Pathophys - Acne Flashcards
true or false
bacteria causes acne
FALSE
they get trapped in the mass of skin cells and sebum, allowing growth more rapidly, but it is NOT THE PRIMARY CAUSE
primary cause is abnormal growth of skin cells and collection of sebum
bacteria get TRAPPED in these skin cells and sebum, allowing them to grow more rapidly. they’re a CONSEQUENCE, or secondary cause
true or false
acne is chronic
true
acne is a chronic skin disorder of ______ that occurs why?
chronic disorder of HAIR FOLLICLES
occurs due to a blockage by SKIN CELLS AND SEBUM
acne occurs when……
dead skin cells and oil (sebum) from the skin clogs hair follicles
what is a comedone?
a hair follicle that has been clogged by dead skin cells and sebum
how are comedones important in the development of acne
they allow the excess growth of CUTIBACTERIUM ACNES – a commensal skin bacteria
this moist environment is ideal for bacteria to grow
true or false
the commensal bacteria, cutibacterium acnes, is responsible for the formation of a comedone and the start of acne
FALSE
the cause is a hair follicle clogged by SKIN CELLS AND SEBUM
the bacteria gets trapped AFTER THIS CLOG
true or false
cutibacterium acnes is a commensal bacteria
true
comedones start as what and progress to what?
starts as microcomedones and they enlarge to form PIMPLES
name 2 different types of pimples and why they present this way
whiteheads and blackheads
white heads are the result of a DEEP microcomedone that is closed
black heads are a SUPERFICIAL microcomedone that is open to air, and allows the oxidation of melanin – that’s why it has a black color
explain how acne can cause skin scarring and pus-filled raised areas (pimples)
when the microcomedone gets a lot of sebum and bacteria trapped inside, the bacteria can invoke the inflammatory process – causing the formation of a pus-filled raised pimple as well as tissue damage and scarring of the skin
what is the major risk factor for acne
GENETICS
true or false
the risk of developing acne is largely inherited
true
explain how acne is genetically linked
genetics control ANDROGEN PRODUCTION
androgens regulate the formation of sebum. if too many – too much sebum production
______ traps _______- in _______ to form a comedone
sebum traps dead skin cells in hair follicles to produce a comedone
what can cause increased sebum production
androgens
true or false
acne is likely of polygenic inheritance
true
acne is associated with ___ syndrome
why
XYY syndrome
“super male” - extra Y chromosome
there is high rate and severity of acne, as well as hair growth on the edge of the ear
name 2 hormones that seem to be the principle drivers in acne formation
androgens
growth hormone
name 2 androgens that are involved in acne formation
testosterone
DHT - dihydrotestosterone
acne still develops in those with androgen insensitivity
what can you conclude from this?
androgens are not the lone essential cause for acne – another main cause is IGF-1 (insulin like growth factor)
true or false
both males and females produce androgens and estrogens
true - just in varying amounts
where are androgens and estrogens made
in the adrenal cortex
how can increased androgens cause acne
they stimulate the growth of skin cells and increased production of sebum – cause hair follicle to clog and bacteria can get trapped too
how is it that the onset of acne is typically at puberty
increase in hormones!! (androgens and insulin like growth factor)
clogs follicles through increased sebum production and growth of skin cells
explain the role of cutibacterium acnes in acne
it is COMMENSAL – normally grows on the skin and has protective function
it is ANEAROBIC - does not need oxygen to grow
therefore, when trapped in sealed comedone with sebum and dead cells, it can easily grow even without oxygen
how are mites related to the formation of acne
infections with mites (particularly demodex) is associated with formation of comedones and acne
true or false
some strains of c. acnes are associated with normal skin and other strains are associated with acne
true
what kind of professionals often have an increased risk in formation of acne and why
athletes
causes by the mechanical obstruction of hair follicles – obstructed bc of the equipment they wear such as helmets
true or false
mechanical obstruction of the skin is not thought to play a role in acne
false - it is
ie: athletes and their equipment (helmets)
name 6 types of drugs that have been shown to worse pre existing acne
what are they all associated with?
testosterone
bromides
glucocorticoids
hydantoin
iodides
isonaizid
all associated with cell growth
the blockage of hair follicles occurs due to ___ events:
4 events:
increased sebum production
excessive deposition of keratin
comedone formation
colonization of the follicle by bacterium (usually C. acnes)
what is at the heart of developing acne?
what is the overarching event?
the 4 events that lead to the blockage of hair follicles – increased sebum production, excessive deposition of keratin, comedone formation, colonization of follicle by c. bacterium
OVERARCHING EVENT IS CHANGES IN HORMONE PRODUCTION
what is DHEA-S
a hormone whose levels are increased by the adrenal glands at puberty
leads to increased sebum production and growth of skin bacteria (C. acnes) and skin cells
true or false
while bacteria is NOT the cause of acne, it can enlarge the damage
TRUE
bc it invokes the inflammatory response – bc it binds and activates TLRs (toll like receptors) and increases secretion of cytokines like IL-1A
TNFa, IL8, LTB4
also the bacteria themselves produce enzymes that can damage tissue and form scars
as mentioned, bacteria invokes the inflammatory response and causes an increase in cytokines
what are 3 results of this
increased skin cell production
trapping of cells in the sebum
excessive growth and trapping = COMEDONE FORMATION
true or false
the bacteria themselves do not cause injury, but only indirectly through invoking the inflammatory process
FALSE - they can cause injury by releasing enzymes themselves that damage tissue
enzymes can cause phagocytes to release metalloproteases which damage tissue
what is squalene and its role in acne development
a component of sebum
when it is oxidized, it activates NFKB, which secretes IL-1A AND increases 5-lipooxygenase activity
this leads to increase in LKB4 (leukotriene B4) — a promoter of inflammation
inflammation causes local tissue death and scarring
