Having (adult) acne is painful both physically and mentally. Have you tried to look up information online and seek help from professionals? Did you get unsolicited advice from your families/ friends or even strangers? Lots of information are floating around the internet. After reading tons of posts, you still have no ideas what treatments will work on you.

Here on my blog, my goal is to gather information from evidences (e.g. journals, books, websites) and share them to the public so that everyone can learn a bit more without confusion.

In this “Acne 101” page, we will discuss about acne types and different factors causing acne. We will also explore the relationship between foods & lifestyles and acne. 

And now, let’s start by knowing different types of acne first!


Acne (Acne Vulgaris) can be subdivided into 2 categories – inflammatory and non-inflammatory lesions [1]


Photo credit: Moore Clinical Research

Non-inflammatory – Comedones (whitehead & blackhead)

Blackhead (open comedones): clogged follicles which exposing to the air
Whitehead (closed comedones): clogged follicles without an opening

Inflammatory – Papules-> Pustules -> Nodules -> Cysts [2]

Papules: raised lesions in <1cm in diameter
Pustules: raised lesions in <1cm in diameter and filled with pus (=inflamed)
Nodules: large and inflamed, firm to touch which stay underneath for a long time
Cysts: large and inflamed, softer than nodules because filled in pus and deep in the skin 

Nodules and cysts are quite similar but different! See the below photo for easier understanding…

Photo credit: Viabuff.com

[1] Tan AU, Schlosser BJ, Paller AS. A review of diagnosis and treatment of acne in adult female patients. International journal of women’s dermatology. 2018 Jun 1;4(2):56-71.

[2] Heng AH, Chew FT. Systematic review of the epidemiology of acne vulgaris. Scientific reports. 2020 Apr 1;10(1):1-29.