Dermatology Flashcards
Single most appropriate diagnostic test for allergic contact dermatitis?
Skin patch testing
With what is acanthosis nigricans most commonly associated with?
obesity
With which malignancy is thrombophlebitis migrans associated with?
pancreatic cancer
With which condition is a “herald patch” associated?
Pityriasis rosea-self limiting rash (up to 2 months)
Initial management of lichen sclerosus?
if confident in diagnosis in GP can start 3 month trial of topical dermovate (clobetasol proprionate 0.05%) along with soap substitute and barrier preparation
if not confident in dx/tx failure/considering surgery then r/f to special vulval clinic
With which condition might the generalised form of granuloma annulare (often a ring of small firm bumps over back of forearms/hands/feet, may burn/itchy) be associated?
diabetes
How is the weighted 7 point checklist used in 2ww referral criteria for suspected melanoma?
For suspicious pigmented skin lesion, score 3 or more-refer. Major criteria (each score 2):-change in size -irregular shape -irregular colour Minor criteria (each score 1): -oozing -inflammation -largest diameter 7mm or more -change in sensation
Drugs that can trigger bullous pemphigoid?
gliptins
diuretics
neuroleptics/antipsychotics
1st line tx of bullous pemphigoid?
potent topical corticosteroid e.g. dermovate
oral pred often needed if topical application not feasible
if steroids not tolerated/CI or disease relapsing can give high dose doxycycline (100mg BD)
severe cases may require other immunosuppressants or even IV Ig, rituximab or omilizumab
Maximum duration that a potent corticosteroid should be applied to 1 site continuously for in the management of chronic plaque psoriasis?
8 weeks
4 weeks for a very potent corticosteroid
How long must pregnancy be avoided for when a patient stops taking acitretin?
2 years
Initial tx of hidradenitis suppurativa?
tetracycline Abx e.g. lymecycline or doxycycline
1st line tx of comedonal acne?
topical retinoid e.g. adapalene
2nd line-azelaic acid
1st line PO Abx for mild to moderate pustular/papular acne not responding to topical tx or widespread?
lymecycline or doxycycline
lymecycline 408mg OD-if not responding after 6/52 switch to doxycycline 100mg OD
combine with topical tx ideally BPO, if not then topical retinoid
if pt does not respond to two types of PO Abx, especially if acne starting to scar, should r/f for consideration of isotretinoin
Why should macrolides generally be avoided in acne management?
high levels of P.acnes resistance
but are 1st line in pregnancy and children under 12
In which medical condition is isotretinoin contraindicatied?
hyperlipidaemia
Key points of Pregnancy Prevention Programme for women on PO isotretinoin or other PO retinoids?
- regular pregnancy tests-exclude pregnancy a few days before treatment, every month during tx and 4 weeks after stopping tx.
- practice effective contraception-for at least 1 month before tx, during tx and for at least 1 month after stopping tx. Advised at least 1 method, ideally 2. POPs not effective.
Blood monitoring of patients on isotretinoin?
LFTs and serum lipids before starting tx, at 1 month and then every 3 months
1st line tx for chronic plaque psoraisis?
potent topical corticosteroid and Vitamin D analogue, both applied once daily (one in the morning and one in the evening)
for up to 4 weeks as initial tx
if no improvement after 8/52 offer Vit D analogue twice daily, if still no improvement after 8-12/52 offer potent corticosteroid twice daily or coal tar preparation applied once or twice daily
Management of scalp psoriasis?
-POTENT topical corticosteroid applied once daily for 4/52, if no improvement then use different formulation of steroid and/or a topical agent to remove scale before applying the steroid e.g. salicylic acid
Management of face, flexural and genital psoriasis?
- mild or moderate potency topical corticosteroid applied once or twice daily for maximum of 2 weeks
- if unsatisfactory response or requiring continuous treatment, offer a calcineurin inhibitor BD for up to 4 weeks as 2nd line treatment-only to be prescribed if specialist in managing psoriasis. NICE recommend referral to dermatology if there is treatment failure with steroids.
Types of phototherapy used in managing psoriasis?
UVB for guttate and plaque psoriasis
PUVA for plaque or palmo-pustular psoriasis
1st line tx for vitiligo?
face-topical tacrolimus ointment (protopic) 0.1% BD for 6 months
extra facial sites-potent topical corticosteroid e.g. mometasone 0.1% cream for 3 months
What proportion of children develop atopic eczema if both parents are affected?
80%
60% if 1 parent affected
When should a patient with guttate psoriasis be urgently referred to dermatology?
if covers more than 10% of body surface area
How long should topical corticosteroids be continued for after flare of eczema has been brought under control?
for a further 48 hours
2 different options for maintenance tx of chronic eczema (not involving face, flexural or genital areas?
- step down treatment-topical corticosteroid at lowest potency that controls the eczema, usually step down from potency used in acute flare
- intermittent treatment-weekend therapy or twice weekly therapy-using usual topical corticosteroid
mild topical corticosteroid for face, flexural or genital eczema
Ratio of quantity of emollients to steroids in management of eczema?
10:1
What investigations are required for all patients presenting with a diffuse alopecia?
FBC, ferritin and TFT
Risk if isotretinoin is combined with tetracyclines?
benign intracranial hypertension
