Acne Severity Scale: How Bad Is Your Acne?

It’s when you’ve been patiently waiting but nothing seems to happen. In fact, your acne seems to get worse as time passes by.

So, you try to solve it by looking for other products you think can help make your acne disappear. And then you wait, hoping you made the right decision.

But, is it really the right decision?

Most of the time, it’s not.

One good reason is that not all people have the same acne severity level. 

For example, if you have mild acne and you’re treating it as severe, you’re just messing up with your skin.

And if you’re acne is severe and you’re not treating it with the right medications, you’re just encouraging more breakouts and wasting money.

So, how do you know if you have bad acne?

This is where this handy guide to the different acne severity scales can help you.

Go through each one to get a clearer understanding of how you should handle your acne.

But before that, let’s first discuss this.

What Are Acne Severity Scales?

Acne severity scales are exactly what you think they are. They are scales used by doctors and dermatologists to know how light or severe your acne is.

Using an acne severity scale has two goals:

  • To help determine which treatment will work best for you
  • To help assess how much your skin has improved since you started treatment

There are over 25 scales being used worldwide and surprisingly, doctors still do not agree on which scale to be used as a standard.

Meaning, the “score” you get from one place might be different from what you get from another.

acne severity scale

Though there isn’t a standardized system, all the available acne scales follow a 3-category system for inflammatory acne.

See this:

Mild - Few to several pustules/papules

Moderate - Several to many pustules/papules and a few to several nodules

Severe - Extensive or numerous pustules/papules and many nodules

Another thing is that it isn’t clear whether the existing categories only apply to face acne or it can also be used to assess acne on the back, chest or all body parts.

So, when undergoing assessment, make sure to ask your doctor how severe your acne is and which scale he’s using. This is so you know your starting point and to have an idea of how you’re going to end up.

For now, let me familiarize you with the most commonly used types of scales. This is to give you an idea of what they are, how they work, and to know what your doctor is talking about.

Different Types Of Acne Scales

Before we go directly to the different kinds of scales, let me first tell you the different ways the severity of your acne can be classified:

  • The types of lesions
  • The number of your lesions
  • Their location
  • How they affect your quality of life
  • A combination of any of these

Now, let us proceed to the different types of scales:

The Leeds Revised Acne Grading System

This scale gives scores from 0 to 10 and improvements can be measured in photos.

Created in 1998, this list is used to classify acne found on the back, chest, and face. It consists of 15 grades for facial acne (3 of which for comedonal acne) and 8 for back and chest acne.

This system, however, is a bit difficult to apply to clinical practice for two reasons:

  • The number of categories available for severe acne and the large number of subcategories in each class.
  • It does not fully explain the lightest forms of acne while the severe types are overly-represented.

The Global Acne Grading System (GAGS)

This system uses math to come up with an acne severity score. These numbers are based on the number of pilosebaceous units, their distribution, and the surface area.

First, you must assign a number (or a factor) based on where acne is located:

  • Use 1 for those on the nose and chin
  • Use 2 for those on the cheeks and forehead, and
  • plus
    Use 3 for those on the upper back and chest

Next, multiply each factor against any of these numbers based on the type of lesion in the area:

  • Use 1 for greater than or equal to one comedo
  • Use 2 for greater than or equal to one papule
  • plus
    Use 3 for greater than or equal to one pustule, and
  • plus
    Use 4 for greater than or equal to one nodule

But, like the previous one, this system has not been evaluated for reliability yet.

The Investigators’ Global Assessment Scale (IGA)

Developed by Allen and Smith Jr., this system has become the template for assessing acne severity. The full-text scale provides 5 categories and includes 9 acne grades.

This scale used to be limited to facial acne. However, it was later used to grade acne found on the back and chest as well.

acne severity scale

This system uses the following scores:

0 – Clear or normal skin (no evidence of acne)

1 – Almost clear skin (some non-inflammatory acne is present with some non-inflamed papules. Papules may be developing but are not yet pinkish-red in color)

2 – Some non-inflammatory acne can be found with a few pustules and/or papules. There are no cystic acne lesions yet.

3 – Non-inflammatory acne dominates the area and a few inflammatory lesions can be found. There may or may not be one small cystic acne lesion in the area.

4 – Non-inflammatory and inflammatory acne lesions are more visible. There may or may not be a few cystic acne lesions.

5 – Severe inflammatory acne dominates the area. Several numbers of comedones, pustules, papules, and cystic acne are also present.

Compared with the first two, this system gives a more detailed explanation of each category. This makes the system highly reliable as long as facial acne is concerned.

The US FDA (Food and Drug Administration) Scale

Recently proposed by the US FDA, this scale uses a 5-point system to assess acne. The five categories range from:

Clear – Neither inflammatory nor non-inflammatory lesions are present

Almost clear – A few non-inflammatory lesions with (or without) one pustule or papule

Mild – Some non-inflammatory lesions with a few pustules or papules. No nodules can be found.

Moderate – Several non-inflammatory lesions with some inflammatory lesions. There may be one small nodule.

Severe – There are several non-inflammatory and inflammatory lesions. A few nodules are also present.

This scale, like the IGA, is based on text descriptions. It provides more reliability as its descriptions are clearer and more straightforward.

EDF (European Dermatology Forum) Acne Treatment Guideline

This system is based on acne severity grades and the number of lesions. The results are then divided into 4 categories:

  • Comedonal acne – Non-inflammatory lesions such as whiteheads or blackheads
  • Papulopustular acne – A mixture of inflammatory (pustules and papules) and non-inflammatory lesions. The inflammatory lesions should be no more than 5 mm in diameter.
  • plus
    Nodular/conglobate acne – Nodules are defined as inflammatory acne that are more than 5 mm in size. They are often seen in larger areas and frequently result in painful lesions.
    Conglobate acne is the most severe form of acne vulgaris and is likely to cause scarring and searing. It is commonly found in men with super oily skin.
    This category is characterized by comedones scattered around papules and tender nodules. It is commonly found on the upper limbs and the trunk (sometimes down the buttocks) and less likely on the face.
  • plus
    Other acne variants – These are unusual and severe variants that are complications of acne with other diseases.
  • Late-onset, persistent acne
  • chevron-right
    Acne in neonates and infants
  • chevron-right
  • chevron-right
    Oil/tar acne
  • chevron-right
    Mechanical acne
  • chevron-right
  • chevron-right
    Rosacea fulminans
  • Gram-negative folliculitis
  • Acne fulminans


If you think you can handle all zits and pimples the same way, think again.

Acne is classified based on its severity.
Meaning, if you have light acne, you shouldn’t treat it as if it were a severe one. And vice versa.

If you’re wondering why your current medications don’t work, this acne severity scale hopefully showed you why. Perhaps you’ve been placed in the wrong category and are using the wrong treatments in the first place.
So, the next time you visit your dermatologist, make sure to ask questions on how bad your acne is and what scale he’s using.

What is your acne severity scale? How is your dermatologist treating it? We’d love to hear from you!

Hannah Do

Hannah is the founder of ThankYourSkin. Having personally battled acne during her younger years, she aspires to provide an invaluable guide to anyone suffering from it.


  1. Well I am kind of very sensitive towards Acne and other health issues. Thank you very much for sharing your insights as always said” prevention is better than cure”. You have clearly described different kind of acne conditions and this article will be helpful to a lot of people.

  2. Hi Hannah,
    Great Tips. It surely helps to those who have acne on their face.
    Thank you very much for sharing this article!
    It’s better to prevent rather than cure.

  3. I have the problem with acne skin but after reading this article now I’m aware of skin problems and you give good tip about this. thank you for this informative article!!

  4. It is indeed a nice and comprehensive blog. Many women face acne trouble due to hormonal changes. This blog will help them know the right reason behind their problem and will also help them treat it well.

  5. The information about acne is great. Even I myself had acne in my back which can be taken of moderate severity. But luckily these are reduced now. Many women suffer from acne problems. This article will be helpful to them. Thanks, Hannah for this excellent article.

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