Papule, Pustule, Pimple, Comedo, Lesion, Cyst & Abscess Explained

[Guide]

Papules 

A papule (/ˈpæpjuːl/) is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm. It can be brown, purple, pink or red in color, and can cluster into a papular rash. Papules may open when scratched and become infected and crusty. Larger non-blisterform elevated lesions may by termed nodules. Papules may have different shapes and are sometimes associated with other features such as crusts or scales. Wikipedia

Image - Wikipedia Commons

Pustule

"Pustule: A pustule is a small elevation of the skin containing cloudy or purulent material (pus) usually consisting of necrotic inflammatory cells. These can be either white or red." Wikipedia

Image - Wikipedia Commons

Pimple

"A pimple, zit or spot is a kind of comedo and one of the many results of excess oil getting trapped in the pores. Some of the varieties are pustules or papules....Some more severe pimples can lead to significant swelling and may appear on the back and chest." Wikipedia

Comedo

"A comedo is a clogged hair follicle (pore) in the skin. Keratin (skin debris) combines with oil to block the follicle. A comedo can be open (blackhead) or closed by skin (whitehead), and occur with or without acne." Wikipedia

Image - Wikipedia Commons

Lesion

"A lesion is any abnormal damage or change in the tissue of an organism, usually caused by disease or trauma....There is no designated classification or naming convention for lesions. Because the definition of a lesion is so broad, the varieties of lesions are virtually endless. Lesions can occur anywhere in the body that consists of soft tissue or osseous matter, though most frequently found in the mouth, skin, and the brain, or anywhere where a tumor may occur." Wikipedia

Lesion counts are discussed in the following post. 

Cysts (Blood-filled Pimples) 

Blood-filled pimples (cysts) are usually associated with cystic acne. For more information click here. A collection of pus is called an abscess, not a cyst. Picture of Cystic Acne 

Abscess
An abscess is usually not associated with rosacea but may be a co-existing condition. An abscess is a collection of pus that has built up within the tissue of the body. Wikipedia

Five Day Old Abcess - Image courtesy of WikiMedia Commons

Differentiation

Your dermatologist should differentiate papules, pustules, pimples, comedos, lesions, cysts, and abscesses from milium (plural milia).

[Guide]

This sweet man has been bringing his wife in to see me, and I have been treating a large skin cancer on her face, with her recently getting Mohs skin cancer surgery.  So, he is not directly a patient of mine, but I couldn't help but notice that he has so many comedones on his nose.  He tends to not pay much attention to himself, spending much of his energy and efforts making sure his wonderful wife is doing alright.  She has more disabilities than he does, in fact he looks amazing for 90 years old!

He has fantastic blackheads and whiteheads to extract.  As you may know, blackheads and whiteheads are also called open and closed comedones, and they are benign growths.  In his case, he has rosacea and rhinophyma, which causes increased thickening of the skin of the nose, increased oil production in the area, and very large pore that fill with keratinous material creating huge blackheads and whiteheads.
These don't need to be extracted, but certainly the appearance of the nose with improve greatly if they are.

Thank you so much for watching! Dr. Sandra Lee (aka Dr. Pimple Popper)