Testing

The following tests maybe used in a dermatology clinic, however, this is just a summary of some of the common tests used, there may be others. If you have any questions about tests you are being asked to take, don’t hesitate to ask questions about it.

Examination of affected area:
The staple of dermatology practice is the skin examination. Alongside your explanations and medical notes this will help your doctor or nurse make their initial assessment. Although it is natural, try not to feel self-conscious, your doctor or nurse will have seen it all before.

Dermatoscopy:
A dermatoscope, sometimes called a dermascope, is a device which magnifies and illuminates the skin, allowing doctors to closely examine the skin. Although it can be used to diagnose a range of skin conditions, it is most commonly used when examining potential skin cancers.

Dermatoscopes show doctors details under the skin which aren’t visible to the naked eye. When combined with digital photography this can give incredibly detailed records of the skin, particularly skin lesions such as moles, making it easier for future changes to be spotted.

Skin scrapings and swabs
Sometimes it is necessary for dermatology patients to provide samples to aid with diagnosis. This is often done using either skin scrapings or swabs. Swabs use a tool, similar to a cotton bud, to gather a sample. Skin scrapings usually use a scalpel, a type of knife, gently brushed across the skin, like you would a razor blade, to carefully remove a small sample of skin cells for testing. Depending on the site this may require the removal of the surrounding hair.

Other skin biopsies
A skin biopsy is a procedure which involves removing a small section of the affected skin for testing, to aid in diagnosis. This is commonly used to test potential skin cancers, amongst other things. They are considered minor surgeries.

The three main types of biopsy are:

Punch biopsies: This biopsy uses a circular punch blade to take a small sample of skin. The benefit of a punch biopsy is that the sample, while small, includes deeper layers of skin.

Shave biopsies: This type of biopsy uses a sharp tool to remove a small part of the top layers of the affected skin.

Excisional biopsies: This type of biopsy involves the removal of the entire affected area with a scalpel, for example a mole, which is then tested.

To find out more about biopsies and how long they take, head over to our blog post on this subject. 

Patch tests
Patch tests are specialist procedures carried out by dermatology doctors and dermatology nurses to find out whether your skin condition is caused or aggravated by an allergy to substances which have come into contact with your skin. This is called contact allergy.

Patch tests involve three visits to a specialist. Each substance to be tested will be applied to your back in special small disc (about 1cmin diameter) containers held in place by hypoallergenic tape. The location of the containers is identified by marking your back with ink. Occasionally the arms or the thighs are also used to patch test. Itching of the test areas is normal, but you are strongly advised not to scratch. You should allow up to 2 hours for this first visit.

The substances will remain taped in place until your next visit, when the taping is removed, and any reactions noted. Additional patches are sometimes added at this stage. The marking ink and/or tape will remain on your back for a further two days. On the third visit, your back will be examined,and any reactions will be discussed with you. It may be necessary to expose part of your arm or back to ultraviolet light if a reaction to sunlight is suspected. This is called ‘photopatch testing’.

Questionnaires
It isn’t uncommon for doctors to ask you to fill out a questionnaire to get an insight into your condition, its severity, and even things such as its impact on your day-to-day life and mental health. Common questionnaires include the Dermatology Life Quality Index (DLQI)and thePsoriasis Area and Severity Index (PASI). These are a good way to get a lot of relevant information quickly, and can often be done whilst you are waiting, ensuring you get the most out of your consultation.