Derm Flashcards
which glands produce sebum?
pilosebaceous follicles in response to androgens
describe to pathophysiology of acne
increased androgen sensitivity. excess sebum production. obstruction of outlfow of sebum, leakage into surrounding dermis, colonisation with propionibacterium acnes
what is an open comedone?
blackhead
what is a closed comedone?
whitehead
what suggests moderate/ severe acne?
scarring, affecting trunk and lots of comedones
conservative management for acne
washing BD with soap, sunlight ?beneficial, OTC benzyl peroxide
what are first line treatments for acne vulgaris?
topical antibiotics (not alone as increased risk of resistance)
topical retinoids
benzoyl peroxide
what is a side effect of benzoyl peroxide?
dry/ irritated skin, start lowest strength e.g. 2.5% and persevere
which topical antibiotics can be used for acne?
clindamycin/ erythromycin
how long can systemic treatments for acne take to work?
allow 4 months to assess effects
which oral antibiotics can be used for acne?
tetracyclines- limacycline/ doxycycline
give an example of an oral retinoid?
isotretinion
give 3 side effects of isotretinoin
teratogenic
dry skin
myalgia (exercise related)
what are contraindications to isotretinoin?
tetracycline use- risk of benign intracranial HTN
POP (reduces effectiveness)
what treatment for acne can be used in F?
anti-androgens e.g. COCP
treatment for fungal nail infection
oral terbinafine
young adult with an abdominal herald patch, followed by erythematous, oval, scaly patches in a ‘fir-tree’ distribution
pityriasis rosea
what is RAST?
radioallergosorbent test- identifies IgE to specific antigens in eczema
pearly papules with central punctum
molluscum contagiosum
systemically unwell, extensive papules and blisters. history of eczcema
eczema herpeticum
what is the pathophysiology of ezcema?
IgE mediated T call autoimmune response
what bacteria most commonly causes secondary infection of eczema?
staph aureus
what are the 3 steps of emollient?
cream< lotion< ointment
name mild corticosteroids
1% hydrocortisone (<2 weeks/ 5 days on face)
if no effect eumvate
name potent corticosteroids
betnovate
dermovate (not on face, good if lichenification)
side effects of topical steroids
skin thinning
striae formation
telangectasia
cushings (rare)
what is Auspitz sign?
sctratch of scale causes capillary bleed, +ve for psoriasis
2 nail changes in psoriasis
pitting
onycholysis
pathophysiology of psoriasis?
t cell mediated- release cytokines resulting in keratinocyte proliferation
multiple small discoid plaques, scaly, following strep tonsillitis
guttate psoriasis
5 drugs that can precipitate psoriasis
BB Li anti malarials NSAIDs ACE-Is
4 extra-dermal manifestations of psoriasis
arthritis
IBD
uveitis
metabolic syndrome (DM-II, HTN, CVD)
what should always be co-prescribed with steroids in psoriasis?
vitamin D analogues e.g. calcitriol/ calciprotriol
True or false: in psoriasis start with least potent agent and titrate up
false: start with most potent agent
name 3 other topical treatments for psoriasis other than emollients/ steroids/ vit D analogues
coal tar preparations
salicylic acid (keratolytics)
retinoids
what can be used in secondary care for psoriasis?
phototherapy (UVB>UVA>PUVA)
retinoids
immunosuppression- methotrexate
biologics- infliximab
First line for psoriasis
Vit. D analogues +/- topical steroids + tar or salicylic acid ± UVB
what % of skin coverage in psoriasis warrants referral to secondary care?
> 10%
seborrhheic keratosis
flat topped/ warty, dark lesions in sun-exposed areas. reassure
what causes plantar warts (verruca)
HPV
treatment for verrucas
first line OTC salicylic acid
then: cryotherapy
slow growing tumour, rarely spreads
BCC
pearly nodule with a raised, red, edge. May be scaly. Often on the face.
BCC
treatment of solar keratosis
cryotherapy/ effudix
management of BCC
Medical- effidux
surgical- cryotherapy/ curretage/ cautery/ Moh’s
what do solar keratoses predispose to?
SCC
Solitary papule / nodule, often eroded at the centre, or crusty, purulent or bleeding
SCC
what name is given to SCC in situ
Bowen’s disease
management of SCC
edical- effidux (rare as no histology)
surgical- cryotherapy/ curretage/ cautery/ Moh’s
what checklist is used for melanoma
Glasgow 7 point checkilst
what mnemonic can be used for melanoma diagnosis?
ABCDE Assymetry Border- irregulr Colour Diameter >7mm Evolving
on biopsy of melanoma what predicts outccome?
Breslow thickness, >1mm indicates high risk of metastasis and need for sentinal node biopsy
how many naevi increase risk of developing melanoma
> 50 normal/ >2 atypical
Kaposi sarcoma
immunosuppression + HPV infection-> multiple purple plaques/ patches on skin + mucous membrane
what signs around a leg ulcer suggests a venous cause?
varicose veins oedema venous eczema haemosiderin deposition atrophie blanche
where are venous ulcers typically located?
around malleoli
where are arterial ulcers typically located?
areas of poor blood supply e.g. tibia/ toes
large, shallow ulcer, irregular border, pain reduced on elevation
venous ulcer
deep, punched out ulcer. Pain relieved by hanging leg over edge of bed
arterial ulcer
initially a smooth dome-shaped papule
rapidly grows to become a crater centrally-filled with keratin
keratoacanthoma
scabies management
permethrin 5%
