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Skin biopsy


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A skin biopsy is a routine investigation that helps us to diagnose skin conditions.

A biopsy is where a small sample of skin is removed so it can be looked at under the microscope to make a diagnosis.

It can also be used as a treatment to remove some abnormalities, such as moles.

You will be given local anaesthetic. This is a medicine that numbs the specific area of the body so it is pain free, but does not put you to sleep.

Before your biopsy

If you are planning to travel within 2 weeks after your biopsy, please let us know as this will affect arrangements for removing your stitches (if you have them).

Some people feel light-headed after their biopsy. You must not drive to your appointment, and should have someone to accompany you home. You can eat and drink as normal before your appointment.

Medicines you take

We need to know if you are taking certain medicines, as they can increase the risks of bleeding and bruising. Please let the staff looking after you know if you are taking any

  • antiplatelet medicines (such as aspirin or clopidogrel)
  • anticoagulant medicines (such as warfarin or rivaroxaban)

Please do not stop taking any of these medicines. 

If you are taking warfarin, please visit your local warfarin clinic 2 to 3 days before your surgery date and have your INR checked.

If your INR is below 2 or above 3.5, contact the dermatology clinic.

We might need to rearrange your biopsy date.

If you have any allergies to medicines including local anaesthetic, please let us know.

During your skin biopsy

The biopsy will be performed by a doctor or specialist nurse.

We will give an injection of local anaesthetic to the area where the biopsy will be taken. This may sting for a few seconds, but then the area will be numb.

You might feel pulling or pressure on the area when we take the biopsy, but it should not be painful.

We will take a sample of tissue by cutting or scraping your skin.

We might have to take more than one biopsy, depending on your circumstances.

If we close your wound with stitches, you will need to have these removed at your GP surgery.

The whole procedure is usually completed within 30 minutes.

After the procedure

A nurse will dress your wound and explain how to look after it at home.

You should be given aftercare information before you leave hospital.

If you have stitches, your nurse will also talk to you about arrangements for getting them removed, and will give you a letter to give to the nurse at your GP practice.

You will be able to leave hospital as soon as you feel well enough, and can eat and drink as soon as you wish.

Painkillers for any pain or discomfort

The local anaesthetic will begin to wear off about 30 to 40 minutes after the operation.

If you have any discomfort from your wound, you can take simple painkillers such as paracetamol to help with this.

Always follow the instructions on the packet and never take more than the recommended dose.

Check that the painkillers will not react with any other medicines you are taking.

If you are unsure or if you have allergies to any medicines, speak to your pharmacist.

Giving your permission (consent)

We want to involve you in decisions about your care and treatment.

If you decide to go ahead, you will be asked to sign a consent form. This states that you agree to have the treatment and you understand what it involves.

There are no alternatives to this procedure. It is the only way to get the information needed to make a correct diagnosis.

If you would like more information about our consent process, please speak to a member of staff caring for you.

Risks of biopsy

We will discuss the risks with you in detail before we ask you to sign the consent form.

Short term risks include infection, bleeding and swelling of your wound. Although the biopsies taken are not large, you will have a small scar.

Follow-up appointments

We will arrange a follow-up appointment, where the results of your biopsy will be discussed with you.

Contact us

If you have any questions or concerns about your biopsy, please contact Guy’s Dermatology Outpatient Department.

Call 020 7188 6418, Monday to Friday, 9am to 5pm. 

The Dermatological Surgery and Laser Unit (DSLU) offers an answer phone service.

Call 020 7188 6284, Monday to Friday, 9am to 5pm. Please leave a message with your name and telephone number and someone will get back to you as soon as possible.

In an emergency, please contact your GP or go to your nearest Emergency Department (A&E).


Ref number: 1680/VER10

Last reviewed: January 2019 | Next review: January 2022

A list of sources is available on request


Where next?

 Contact us

Guy’s Dermatology Outpatient Department

Phone 020 7188 6418 Monday to Friday, 9am to 5pm.

The Dermatological Surgery and Laser Unit (DSLU)

Phone 020 7188 6284
Monday to Friday, 9am to 5pm.

Please leave a message with your name and telephone number.

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