The Kirby-Desai Scale for Laser Tattoo Removal

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Anyone in the laser tattoo removal field has heard at least one of the following questions. “How long does the tattoo removal process take?” or “How many sessions will I need in order to achieve complete removal?” If you’ve heard either of these questions, then you most definitely know that there is no definitive answer.


In fact, it is almost impossible to determine the exact number of laser treatments a patient will need. Why is this? Every patient is different and so is their tattoo. The rate at which a tattoo fades is dependent on a variety of factors that are specific to each patient.

Drs. Will Kirby and Alpesh Desai, skin specialists in tattoo removal, created a predictive scale to help quantify the number of treatments needed for a patient to achieve optimal results. Named the Kirby-Desai scale, clinics all throughout the world now utilize this practical tool to best estimate the total number of treatment sessions needed for an individual patient.

This article will delve into Drs. Kirby and Desai’s research and how their scale may be implemented in your practice.



What is the Kirby-Desai Scale?

The Kirby-Desai scale is a quantitative system that assigns numerical points to six different factors that, when summed together, reveal a score that determines the number of treatments a patient will need for successful removal. The six factors and their point systems are as follows:

Patient Skin Type: 1 to 6

Laser tattoo removal can be successful across all patient skin types. However, patients with darker skin tones and more melanin are more susceptible to experiencing pigmentation changes likes a lightening or darkening of the skin. For this reason, laser practitioners revert to safer treatment protocols such as lower energy laser settings and longer waiting periods between treatment sessions to minimize the risks of unwanted side effects. According to the Kirby-Desai scale, lighter skin types need fewer sessions.

Location of Tattoo: 1 to 5

Once a laser shatters the ink trapped in the dermal layer, the ink pigments are flushed out by the body’s immune system, specifically the blood and lymphatic system. Thus, tattoos placed closer to the heart and major blood vessels fade at a faster rate. According to the Kirby-Desai scale, tattoos on the head, neck, and upper body need fewer treatments than outer regions of the body such as the feet and hands.

Color(s) of Ink: 1 to 4

Each color used in a tattoo requires a specific wavelength of light to be removed. Some tattoo colors are considered easier to remove than others. Black is known to be the easiest color to treat as it absorbs all wavelengths. Second to black is red, when compared to other colors. Green, yellow, and blue are considered some of the most difficult to treat, thus receiving a higher point on the Kirby-Desai scale.

Amount of Ink: 1 to 4

There are two types of tattoo applications – amateur and professional. Amateur tattoos tend to contain less ink and have unevenly applied ink. Conversely, professional tattoos typically use more ink and place the ink deeper into the skin. In their study, Drs. Kirby and Desai found that most amateur tattoos were smaller in size in comparison to professional tattoos. They categorized the amount of ink into 4 categories: amateur, minimal, moderate, and significant, with amateur needing the fewest number of treatments.

Scarring/Tissue Change: 0 to 5

Tattoo application can sometimes lead to scarring and tissue change, depending on how aggressive the tattoo artist applied the tattoo. Tattoos that have existing scarring and tissue change are much more difficult to remove and usually require more treatment sessions. The study found that patients with darker skin types are more prone to scarring. Scoring is based on the severity of scarring or tissues change.

Layering/Cover-Ups: 0 to 2

Many patients try to remove a tattoo by covering or layering a new design over the previous unwanted tattoo. The new tattoo is usually larger in size and often uses twice the amount of ink in order to effectively conceal the preexisting tattoo. Laser tattoo removal on a cover-up tattoo will first remove the new tattoo and reveal the original tattoo. Therefore, more treatments will be needed to successfully remove the ink from the combination of cover-up tattoo and old tattoo.



About the Clinical Study

The Kirby-Desai scale was created during a clinical study that was published in 2009. The study took place over the course of 4 years, July 2004 to August 2008, on a total of 100 patients over the age of 18.

Two critical factors to note about this study:


Photosource: The Journal of Clinical and Aesthetic Dermatology

The study resulted in complete removal across all 100 patients. The number of total required treatments needed ranged from 3 to 20, with an average of 10 treatments. The histogram shown above was taken from the study and compares scores calculated by the Kirby-Desai scale prior to treatment verses the actual number of treatments performed to achieve complete removal.



How It Affects Pricing

HiRes.jpgLaser tattoo removal cost is often determined by the size of the tattoo being treated multiplied by the number of treatment sessions it will take to remove that tattoo. By implementing the Kirby-Desai scale, laser practitioners are able to provide a more precise estimate of how many treatments are required. The keyword being estimate, as the Kirby-Desai scale is only 80% precise. 

As we mentioned at the beginning of this article, there is no definitive answer as to how many treatments a patient will need for complete removal. The Kirby-Desai scale allows laser practitioners to accurately predict the number of treatments needed, however the number produced by this scale should not serve as a conclusive answer. 

By determining the number of sessions needed, combined with the size of the tattoo being treated, patients are able to more accurately plan for the total amount they will be spending to have their tattoo removed.



Ultimately, laser tattoo removal is unique to each patient and tattoo. Various factors come into play when determining the number of treatments a patient will need before seeing clear, inkless results.

The Kirby-Desai scale has proven to be very helpful in laser tattoo removal practices all over the world – especially for patients – as it allows them to budget and prepare for the removal process before making a commitment. 

Although there is no resource that precisely determines the exact number of treatments needed for complete removal, the Kirby-Desai scale provides the closest prediction to the real number of required laser tattoo removal sessions.

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