"What's this doc?" - Using Punch Biopsy to Diagnose Skin Cancer | What to Expect?

"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.

Sutured

• 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.

Before You Start Those Antibiotics! (Part 1) | Harmful or Helpful?

What is your reaction when you are prescribed antibiotics?

Some patients outright reject antibiotics, while others outright demand antibiotics. Perhaps you are somewhere in between, or would rather defer to whatever the doctor recommends without second thought?

Whether you have strong opinions or none, I believe it is important to think critically about any medication being prescribed by discussing good quality evidence with your treating doctor. What better place to start than one of the commonly prescribed medications: antibiotics!

Benefit and Harm

The advent of antibiotics in the early 20th century sparked a new revolution in medicine, saving countless lives and preventing complications from what are now easily treatable diseases.

Simple Tonsillitis?

One relevant example is something as common as tonsillitis which can create misery with terrible throat pain and fevers. The actual tonsil infection is usually not a significant issue, as most healthy people can overcome the immediate infection naturally without antibiotics.

However, in a small number of people, if streptococcus bacteria has caused tonsillitis, it can create a reaction in the body many weeks down the track, which can result in long-term issues with the heart (rheumatic fever) or kidneys (post-streptococcal glomerulonephritis).

These serious complications are much more common in remote communities where poor access to healthcare means simple tonsillitis is often left untreated. We are so privileged in Sydney to have easy access to antibiotics for the treatment of common bacterial infections.

Antibiotic Misuse

Conversely, the overuse and misuse of antibiotics particularly in third-world countries have created terrifying antibiotic resistant organisms. In the community, there is also increasing awareness of antibiotic side effects and their harms on the body. Antibiotics, particularly those that are more broad-spectrum, act indiscriminately to kill usual resident bacteria in the body, causing issues such as bowel related side effects or thrush.

There is a great push in the medical community, particularly among infectious disease physicians, to promote proper antimicrobial stewardship: which is a fancy way of saying to their medical colleagues, "Don't misuse or overuse antibiotics!"

Therefore, in every case of antibiotic prescribing, we must first be very clear about:

• How likely is the illness is caused by a bacteria?

• How impactful are antibiotics on the natural course of an illness?

In a future post, we will explore these questions further and discuss the factors which guide our decision-making.

Broader Reading: Beyond the Basics

It's not just non-medical communities who are saying the use of antibiotics should be more cautious. This government website explains what it means to use antibiotics in a responsible manner. Particularly relevant is the section on 'Patient resources' which lists many helpful links for you to delve deeper into the topic.

Lost in Communication: What did the doctor say again? | What makes an effective consultation?

Being a GP, it's inevitable having friends approach me for a medical opinion. Recently a pregnant friend who typically has bad allergies was told in no uncertain terms by her GP not to take antihistamines because they are bad for the baby. Another part of the proposed solution was to get rid of their cat by asking someone to look after the poor fur ball until after she gives birth.

To no-one's surprise, the idea of cat abandonment was outright rejected. She did try to stop the unsafe antihistamines, but ended up taking some once or twice a week anyway because the symptoms were unbearable. Weeks later when the midwife told her that some antihistamines were actually suitable in pregnancy, my friend approach me about her situation.

Our beloved munchkin cat, Luna, in her days of kittenhood.

Paternalism: Here's What You Gotta Do

My goal here is not to judge the actions of another GP nor criticise their management of allergic rhinitis in pregnancy. I do however see a constructive learning point we can generalise from my friend's experience.

When GPs are under extreme time pressure, more often in bulk-billed settings, it is easy to see an issue (unsafe antihistamines in pregnancy), present a solution (avoid use of antihistamines and get rid of the cat) then send patients on their way leaving them the responsibility to comply. All doctors including myself have all been guilty of this at some point.

In fact, this actually happens all the time:

• "Your cholesterol is very high, you are going to do some exercise and change your diet for the next six months. Then we will repeat the blood test."

• "It's just a virus, so we shouldn't give antibiotics for your cold. Come back in a few days if you feel worse."

• "Your back pain is just mechanical, which means it should get better within six weeks. Go to the physiotherapist, and if it doesn't get better by then, come back and we can do a scan."

All these scenarios are very reasonable, and the clinical advice may indeed be appropriate and evidence-based. The patient leaves with the impression that they should do what the doctor has told them.

So what are we missing here?

Compliance vs. Collaboration

Traditionally, whether patients follow through on what the doctor does is a matter of compliance, doing what they are told. Any disobedience means the patient is non-compliant, as though all fault lies with the patient in their lack of adhering to advice.

The more modern approach is a patient-centred collaboration which asks a few important questions:

• What is the patient's understanding of the problem? How can doctors effectively convey information with clarity to help patients understand relevant issues?

• How can patients be brought into decision-making about their health? What are critical pieces of information to help patients make such decisions?

• What is the patient's view on proposed management options? What are some potential barriers or concerns and how can they be addressed?

• How can the doctor work with the patient to implement the management plan in a manner that is relevant, practical and personalised for them?

My personal emphasis in the patient-centred approach.

Collaboration: A Patient-Centred Approach

For my friend, if removing the allergen (cat) wasn't an option and the severity of her condition was such that she cannot go without anti-histamines, the plan was doomed for failure from the start. It may have made a difference if there was an opportunity to discuss these potential barriers and negotiate a different individualised solution.

Likewise, for the scenarios listed above:

• How long has the cholesterol been high and what measures have the patient tried in the past? Why have past measures failed? What are realistic goals the patient can suggest and agree to implement?

• What is the patient's view on their cold? What were their concerns and expectations going into the consultation? If they are worried and wanting antibiotics, how can this be negotiated?

• How does the back pain impact the patient's work? What are some potential psychological impacts from having back pain (such as being unable to pick up kids or do certain hobbies)? Perhaps a tighter follow up schedule is required to check in on the patient to provide further support and other management options as appropriate?

This approach translates to an often very time-consuming consultation. It is much easier and quicker to provide the correct solution and move on to the next patient. While cookie-cutter management may appear medically sound for the diagnosed condition, they may not be effective for the patient.

Exploring potential issues, discussing different viewpoints and options, then negotiating a plan can easily double the time of a consultation which most GPs do not have. Yet how effective we are as GPs are often determined by the extent by which we achieve collaboration, and ensure the patient is well understood through the discussion and implementation of a personalised management plan.

Why Blood Pressure?

I started my blog with simple articles on blood pressure. While the information is straight forward, my emphasis for patients to measure their own blood pressure is the very concept of collaboration.

Measuring blood pressure at home is never something I push onto patients, but I extend it as an opportunity to do something proactive about their cardiovascular health. It is a relatively easy task which patients cannot really fail, building their confidence. Finally, having a machine at home produces a sense of ownership about their health by providing the ability for opportunistic monitoring, improving health awareness.

In every consultation, GPs have a choice to promote cooperation and routinely bring patients into decision-making. Next time you go to the doctors, reflect on whether the plan is something you've been told to do, or if it's a personalised plan you have negotiated with your doctor which takes into account your concerns and needs. Every consult is an opportunity for you to take part in managing your health!

Broader Reading: Beyond the Basics

• Patient-centred health is a broad topic, covered by numerous health bodies ranging from NSW Health to overseas institutions. This NHS booklet from the UK is an excellent read for patients to learn what constitutes patient-centred care.

• Likewise, the Victorian government has a great summary on the key points of patient-centred care.

• What does the patient-centred approach look like for children in the context of involving the family? The Sydney Children's Hospital Network provides an interesting overview of this.

• Related to patient-centred care is the notion of patient engagement. The WHO has a document which provides insights for patient engagement in the primary care setting.