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Doctor Lin Answers

As we start 2022, summer is already in full swing in Australia. The ongoing pandemic and surging Covid cases only mean more people are spending time on a beach in the sun than enjoying the comforts of air conditioned amenities. This is also the time when many patients are more aware of their skin and come for skin checks. In fact, many skin cancers we diagnose are found and first noticed by the patient, highlighting the importance of performing self skin checks.

Why are Self Skin Checks so Important?

Compared to other countries in the world, Australia has the highest incidence of skin cancer by a wide margin. While the public message of being sun smart has been effective in more recent years, many were still exposed to excess sun in the days of their youth.

Despite being written a while ago, this 2012 article in the Australian Family Physician provides a general guide regarding frequency of self-examination (see Table 1).

  • High risk: 3 monthly self-examination

  • Medium risk: 3-6 monthly self-examination

  • Low risk: Annual self-examination

You are typically higher risk if you have:

  • Fair skin type (particularly red hair, blue/green eyes, freckles).

  • Numerous moles (numbering in the dozens)

  • Past history or family history of skin cancers, especially melanoma

  • Previous (particularly numerous) sunburns

Where do I Check?

It is important to have a comprehensive check through your whole body. Places that people often miss include:

  • Back - Use a full-length mirror or get a partner to check

  • Behind the ears

  • Scalp - Sometimes your hairdresser may comment on a particular spot.

  • In between toes and underneath your feet

The American Academy of Dermatology has a brief guide on self-skin checks, including this short video embedded below.

What do I Look for?

As a start, the ABCDE rule for melanomas should be applied to any mole on your body. This is helpfully outlined by the Melanoma Institute of Australia, summarised in the image below.

The last point is perhaps the most important, relating to evolution. Anything changing could be suspicious, in particular: recurrent crusting, bleeding, change in colour or size.

Other helpful clues include:

  • Ugly duckling sign: Out of a group of similar spots, anything that is becoming cancerous will often stand out

  • Non-healing scab: Crusts which keep forming and falling off without healing

  • Non-healing wounds: A longstanding wound that isn't getting better after weeks

  • Fast growing lump: A firm lump that is growing quickly over weeks should be treated with caution

Learning about Skin Cancers

Sometimes a patient comes to me with significant concerns about a spot, yet it is something clearly benign. While another patient may be requesting a routine check, only for me to find some pre-cancerous or even cancerous change.

In either case, I don't simply say whether something is cancer or not. It is important for me to explain what the spot is and also outline the reasoning for my clinical opinion. Since there is so much to know about skin cancers, in my approach I see every skin check as an opportunity to further equip and educate patients so that they become more effective at monitoring their own skin and looking out for cancers.

If you're ever not sure about a spot, or want to learn more about skin cancers, don't hesitate to visit your local doctor with an interest in skin cancer medicine. We are sure to listen and help!

Broader Reading: Beyond the Basics

While there are many types of skin cancers, patients who seek to know more about specifics can have a browse of DermNet NZ, an excellent and reputable source of information. Topics are written in a manner that can be understandable to patients with technical words underlined with pop-up definitions to help overcome jargon. You may choose to begin with reading about the main three types of skin cancers:

In a previous article, we discussed the importance for patients to think critically when prescribed medications. Starting with antibiotics, there are certainly great benefits but also some harms. How do we go about making a decision on whether to use antibiotics?

Is it Cause by Bacteria?

One difficulty in knowing when to prescribe antibiotics is due to the fact that the same condition can be caused by both viruses and bacteria. In many cases it can be difficult to distinguish between the two.

For example, the colour of phlegm was commonly used to aid the decision on whether a cough is bacterial. However, apart from maybe those with specific chronic lung disease or long-term cough, coloured phlegm cannot reliably predict whether illness is caused by bacterial infection.

GPs who care about appropriate use of antibiotics are excellent at distinguishing between viral or bacterial disease. This comes from observing clinical features which are more likely in bacterial or severe infection, allowing for appropriate early antibiotics. As well as having experience in treating a large number of patients and safely managing the majority without antibiotics.

If you are ever unsure about taking antibiotics, don't simply take the script and mull over the decision at home. Feel free to ask your GP about the factors which compelled them to prescribe, in addition to any other questions or concerns you may have.

Will it Make a Difference?

For some patients, there is the perception that antibiotics will definitely help regardless, such that there's no harm in taking it anyway. In contrast, the Australian Commission on Safety and Quality in Health Care provides interesting fact sheets which highlight the true difference antibiotics make in some cases.

Example 1: Middle ear infections typically last around 84 hours. Children who take antibiotics typically have earache for only 12 hours less than children who don't take antibiotics.

Example 2: In typical cases of acute cough which lasts an average of 7 days, those who take antibiotics have the cough 12 hours less than those who don't take antibiotics.

There is another fact sheet for sore throat (acute pharyngitis) as well.

The reason these numbers indicate antibiotics don't make much of a difference is not because antibiotics are ineffective, but rather that the majority of patients with these conditions have viral rather than bacterial infections.

It is still important to attend your GP early as it is their role to decide whether antibiotics will truly make a difference. Early antibiotic treatment will often be required in cases of severe disease or patients with certain co-morbidities.

Why Not Take Antibiotics Anyway?

At this stage you may be asking, "If antibiotics could help a bit anyway, why don't we take them regardless? 12 hours less is still a benefit."

This is where we have to take side effects into account. No treatment is without potential harms.

Taking the example of middle ear infections, since a majority of ear infections are self-limiting anyway, they would get better even without antibiotics. While 5 children out of 100 might get better sooner on antibiotics, 7 children out of 100 will get some side effect from antibiotics.

In other words, more children are harmed than helped! This is one of the reasons we always weigh benefits and risks carefully before deciding if and when to give antibiotics.

Past Experience of Harm

Perhaps you appreciate these facts and figures apply to the average patient, but you've had an experience where the doctor advised your child to wait and your child got so sick they had to go to hospital where antibiotics were given anyway. As a result, you have been very cautious to make sure your child receives antibiotics early to prevent that from ever happening again.

Or it seems like you or your child always crash hard when sick and you feel routine early antibiotics will prevent a devastating infection.

I truly empathise with patients or parents who have these concerns. Rest assured that GPs who have time to listen and understand your concerns will aim to individualise their management by taking unique patient factors into account. There are certainly valid reasons to give early antibiotics based on certain clues on history and examination. Meanwhile, there are also cases, particularly in mild disease, where it could be more appropriate to hold off.


There are many opinions, beliefs and experiences that colour our perception of the right approach, whether that be something as common as whether to give antibiotics, or perhaps a bigger medical decision.

Where there are questions or differences in opinion, I always see this as further opportunities for engagement and education. So next time you're given a script (or not given a script) and you're not fully certain, make sure to share your concerns.

Patient curiosity and openness to engage is so important. Our duty as GPs is to provide a listening ear to discuss your perspectives and ensure all your questions are answered.

"What's this doc?" the patient asks, edging closer with their show and tell opportunity as the skin feature comes into my view.

This is a very common question I get numerous times a week during skin checks as patients recount their carefree and youthful days of sunburnt bliss. Especially for my older patients, ignorance of sun protection in their early years seemed universal, save for some zinc on the nose.

When we suspect a skin feature of being a cancer, sometimes the next appropriate step is to take a sample of this skin which can be sent to the laboratory and examined under a microscope. How do we begin going about this?

What is a Punch Biopsy?

In the mid-20th century, scientists started drilling ice cores from Antarctica to learn about past climate by analysing layers in the sample. The skin is likewise made of many different layers which may be affected by a potential cancer. The punch biopsy tool is a circular blade which is rotated with downward pressure to create a core of tissue, sampling all the skin layers in a column.

The procedure involves:

  • Cleaning the skin surface with an antiseptic such as iodine

  • Injection of local anaesthetic with a fine needle which can cause a stinging sensation.

  • The punch biopsy tool is used, allowing a sample to be taken using a pair of forceps and scalpel/scissors.

  • Bleeding is stopped with either firm pressure alone, or the use of sutures.

  • The sample is placed in a specimen jar and sent to the laboratory for analysis.

For those who are keen to see how this looks in practice, the following video from an Australian GP college (ACRRM) provides an overview of the procedure.

Things to Know Before the Biopsy

General risks of a punch biopsy are typical of most procedures that involve cutting the skin, including, but not limited to:

  • Pain: Usually tolerable and can be managed simply after the procedure with paracetamol

  • Swelling: Initial injection of local anaesthetics can cause initial swelling. Later swelling and redness can be a sign of infection.

  • Bleeding: Typically, bleeding is stopped before you leave the surgery! It is rare but possible for bleeding to occur in the hours following the procedure, though most minor bleeding can be stopped by applying firm pressure to the wound for 15+ minutes.

  • Dehiscence (splitting open of skin surface) if sutured: Unlikely given the small diameter and lower tension of punch biopsy wounds.

  • Infection: Redness, swelling or discharge at the wound site requires review.

  • Nerve damage: Punch biopsies should be superficial and care is taken to not damage underlying nerves.

  • Adverse reaction to antiseptic, local anaesthetics or adhesive from wound dressing: Alternative products can be considered if allergic or irritant reaction is known or encountered.

  • Scarring: Possibility for scarring as a spot (if not sutured) or a line (if sutured).

How to Care for the Wound after Punch Biopsy

Various resources on this topic are available on the internet ranging from dermatology centres to professional resources. Here is my simplified summary of the after care for punch biopsy.

No sutures

  • The skin will slowly heal from bottom up, outside in. This is called healing by secondary intention.

  • Keep the wound dry for at least 24 hours, then the dressing may be changed once or twice a day.

  • The wound can be gently cleaned with soap and water then pat dry during dressing change.

  • Consider applying some petroleum jelly to the wound before covering with an adhesive bandage with non-stick gauze. Covering the wound helps with healing.


  • Keep the wound dry and covered under waterproof dressing for at least 1-2 days.

  • After removal of the waterproof dressing, the wound may be wet but not immersed with water.

  • Consider applying some petroleum jelly to promote wound healing and potentially reduce scarring. Maintaining adhesive bandage is optional.

  • Return after the agreed time period for removal of sutures.

Broader Reading: Beyond the Basics

The general principle of wound management is keeping the wound 'clean but greasy' to avoid drying it out. This is why petroleum jelly is traditionally recommended for scar minimisation of wounds.

However, there was a publicised study in 2018 showing that applying petroleum jelly too early can prevent the body from forming a natural plaster which can help wound healing. So perhaps delaying the application of petroleum jelly will achieve the best outcome.