Derm Lecture 2 Flashcards
(99 cards)
acne epidemiology
- Most common cutaneous disorder affecting adolescents & young adults
- Resolves in 3rd decade
- Post-adolescent acne affects women
- Adolescent acne affects males
acne is a disease of?
acne is a disease of pilosebaceous follicles
4 factors of acne pathology
- follicular hyperkeratinization (turning over of dead skin cells)
- increased sebum production
- Cutibacterium acnes w/in the follicle
- Inflammation
acne pathogenesis
- Sebaceous glands enlarge & sebum production increases during pre-puberty
- Sebum provides a growth medium for C. acnes
- Microcomedones (pores) provide an anaerobic lipid-rich environment for bacteria
- Inflammation results in the proliferation of C. acnes
what are the 3 types of acne lesions?
closed comedone - whitehead
open comedone - blackhead
inflammatory papules and nodules
what is a closed comedone?
whitehead - type of acne lesion
Accumulation of sebum and keratinous material converts a microcomedone into a closed comedone
what is a open comedone?
blackhead - type of acne lesion
follicular orifice is opened w/continued distension forming an open comedone – densely packed keratinocytes, oxidized lipids, and melanin all contribute to dark color
what are inflammatory lesions for acne?
type of acne lesion
follicular rupture contributes to this; proinflammatory lipids & keratin are extruded into the surrounding dermis leading into inflammatory papules & nodules
how do androgens contribute to the development of acne?
through stimulating the growth and secretory function of sebaceous glands
most circulating androgens are produced by what glands? and others, that aren’t, are produced by what glands?
most produced by adrenal glands, others produced by sebaceous glands
who and how does infantile acne occur in?
occurs as a result of elevated androgen levels produced by the adrenal glands in girls and by adrenal and testes in boys
androgen levels fall by age 2 and acne improves
how does puberty contribute to causing acne?
onset of acne correlates with the rise in serum DHEA-S levels that occur as puberty approaches
higher DHEA-S found in prepubertal girls with acne than those w/out
do the majority of pts with acne have androgen excess or normal androgen levels?
normal androgen levels
what conditions do you see hyperandrogenism in?
PCOS
congenital adrenal hyperplasia
adrenal or ovarian tumors
what external factors contribute to acne?
soaps, detergents and astringents - remove sebum from the skin surface BUT DO NOT ALTER SEBUM PRODUCTION
repetitive mechanical trauma like scrubbing may worsen acne by rupturing comedones and promoting inflammatory lesions
turtlenecks, bra straps, shoulder pads, and helmets may produce acne mechanica - occlusion of the pilosebaceous follicles leads to comedone formation
major causes of drug induced acne
- glucocorticoids
- phenytoin
- lithium
- isoniazid
- epidermal growth factor receptors inhibitors
- androgens
- corticotropin
- disulfiram
milk and acne
natural hormonal compounds of milk or other bioactive molecules in milk could exacerbate acne
consumption of milk has been associated with increased levels of insulin like growth factor (IGF)
family history and acne
- Case controlled studies show a more than 3 fold risk among individuals with affected first degree family members
- Twin studies support heritable nature of cases of severe acne
Insulin resistance and acne
-May stimulate increased androgen production and is associated with increased serum levels of IGF-1
diagnosis of acne
PE, Type and location of acne
Endocrine function
- Hyperandrogenism - PCOS is most common cause
- Sx’s of PCOS = menstrual irregularity, hirsutism, acne, ovarian cysts, insulin resistance, acanthuses nigrans
- May adrenal or ovarian tumor
labs to run for acne
- DHEA-S
- Total testosterone
- Free testosterone
First line tx for mild acne
Benzoyl Peroxide (BP) or topical retinoid
OR
Topical combination: BP + antibiotic or retinoid + BP or retinoid + BP + antibiotic
First line tx for moderate acne
Topical combination: BP + antibiotic or retinoid + BP or retinoid + antibiotic
OR
Oral abx + topical retinoid + BP
OR
Oral abx + topical retinoid + BP + topical abx
First line tx for severe acne
Oral abx + BP + abx
or
retinoid + BP
or retinoid + BP + abx
OR
isotretinoin