study is exciting.
Whilst a definite cure or prevention of 100% of skin cancer is not yet available, there is promise that for something as simple as taking Vitamin B may be useful.
Andrew C. Chen, M.B., B.S., Andrew J. Martin, Ph.D., Bonita Choy, M.Med., Pablo Fernández-Peñas, Ph.D., Robyn A. Dalziell, Ph.D., Catriona A. McKenzie, M.B., B.S., Richard A. Scolyer, M.D., Haryana M. Dhillon, Ph.D., Janette L. Vardy, M.D., Anne Kricker, Ph.D., Gayathri St. George, M.Sc.Med., Niranthari Chinniah, M.B., B.S., Gary M. Halliday, D.Sc., and Diona L. Damian, Ph.D. A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention N Engl J Med 2015; 373:1618-1626
Skin Blog 3 ? October 2015
The PBS funds new ?revolutionary drug? for psoriasis ? Am I eligible?
As of 1st October 2015, the PBS (Pharmaceutical Benefits Schedule) now funds a new medication Cosentyx (Secukinumab) for the treatment of psoriasis. http://medianet.multimediarelease.com.au/bundles/d7083e90-46e9-442b-9299-fb9b59ba81fa
The most common question that dermatologists gets asked is, ?Can I be on the drug??.
Psoriasis is a common skin problem that affects up to 6.6% (or 1.6 million) Australians. Of those individuals, 1% will have psoriasis that is severe enough that treatment is needed as it affects quality of life.
Treatment for psoriasis is chosen based on severity, patient preference, effectiveness and assessment of response. As a dermatologist, the safety of any medication is paramount and must be balanced by risks of under-treatment.
The four broad categories of treatment (chosen in order of severity and side effects) are:
The PBS imposes criteria for eligibility of biologic therapy. These are:
Cosentyx® is a human IgG1 monoclonal antibody that selectively binds to the interleukin-17A (IL-17A) cytokine (protein that is secreted by cells that carry signals to neighbouring cells) and inhibits its interaction with the IL-17 receptor. IL-17A is a naturally occurring cytokine involved in normal inflammatory and immune responses. Cosentyx® inhibits the release of proinflammatory cytokines and chemokines that are important in the development of psoriasis.
Cosentyx® along with other biologics, carry risks/ side effects. Cosentyx® may increase the risk of infections. A higher rate of infections was observed with secukinumab treatment in clinical trials, and these may be life-threatening.
It is administered by injection (subcutaneously), 300 mg once weekly at weeks 0, 1, 2, 3, and 4 followed by 300 mg every 4 weeks. Some patients may only require 150 mg per dose.
Your dermatologist would be the best person to discuss psoriasis treatment with you. Whilst, the appeal of a new drug is apparent, patients must fulfil PBS criteria to be eligible for funding of this medication. No medication is without side effects. If you think you may be eligible for Cosentyx®, discuss this with your General Practitioner and a referral to a Dermatologist may be warranted.
Skin Blog 2 - August 2015
Winter and Your Skin
The words ?winter? and ?dry skin? are often considered synonymous. Did you know that dryness of the skin has almost nothing to do with the amount of water you drink? Dryness of the skin (xerosis) is actually related to changes in the protein and lipid content of the stratum corneum (uppermost layer of the skin). This change in the stratum corneum alters the scattering and reflection of light leading to a dull, rough appearance to the skin. Skin dryness can be triggered by changes in the environment or due to factors related to your overall health. In winter, the most common cause is a change in the humidity of the environment.
Winter brings about three common problems in the skin: dry skin, worsening of eczema and skin cancer. The stratum corneum plays an important role in the barrier function of the skin and when skin becomes dry, its barrier function is affected and this can exacerbate eczema. A good moisturizer is an important part of winter-skin-care and those that contain glycolic acid will improve the skin?s appearance and texture.
Skin cancer does not respect seasons. Research has shown that melanomas are thicker and diagnosed at a later stage in winter than in summer. This is most likely due to an increased awareness of skin cancer in summer when compared to winter. Hence winter is not a time to be complacent. Your dermatologist is the best person to discuss skin checks and skin care.
Dr. Eugene Tan, MBChB, FACD, FRACP, ACMS
Dermatologist and Fellowship Trained Skin Cancer & Reconstructive Surgeon
Blog 1 July/2015
Keytruda® (Pembrolizumab) - New treatment for Melanoma.
What does this mean and how does it apply to me?
Last week, the Australian Government approved funding of Keytruda® to treat melanoma:
Malignant melanoma is a serious type of skin cancer due to uncontrolled growth of pigment cells (melanocytes). Australia and New Zealand have the highest incidence of melanoma in the world. Despite sun protection messages over the last 30 years, melanoma incidence has increased more rapidly than for any other cancer.
In most cases, melanoma arises from otherwise normal appearing skin (75% of cases) but a melanoma can also occur in a precursor lesion such as a normal mole (benign melanocytic naevus) , afunny-looking mole (atypical naevus) or a birthmark (congenital melanocytic naevus).
Melanoma is staged depending on how thick it is and whether or not it has spread from its original site. The thicker the melanoma, the more advanced the stage and the poorer the survival.
Keytruda® is also known by its drug name, Pembrolizumab. When a malignant melanoma develops, it can express certain proteins on its surface such as PDL-1 which helps it evade or hide from the immune system. This means the melanoma will remain undetected from the immune system. PDL-1 on the melanoma binds to specific proteins (PD-1 and B7.1) on T-cells (an important cell in our immune system) and disrupts their ability to detect the melanoma.
Pembrolizumab is an antibody against PD-1. By blocking this protein on the T-cell, it returns the T-cell to its active state allowing it to detect the melanoma and destroy it. Therapy with Keytruda® improves overall survival in patients with advanced melanoma (6-month progression-free-survival rates of 47.3% for pembrolizumab every 2 weeks, 46.4% for pembrolizumab every 3 weeks, and 26.5% for ipilimumab and 12-month survival rates were 74.1%, 68.4%, and 58.2%, respectively). The drug is given by intravenous infusion every 3 weeks for as long as it is working.
How does this affect me? Keytruda® is licensed for use in advanced, metastatic melanoma. This is also known as Stage IV disease or melanoma that has spread beyond its initial site at the skin to the rest of the body. Keytruda® is not for use in healthy individuals for prevention of melanoma, nor is it licensed for use in earlier stages of melanoma. If you have advanced, metastatic melanoma you may want to discuss your case with your cancer specialist, Oncologist on whether or not Keytruda® may be of benefit to you.
For most cases of melanoma, diagnosis is made at an early stage and surgical excision is curative. A skin check by a dermatologist can greatly assist in detecting melanoma at an early stage.
Written by: Dr. Eugene Tan MBChB, FACD, FRACP, FNZDS, ACMS