Dermatology Flashcards
Actinic keratoses features
- Premalignant lesions in sun exposed areas
- Crusty, scaly lesions
Actinic keratosis mx
- Topical 5-fu
- Topical imiquimod
- Cryotherapy
- Curettage / cautery
Skin disorders in pregnancy and basic features
Polymorphic eruption of pregnancy
- pruritic erythematous eruption
- last trimester
Pemphigoid gestationis
- pruritic blistering lesions
- peri-umbilical before spreading
- 2nd or 3rd trimester, rarely seen in 1st pregnancy
Melasma
- large flat hyperpigmented macules
- cheeks, forehead, nose, upper lip
- resolves after delivery
- also HRT / COCP use
Polymorphic eruption of pregnancy mx
- emollients
- mild topical steroids
- oral steroid
Pemphigoid gestationis
PO steroids
Dermatitis herpetiformis features
- inflammatory skin condition assoc w/ coeliac
- pruritic, vesicular, blistering lesions on EXTENSORS
Dermatitis herpetiformis ix
Skin biopsy: IgA deposition granular pattern (upper dermis)
Dermatitis herpetiformis mx
Dapsone
- monitor fbc (risk haemolytic anaemia, agranulocytosis)
- be aware peripheral neuropathy
Gluten free diet (ix coeliac)
Acne rosacea mx
All: suncream, camouflage creams
1) topical metro
- topical brimonidine for predominant flushing
- Laser therapy: for predominant telangiectasia
2) systemic abx e.g. oxytetracycline
Shingles mx
1) PO aciclovir
2) Simple analgesia
3) Neuropathic drugs e.g. pregabalin
4) Corticosteroids PO (acute only)
Shingles vaccine
Live attenuated VZV
All patients 70-79
Contraindicated: immunosuppression
Pityriasis rosea features
- can be preceded by prodromal illness
- Hypopigmented herald patch trunk
- then erythematous, oval, scaly patches ‘fir tree’ distribution
Pityriasis rosea mx
None
Self limiting 6-12 weeks
Erythema multiforme causes
- viruses: HSV
- bacteria: Mycoplasma, Streptococcus
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
- CTD: SLE, sarcoid
- malignancy
- idiopathic
Erythema nodosum causes
- Infection: streptococci, TB, brucellosis
- systemic disease: sarcoidosis, IBD, Behcet’s
- malignancy / lymphoma
- drugs: penicilin, sulphonamides, COCP
- pregnancy
Pyogenic granuloma features
- benign lesions
- small brown spot -> raised -> spherical
- may catch and bleed
- trauma, pregnancy, young women
Mx: cryo, cautery, excision
Pyoderma gangrenosum features
- usually lower limbs
- small red papule -> deep, red, necrotic ulcers
- violaceous border
- +/- fever, myalgia
Causes pyoderma gangrenosum
- idiopathic 50%
- IBD, PBC
- RA / SLE
- haem: lymphoma, leukaemia, MGUS, myeloproliferative disorders
Mx pyoderma gangrenosum
1) PO steroids
2) Consider immunosuppresion: ciclosporin / infliximab
Complication of psoriasis
- 10% psoriatic arthropathy
- metabolic syndrome
- CV disease
- VTE
- psychological distress
Pemphigus vulgaris features
- autoimmune disease vs desmoglein 3 (cadherin)
- ashkenazi jewish
- can be associated with coeliac
- flaccid skin blistering
- Nikolsky’s sign
- mucosal involvement
IX: direct immunofluorescence, acatholysis (biopsy)
Pemphigus vulgaris mx
1) PO steroids
2) immunosuppression
Factors that exacerbate psoriasis
- trauma
- alcohol
- beta blockers
- ACEi
- NSAIDs
- lithium
- antimalarials (chloroquine and hydroxychloroquine)
- infliximab
- withdrawal of systemic steroids
Squamous cell carcinoma features
- scaly, crusted lesion
- painful
- may bleed / ulcerate
- might be within actinic keratosis
RFs for squamous cell carcinoma
- elderly males
- sun exposure
- actinic keratosis
- smoking
- immunosuppressing disease e.g. CLL, HIV, organ transplant
- immunosuppresant drugs e.g. azathioprine, infliximab
Mx squamous cell carcinoma
1) excision
+ adjuncts for locally advanced / metastatic disease
- radiotherapy
- cemiplimab (PD-1 and PD-2 inhibitor)
Thromboangiitis obliterans / Buerger’s disease
- inflammatory nonatherosclerotic peripheral vascular disease & limb ischaemia
- young male smokers
- angio: patchy occlusion distally, corkscrew collaterals
- mx: stop smoking
Necrobiosis lipoidica
- usually on both shins and are rarely found in other sites
- oval, round or irregular plaques
- yellow / red and shiny
- centre starts to become pale with telangiectasia
- asymptomatic or painless
- may ulcerate after injury
- seen in insulin-dependent diabetes
- mx: systemic steroids, immunosuppression
Seborrhoeic keratosis
- benign ageing spot
- stuck on, brown, waxy appearance
- Leser-Trélat sign: sudden appearance of several lesions suggests underlying cancer, usually GI
Seborrhoeic dermatitis
- malassezia furfur greasy, scaly, oily patches / plaques - affects face, nasolabial folds, scalp - gets better with sun - RFs: HIV, Parkinson's - complications: blepharitis, otitis externa
Mx: topical ketoconazole +/- steroids
Guttate psoriasis presentation
- 1st presentation of psoriasis
- OR flare of known psoriasis
- classically few weeks post strep throat
- tear trop scaly papules over trunk and limbs
- rarely affects hands / feet
Guttate psoriasis mx
- usually self resolve in 2-3 months
- topical agents as for psoriasis: emollients, topical steroid / vit D analogue, coal tar preparation
- UVB phototherapy
- tonsillectomy if recurrent
Vitiligo mx
- sun block
- camouflage make-up
- topical corticosteroids may reverse the changes if applied early
- topical tacrolimus
- phototherapy
Basal cell carcinoma mx
- surgical removal
- curettage
- cryotherapy
- topical cream: imiquimod, fluorouracil
- radiotherapy
Scabies
1) 5% permethrin - apply to whole body, leave for 6 hours, repeat in 1 week. All household contacts to do the same
2) 0.5% malathion
Immunosuppressed with crusted scabies: isolate and ivermectin
Bullous pemphigoid features
- Itchy, tense blisters
- usually spares mucosa
- usually heals without scarring
Bullous pemphigoid RFs
- elderly
- PD1 inhibitors e.g. pembrolizumab
- furosemide
- captopril
- penicillin & other abx
- sulfasalazine
Bullos pemphigoid IX and MX
IX: skin biopsy - immunofluorescence shows IgG and C3 at the dermoepidermal junction
Mx:
- emollients
- topical steroids (if <10%)
- systemic steroids
- abx e.g. doxycycline
- immunosuppression
Erythroderma
- any rash involving >95% skin
Typical causes
- eczema
- psoriasis
- drugs e.g. gold
- lymphomas, leukaemias
- idiopathic
Bowen’s disease
Intra-epithelial SCC - 3% risk of becoming invasive cancer
Bowen’s disease mx
- topical 5-fluorouracil or imiquimod
- cryotherapy
- excision
Scalp psoriasis mx
1) 4 weeks topical steroid
2) Different formulation e.g. shampoo +/- agent to remove scale e.g. emollient, agent with salicylic acid
Flexural / genitial psoriasis
1) 2 weeks max mild-mod potency topical steroid
Pityriasis versicolor features
- malassezia furfur
- scaly hypopigmented patches, itchy
- usually on trunk
- RFs: immunosuppression, malnutrition, Cushing’s
Pityriasis versicolor ix & mx
- Ix:
- skin scrapings
- yellow/green under Wood’s lamp
- Mx: ketoconazole topical -> oral itraconazole
Stevens-Johnson Syndrome features
- 1-4 weeks post drug exposure
- maculopapular lesions, target lesions
- my develop vesicles / bullae
- Nikolsy sign
- mucosal involvement
- fever, arthralgia
Stevens-Johnson Syndrome causes
- penicillin
- sulphonamides e.g. sulfamethoxazole in co-trimox
- lamotrigine, carbamazepine, phenytoin
- allopurinol
- NSAIDs
- combined oral contraceptive pill
SJS / TEN overlap
- <10% is SJS
- 10-30% SJS/TEN overlap
- > 30% is TEN
Keratoacanthoma
- benign epithelial tumour
- fast growing
- initially fleshy -> keratinised centre
- following minor skin trauma OR areas of sun damaged skin
- Mx: excise to exclude SCC
Solar lentigo vs lentigo maligna
- Lentigo maligna is more irregular
- can progress to lentigo maligna melanoma
Lichen planus
- purple, polygonal, pruritic, papules / plaques
- oral lesions can occur
- white line pattern over the surface ‘wickham’s striae’
- koebner phenomenon
- betablockers, thiazide diuretics, anti-malarials can precipitate
mx: topical steroids
Causes of acanthosis nigricans
- gastrointestinal cancer
- diabetes, PCOS, obesity, Cushing’s disease
- acromegaly, hypothyroidism
- familial
- Prader-Willi syndrome
- drugs: oral contraceptive pill, nicotinic acid
Chondrodermatitis nodularis helicis
Painful nodule on the ear
Psoriasis management
ALL regular emollients
1) 4 weeks potent topical corticosteroid OD + OD vit D analogue
2) BD vit D analogue
3) BD potent corticosteroid OR coal-tar preparation
Phototherapy
1) narrow band UVB
2) Psoralen + UVA
Systemic therapy - failed above / can’t tolerate phototherapy / >10% body / severe uncontrolled sx with poor QoL
1) methotrexate
2) ciclosporin if intolerant / doesn’t work / want to conceive
Biologics
infliximab, etanercept and adalimumab
ustekinumab
Palmar-plantar erythrodysesthesia
- days to months into chemo treatment
- tingling or numbness first in the fingers and palms and then toes and soles of the feet
- followed by an erythematous rash which can desquamate, blister and ulcerate
- mx: supportive or delay chemo
Leukoplakia
- white oral mucosal lesions similar to candida
- can’t be rubbed off
- hard
- assoc HIV
Mx: ART if HIV
Drugs causing photosensitive skin rashes
- abx: tetracyclines, fluroquinolones, sulphonamides
- NSAIDs
- furosemide, bumetanide
- sulphonylureas
- neuroleptics e.g. chlorpromazine
- antifungals e.g. terbinafine, itraconazole
- amiodarone, diltiazem
Mx photosensitive drug rash
- discontinue
- topical steroid
- systemic steroid if severe
Tinea features and management
- annular lesion
- alopecia if on scalp
- ix: wood’s lamp fluorescence
- mx
1) ketoconazole cream
2) oral itraconazole
3) terbinafine PO
Lichen planus mx
1) topical steroid
2) oral pred
Usually resolves in 6-18 months
Erythema nodosum HLA linkage
B27
Mx erythema nodosum
1) NSAIDs
2) topical K iodide
3) PO pred
Treatment of male pattern hairloss in women
1) topical minoxidil
2) PO finasteride (antiandrogen)
Acitretin and pregnancy
Avoid 4 weeks before starting
Avoid 3 years after completing
Pyoderma gangrenosum mx
1) topical steroids
2) PO steroids
3) Immunosuppressants: ciclosporin, MMF, anti-TNF
Discoid lupus
- photosensitive dermatosis
- 28% develop full SLE
Mx
1) sun block
2) topical stroids
3) hydroxychloroquine
4) immunosuppressants
Granuloma annulare
Circular lesion
Otherwise asymptomatic
Mx: months to self-resolve, otherwise topical steroids
