Derm Flashcards
Acne classification
mild: open and closed comedones with or without sparse inflammatory lesions
moderate acne: widespread non-inflammatory lesions and numerous papules and pustules
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
acne mx
mild to moderate
- 1st line: 12-week course of topical combination therapy (adapalene & benzoyl peroxide / tretinoin & clindamycin / benzoyl peroxide & clindamycin )
- only benzoyl peroxide if pt wants to avoid others/ CI
moderate to severe
- 12wks: first 2 combinations above OR oral lymecycline/ doxycycline with topical adapalene/ benzoyl peroxide/ azelaic acid
- COCP are alternative to oral abx in women - like abx, should be used w topical.
- Dianette (co-cyprindiol) used as 2nd line - has anti-androgen effects. Increases VTE compared to other COCP
Oral isotretinoin: only under specialist supervision
IMPORTANT
- pregnancy is a contraindication to topical and oral retinoid treatment
- oral tetracyclines avoided in pregnant & breastfeeding & <12yrs. oral erythromycin used in pregnancy instead
- oral antibiotics needs to be co-prescibed with another topical therapy - but not topical abx!!
acne referral should be considered in the following scenarios:
mild to moderate acne has not responded to two completed courses of treatment
moderate to severe acne has not responded to previous treatment that includes an oral antibiotic
acne with scarring
acne with persistent pigmentary changes
acne is causing or contributing to persistent psychological distress or a mental health disorder
Actinic keratoses mx
prevention of further risk: e.g. sun avoidance, sun cream
fluorouracil cream: typically a 2 to 3 week course
topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
topical imiquimod
cryotherapy
curettage and cautery
antihistamins classification, examples & receptor
H1 inhibitors
Examples of sedating antihistamines:
chlorpheniramine
(have sedating & antimuscarinic SEs)
Examples of non-sedating antihistamines
loratidine
cetirizine
Athlete’s foot cause & mx
tinea pedis.
fungi in the genus Trichophyton.
topical imidazole, undecenoate, or terbinafine first-line
Bowen disease
1st line = topical 5-fluorouracil
cryotherapy
excision
Bullus pemphigoid vs pemphigus vulgaris
both autoimmune
Bullus pemphigoid
- sub-epidermal blistering, typically around flexures
- against hemidesmosomal proteins BP180 and BP230.
- no mucosal involvement
- immunofluorescence shows IgG and C3 at the dermoepidermal junction
Pemphigus vulgaris
- abs against desmoglein 3, a cadherin-type epithelial cell adhesion molecule
- mucosal ulceration is common & first px
- skin blistering- flaccid, easily ruptured vesicles and bullae
- Nikolsky’s sign
what can you use to assess the extent of the burn
Wallace’s Rule of Nines: head + neck = 9%, each arm = 9%, each anterior part of leg = 9%, each posterior part of leg = 9%, anterior chest = 9%, posterior chest = 9%, anterior abdomen = 9%, posterior abdomen = 9%
Lund and Browder chart: the most accurate method
palmar surface is roughly equivalent to 1% of total body surface area (TBSA). Not accurate for burns > 15% TBSA
depth of the burn px
1st degree - Superficial epidermal - Red and painful, dry, no blisters
2nd degree - Partial thickness (superficial dermal) - Pale pink, painful, blistered. Slow capillary refill
2nd degree - Partial thickness (deep dermal). Typically white but may have patches of non-blanching erythema. Reduced sensation, painful to deep pressure
Full thickness - Third degree- White (‘waxy’)/brown (‘leathery’)/black in colour, no blisters, no pain
burns Referral to secondary care criteria?
superficial dermal burns of more than 3% TBSA in adults, or more than 2% TBSA in children
all deep dermal and full-thickness burns.
superficial dermal burns involving the face, hands, feet, perineum, genitalia, or any flexure
circumferential burns of the limbs, torso, or neck
any inhalation injury
any electrical or chemical burn injury
suspicion of non-accidental injury
Dermatitis herpetiformis dx
skin biopsy: direct immunofluorescence shows deposition of IgA in a granular pattern in the upper dermis
Eczema herpeticum mx
( primary infection of the skin by herpes simplex virus 1 or 2, usually in atopic eczema )
admitted for IV aciclovir.
Causes of erythema multiform
viruses: herpes simplex virus (the most common cause), Orf
idiopathic
bacteria: Mycoplasma, Streptococcus
drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
connective tissue disease e.g. Systemic lupus erythematosus
sarcoidosis
malignancy
erythema multiforme major is associated with mucosal involvement.
Erythema nodosum causes
infection:
streptococci
tuberculosis
brucellosis
systemic disease:
sarcoidosis
inflammatory bowel disease
Behcet’s
malignancy/lymphoma
drugs:
penicillins
sulphonamides
combined oral contraceptive pill
pregnancy
Erythrasma features
asymptomatic, flat, slightly scaly, pink or brown rash usually found in the groin or axillae.
overgrowth of the diphtheroid Corynebacterium minutissimum
Topical miconazole
Fungal nail infection causes
dermatophytes
account for around 90% of cases
mainly Trichophyton rubrum
yeasts
account for around 5-10% of cases
e.g. Candida
non-dermatophyte moulds
Fungal nail infection ix & mx
Ix - nail clippings +/- scrapings w microscopy & culture
mx
- if pt unbothered - leave it
- if dermatophyte or Candida infection is confirmed: topical amorolfine if limited; oral terbinafine if more extensive dermatophyte infection; oral itraconazole if more extensive Candida infection
Hereditary haemorrhagic telangiectasia fx
autosomal dominant condition
Osler-Weber-Rendu syndrome
multiple telangiectasia over the skin and mucous membranes.
epistaxis : spontaneous, recurrent nosebleeds
telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
family history: a first-degree relative with HHT
hirsutism & hypertrichosis mx
hirsutism- androgen-dependent hair growth
- weight loss if overweight
- cosmetic: waxing/bleaching
- COCP
- facial hirsutism: topical eflornithine - contraindicated in pregnancy and breast-feeding
hypertrichosis- androgen-independent
Hyperhydrosis tx
topical aluminium chloride preparations are first-line.
(iontophoresis, botulinum toxin, surgery)
Impetigo mx
- hydrogen peroxide 1% cream for ‘people who are not systemically unwell or at a high risk of complications’
- topical fusidic acid - topical mupirocin if resistance suspected
Extensive disease
oral flucloxacillin
oral erythromycin if penicillin-allergic
children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment
Keloid scars common sites & tx
(in order of decreasing frequency): sternum, shoulder, neck, face, extensor surface of limbs, trunk
more common in young people with dark skin
intra-lesional steroids
excision maybe
main features of a melanoma
The main diagnostic features (major criteria):
Change in size
Change in shape
Change in colour
Secondary features (minor criteria)
Diameter >= 7mm
Inflammation
Oozing or bleeding
Altered sensation
Pellagra? px?
nicotinic acid (niacin) deficiency. (B3)
dermatitis, diarrhoea and dementia.depression
may occur as a consequence of isoniazid therapy
Periorificial dermatitis? cause? tx?
cause: Topical corticosteroids, and to a lesser extent, inhaled corticosteroids
clustered erythematous papules, papulovesicles and papulopustules
Management
steroids may worsen symptoms
should be treated with topical or oral antibiotics
Pityriasis rosea features
acute, self-limiting rash- disappears after 6-12 weeks
herpes hominis virus 7 (HHV-7)
no prodrome, but a minority may give a history of a recent viral infection
herald patch (usually on trunk) -> erythematous, oval, scaly patches; distribution parallel to the line of Langer -‘fir-tree’ appearance
Pityriasis versicolor features, mx
also called tinea versicolor,
Malassezia furfur
patches may be hypopigmented, pink or brown (hence versicolor).
Management
- ketoconazole shampoo topical
- if failure to respond, consider alternative diagnoses (e.g. send scrapings to confirm the diagnosis) + oral itraconazole
factors which may exacerbate psoriasis?
BLANQ = white in french; white plaques of psoriasis
beta blocker
lithium
alcohol, ACE Is
nsaids
quines (antimalarials -> chloroquine and hydroxychloroquine)
Streptococcal infection may trigger guttate psoriasis.
trauma
Psoriasis mx
Plaque!!
1st: potent corticosteroid applied once daily plus vitamin D analogue
for up to 4 weeks as initial treatment
2nd: if no improvement after 8 weeks - if no improvement after 8 weeks t
3rd - if no improvement after 8-12 weeks
- potent corticosteroid applied twice daily for up to 4 weeks
- OR coal tar preparation
short-acting dithranol can also be used
secondary care
- Phototherapy
- Systemic therapy: oral methotrexate, ciclosporin, retinoids, biologics
Scalp !!
- potent topical corticosteroids used once daily for 4 weeks
Face, flexural and genital !!
- mild or moderate potency corticosteroid applied once or twice daily for a maximum of 2 weeks
IMPORTANT
- 4-week break before starting another course of topical corticosteroids
- potent corticosteroids for no longer than 8 weeks
- Vitamin D analogues (calcipotriol), unlike corticosteroids they may be used long-term
- should be avoided in pregnancy
Pyoderma gangrenosum tx
oral steroids as first-line treatment
Isotretinoin SEs
teratogenicity - two forms of contraception
dry skin, eyes and lips/mouth (most common)
low mood
raised triglycerides
hair thinning
intracranial hypertension
acne Rosacea mx
simple measures- sunscreen, camouflage
predominant erythema/flushing, limited telangiectasia - topical brimonidine gel (alpha agonist)
mild-to-moderate papules and/or pustules
- topical ivermectin is first-line
- topical metronidazole or topical azelaic acid
moderate-to-severe papules and/or pustules
- combination of topical ivermectin + oral doxycycline
Referral for no improvement, rhinopehyma
- laser therapy
Scabies mx
mite Sarcoptes scabiei
permethrin 5% is first-line- to all areas, including the face and scalp
malathion 0.5% is second-line
all household and close physical contacts should be treated at the same time, even if asymptomatic
Crusted (Norwegian) scabies- Ivermectin
Seborrhoeic dermatitis associated conditions
otitis externa and blepharitis may develop
HIV
Parkinson’s disease
Seborrhoeic dermatitis mx
Scalp
1st. ketoconazole 2% shampoo
2nd. over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’)
selenium sulphide and topical corticosteroid may also be useful
Face and body management
- topical antifungals: e.g. ketoconazole
- topical steroids: best used for short periods
Shingles mx
diagnosis is usually clinical
remind patients they are potentially infectious until the vesicles have crusted over, usually 5-7 days following onset
- avoid pregnant women and the immunosuppressed
- cover lesions
Analgesia
- 1st. paracetamol and NSAIDs are first-line
- 2nd. neuropathic agents (e.g. amitriptyline)
- oral corticosteroids maybe - first 2 weeks in immunocompetent adults wlocalized shingles if the pain is severe and not responding to the above treatments
Antivirals
- within 72 hours for the majority of patients (reduced incidence of post-herpetic neuralgia)
Skin manifestations of systemic lupus erythematosus (SLE)
photosensitive ‘butterfly’ rash
discoid lupus
alopecia
livedo reticularis: net-like rash
Spider naevi v telangiectasia
Spider naevi fill from the centre, telangiectasia from the edge .
Stevens-Johnson syndrome causes
penicillin
sulphonamides!!
lamotrigine, carbamazepine, phenytoin
allopurinol
NSAIDs
oral contraceptive pill
( target lesions, vesicles or bullae, Nikolsky sign, mucosal involvement)
Tinea types & mx
dermatophyte fungal infections
Tinea capitis (scalp ringworm)
- most common cause is Trichophyton tonsurans
- management (based on CKS guidelines): oral antifungals: terbinafine for Trichophyton tonsurans. griseofulvin for Microsporum infections. & ketoconazole shampoo
Tinea corporis (ringworm) trunk, legs or arms
- Trichophyton rubrum and Trichophyton verrucosum
- oral fluconazole
Tinea pedis (athlete’s foot)
Urticaria mx
non-sedating antihistamines (e.g. loratadine or cetirizine) are first-line - 6 wks
a sedating antihistamine (e.g. chlorphenamine) - night time maybe
prednisolone is used for severe or resistant episodes
Vasculitides
types
Large vessel
- temporal arteritis
- Takayasu’s arteritis
Medium vessel
- polyarteritis nodosa
- Kawasaki disease
Small vessel
ANCA-associated vasculitides
- granulomatosis with polyangiitis (Wegener’s granulomatosis)
- eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
- microscopic polyangiitis
immune complex small-vessel vasculitis
- Henoch-Schonlein purpura
- Goodpasture’s syndrome (anti-glomerular basement membrane disease)
- cryoglobulinaemic vasculitis
- hypocomplementemic urticarial vasculitis (anti-C1q vasculitis)
