Skin Disorders B&B Flashcards
acne is inflammation of _____ glands
sebaceous
Acne is due to high Androgens
comedones
sebaceous ducts blocked by debris (excess keratin and sebum)
creates lipid-rich environment for bacteria to grow —> acne
open comedo = blackhead
closed comedo = whitehead (covered by skin)
what is the clinical use of topical benzoyl peroxide?
treats acne by breaking down keratin to unblock pores (comedolytic)
also bactericidal to propionibacterium acnes
which 2 antibiotics are typically used to treat acne?
clindamycin and erythromycin
bactericidal to propionibacterium acnes
how does isotretinoin (accutane) treat acne?
aka 13-cis-retinoic acid (vitamin A derivative)
binds nuclear receptors RAR (retinoic acid) and RXR (retinoid X)
this causes a decrease in keratin production —> less follicular occlusion
highly teratogenic (requires pregnancy test prior to taking)
seborrheic dermatitis - cause and treatment
red plaques with scale (flaky skin) on face and scalp - areas with lots of sebaceous glands
poorly understood but associated with fungal infection by Malassezia - treat with antifungals and corticosteroids
Patient is a 34yo M presenting to their dermatologist with a new dark brown pigmented lesion of uniform color. It is round and about 3mm wide. What is it most likely?
acquired (vs congenital) melanocytic nevus (mole): benign neoplasm of melanocytes
usually >6mm, uniform color, round/oval
bigger than 6mm or non-uniform color is suspicious for melanoma, rarely develop dysplasia/melanoma over time
junctional vs compound vs intradermal nevi
nevus = mole, due to overgrowth of melanocytes
junctional nevi: melanocyte growth along dermal-epidermal junction, common in children
compound nevi: melanocyte growth in epidermis and dermis
intradermal nevi: loss of junctional lesion, melanocyte growth only in dermis, common in adults
pseudofolliculitis barbae
aka razor/shave bumps, inflammation from trapped hairs
form firm papules/pustules, most often in black men
how and where does psoriasis appear?
chronic inflammatory skin disorder of well-demarcated plaques that are pink/salmon colored with silver-white scaling
most commonly on extensor surfaces - knees and elbows
which genes are associated with development of psoriasis?
believed to be autoimmune, associated with HLA-C (human leukocyte antigen)
what are the classic histological findings of psoriasis? (5)
- acanthosis: thickening of epidermis
- parakeratotic scaling: retained nuclei in stratum corneum, indicates hyperproliferation
- munro microabscesses: neutrophils in stratum corneum
- thickened stratum spinosum
- thinned/absent stratum granulosum
Auspitz sign is a positive indication of which skin disorder?
Auspitz sign: bleeding when a scale breaks in a patient with psoriasis
indicates the dermis blood vessels are very close to the epidermis surface
this also allows for neutrophils to migrate towards the surface in the epidermis (munro microabscesses)
what symptoms with patients with psoriasis develop outside of skin plaques? (2)
- nail pitting or onycholysis (separation of nail from nail bed)
- psoriatic arthritis: seronegative spondyloarthritis
which patients does rosacea most often affect?
adults >30 who are light-skinned, greatest risk in Celtics and Northern Europeans
inflammatory skin condition, chronic redness of nose/cheeks