Dermatology Flashcards
what is the pathophysiology of acne?
chronic inflammation +/- localised infection in pileosebaceous units within the skin. increased sebum preduction traps keratin and blocks the pulosebaceous unit leading to swelling and inflammation. Androgenic hormones increase production of sebum => increased in puberty
what are macules?
flat marks on skin
what are papules?
small lumps on skin
what are pustules?
small lumps with pus
what are comedones?
skin coloured papules due to blocked pilosebaceous units
what are blackheads?
open comedones with black pigmentation in the middle
what are ice pink scars?
small indentations that remain in skin after acne lesion heals
what are hypertrophic scars?
small lumps in skin that remain after acne lesions heal
what are rolling scars?
irregular wave like irregularies of the skin that remain after acne lesions heal
what acne medication if teratogenic?
retinoids
what is general advice for acne? 5
Avoid overwashing
Use non-alkaline synthetic detergent BD
Avoid oil based cosmetics and suncream
Avoid picking
Treatment may irritate skin initially
not enough evidence to support diets for acne
what are the 5, 1st line treatments for acne?
Topical benzoyl peroxide + Topical Adapalene, OD - Any severity
Topical Tretinoin + Topical Clindamycin, OD - Any severity
Topical Benzoyl peroxide + Topical clindamycin, OD - Mild-moderate
Topical adapalene + Topical benzoyl peroxide, OD + Oral lymecycline/doxycycline OD - moderate-severe
Topical azelaic acid BD + oral lymecycline/docycycline OD - moderate-severe
what contraceptive pill is best at reducing acne?
COCP (co-cyprindiol (Dianette)) - anti-androgenic effect
what is the last line option for acne (specialist)?
oral retinoids (isotretinoin (accutane))
what are 5 side effects of isotretinoin?
dry skin and lips
photosensitivity of skin
depression, anxiety, aggression, suicidal ideation
Stevens-johnson syndrome and toxic epidermal necrolysis
Sexual dysfunction
what is the name for head lice?
Pedicures hymns capitis
what are the 2 first line management options of head lice?
Wet combing - systematically removing head lice with comb
Dimeticone 4% lotion - left on for 8 hours then washed off - repeat after 7 days to kill hatchlings - physical insecticide
How long can it take for scabies infection to appear after initial infestation?
up to 8 weeks - usually begin in 3-6 weeks
what is the presentation of scabies? 4
Very itchy erythematous papules often excoriated with hemorrhagic crusts
Itching usually worse at night
Track marks where mites have burrowed - thin brown-grey line
Classically between finger webs but can affect whole body - usually spares back and head in adults
what is the management of scabbies?
Permethrin cream 5% - over 2 months old, to whole household
Applied all over body once weekly for 2 weeks, wash off after 8-12 hours
Also must wash all clothes and bedding on hot wash and hoover to destroy mites
How can scabies appear on genitals?
may be nodular even more itchy papules on genitals - usually indicative of sexually acquired scabies
what are Norwegian Scabies?
AKA Crusted scabies
In immunocompromised people
Mild/absent pruritus due to impaired immune response
Skin lesions generalised poorly defined erythematous fissured plaques covered by scales and crust - yellow-brown veracious aspect on bony prominences
need to be isolated
what are 2 tests that can be used to confirm scabies?
Ink burrow test - ink applied to suspect papule then wiped off with alcohol to remove surface ink - ink runs down burrow creating zigzag line
Microscopy of skin scrapings
what is the management of difficult to treat or Norwegian scabies?
Oral Ivermectin 200 micrograms/kg usually one dose, may be repeated a week later