Acne
Acne Causes
Increased sebum and excess skin cells can clog skin pore
Overproduction of sebum
Those with acne secrete more sebum than unaffected individuals
Sebum is an oily/waxy substance secreted by the
skin's sebaceous glands used to lubricate the skin and hair follicles -
oddly however, the distribution of sebaceous glands and amount of sebum produced
doesnot correlatewithdryskin. Sebum is composed of triglycerides, free fatty acids,
wax, squalene, and a little cholesterol,with their proportions being altered in
a person with acne (more squalene and TGs and less free fatty acids and wax)
Altered Proportions of fats in Sebum of a person with acne
Overproduction of sebum can:
• Increase the incidence of clogged pores
• Stimulate inflammation- which further
promotes sebum production
• Provide nutrients for bacterial growth
• Influence other factors central to the pathogenesis
of acne vulgaris.
Sebum production in skin pores is increased by:
- Inflammation
- Increased
male hormones. Can occur in puberty, with hyperandrogenism,low blood sugar or low
blood sugar dips on a
blood sugar roller coaster ride , or taking
androgenic drugs.Androgen
presence is only partly involved, since sebum production activity also varies
with :
• Sebaceous gland receptivity
to androgens.
Central
problem in male acne and possible
role in female acne
• Sebaceous glands'ability
to metabolise or synthesize (from cholesterol).
Activity ofthe enzyme
Type-1 5α-reductase (converts
Testosterone or
DHEAS to more potent
DHT ) is higher in sebaceous glands
on the face, compared to other body areas not prone to acne.Hyperconversion of circulating
androgens (called hyperandrogenism)
and/or overproduction of androgens
by ovaries or adrenals (called hyperandrogeny) may have roles in
female acne.
• Sebaceous gland's
ability to more fully use circulating androgens
- Increased
INSULIN and INSULIN GROWTH FACTOR
(IGF-1). Can result from high blood
sugar or highs on
a blood
sugar roller coaster ride ;
For more detail:
What Regulates Sebum Production?
Hyperkeratotic plug / micro-comedone /whiteheads
Increased sebum and over-proliferation of skin
cells can create a hyperkeratotic plug. Faster skin cell regeneration
means more dead skin cells to be expelled, and the heavier "traffic"means
they have to be clumped together for the journey out. Dead cell clumps, "glued" together
with the increased sebum, invariably leads to "traffic jams" i.e. plug-blocked
pores.
- These impactions
contain. Corneocytes, bacteria, sebum and vellus hairs within the
follicular lumen, which may or may not inflame.
- Comedogenesis
begins in the lower infundibulum closely followed by kyperkeratosis of the sebaceous
duct
Kligman
- High IGF-1
levels causes skin cells (keratinocytes)
to multiply. Higher levels of
the hormone IGF-1, which stimulates cell growth and proliferation, have been well
documented as a factor in acne;
Aizawa
H, Niimura M, Elevated serum insulin-like growth factor-1 (IGF-1) levels in women
with postadolescent acne. J. Dermatol 1995 Apr;22(4):249-52.
