Dermatology Flashcards
features of eczema
defects in the skin barrier lead to inflammation
- redness
- itch
- dry
- FHx
- flexor surfaces common (cheeks in children)
endogenous types of eczema
varicose eczema
seborrheic dermatitis
discoid eczema
atopic eczema
signs of bacterial infection of eczema
management
weeping, pustules, crusts, atopic eczema failing to respond to therapy, rapidly worsening atopic eczema, fever and malaise)
Fucidin H Cream applied topically if milder
Oral Abx such as fluclox if more severe
eczema herpeticum
a viral infection of eczema involving herpes simplex virus 1 or 2
signs:
- areas of rapidly worsening, painful eczema
- clustered blisters consistent with early-stage cold sores
- punched-out erosions
- fever, lethargy or distress.
needs admission and IV aciclovir
treatment widespread bacterial infections originating from the skin
systemic antibiotics that are active against staph aureus and steptococcus e..g flucloxacillin
localised clinical infection of the skin treatment
Topical antibiotics, including those combined with topical corticosteroids
antibiotics to cover staph aureus and strep
flucloxacillin
erythromycin in fluclox allergy/resistance
3 rd line clarithromycin
when are Antiseptics such as triclosan or chlorhexidine used in skin infection
Adjunct therapy for decreasing bacterial load in cases of recurrent infected atopic eczema
complications of eczema herpeticum if untreated
Encephalitis; particularly if on immunosuppressants
Hepatitis
Pneumonitis
what microorgansmism are resident on the skin
mainly gram positive cocci which are aerobic
- staph aureus
- staph epidermis
- strep species
some anaerobic gram positive bacilli
main gene involved in eczema
fillagrin gene - loss of function mutations strongly linked to eczema
pathology of eczema
breakdown in skin barrier function and inflammation primarily involving Th2 helper cells
emollient regime
for eczema; emollient moisturiser, shower gel, bath additive
emollient regimes reduce the need for topical steroids
topical corticosteroids in eczema
steroids are second line treatment in atopic eczema not controlled by emollient regime
potency should align with severity i.e. mild potency for mild eczema and increase with severity
shouldn’t be used for longer than 14 days for flares
only mild potency to be used on the face
applied once or twice a day
topical calcineurin inhibitors
Tacrolimus and Pimecrolimus are used in eczema as they suppress T-lymphocyte responses, thereby suppressing the synthesis of pro-inflammatory cytokines
used second line after emollients where steroids are wished to be avoided or try after steroids
only in moderate or severe eczema and over 2 years old
side-effect of burning/stinging sensation on initial application
stepwise treatment of eczema
- topical emollient regime
- topical corticosteroids / immune modulators
- phototherapy
- systemic treatments e..g azathioprine, cyclosporin
- biologic drugs e.g. Dupilumab (injection) and other oral agents which are JAK1 and JAK2 inhibitors
macules
flat lesions <5mm
papules
raised bumps <1cm
pustules
pus filled lesions less than 5mm
vesicles
fluid filled lesions less than 5mm
plaques
raised lesions greater than 1cm in size
features of psoriatic nails
pitting
onychylosis
subungal hyperkeratosis
periungal erythema
types of psoriasis
Generalsied pustular psoriasis
Chronic plaque psoriasis
Erythrodermic psoriasis
Guttate psoriasis
Flexural psoriasis
guttate psoriasis
small pink plaques of psoriasis seen on the trunk, often after a streptococcal sore throat
about 1/3 go on to have chronic plaque psoriasis
flexural psoriasis
psoriasis affecting the genitalia or axillae
Usually the appearance is red (erythematous) and slightly shiny, but there will still be a clearly defined edge between normal and affected skin
erythrodermic psoriasis
flare up/inflammation of psoriasis
When it covers over 90% of the body surface it is described as erythroderma. The skin is red, feels hot and even painful.
There may no longer be clearly defined plaques. Patients can feel unwell and become hypotensive. These patients should be admitted to hospital for treatment.
chronic plaque psoriasis
40% of presentations
typical distribution:
elbows and knees
nails
scalp
genitalia and natal cleft
Generalised Pustular Psoriasis
psoriasis can flare, become red, hot, painful and develop pustules within the plaques
emergency requiring hospital admission. The trigger is often WITHDRAWAL of use of a superpotent topical or systemic corticosteroids
psoriatic arthropathy
Between 5- 20% of patients with psoriasis have arthropathy affecting their joints. Arthropathy can precede (50%) or post-date (15%) the development of skin lesions. The patterns of arthropathy fall into five subtypes:
-distal interphalangeal alone
-symmetrical polyarthritis (commonest)
-asymmetrical oligoarthritis
-arthritis mutilans
-spondyloarthropathy
triggers/risk factors for psoriasis
family history
psychological stress
medications; antimalarial, NSAIDs, beta blockers, lithium
alcohol
management of psoriasis stepwise
emollients for all + reduce alcohol and smoking and lose weight
1st line: a potent corticosteroid applied once daily plus vitamin D analogue applied once daily (applied different times of day)
2nd line: if no improvement after 8 weeks a vitamin D analogue twice daily
3rd line: a potent corticosteroid applied twice daily for up to 4 weeks, or
a coal tar preparation applied once or twice daily
short-acting dithranol can also be used
phototherapy and systemic therapy can be considered by secondary care
biologics last step
cells involved in pathogenesis of psoriasis
Th1 cells
increased rate of keratinocyte proliferation
inflammatory angiogenesis
TNF-a and Psors genes also involved
tool to determine severity of skin disease
DLQI (Dermatology of Life Index) is a subjective assessment of the impact of the disease on the patient’s life. The DLQI questionnaire is completed by the patient and is calculated by summing the score of each question resulting in a score between 0 – 30
tool to assess psoriasis severity
PASI (Psoriasis Area Severity Index) is an objective measure of the disease severity and is completed by the clinician. It is a numerical score with 0=no disease and 72=maximum disease
often used to objectively monitor patients
how does phototherapy work for psoriasis
narrow-band UVB or PUVA which slows down the excessive growth of keratinocytes and is considered to be partially immunosuppressive
given 2-3 times a week for 10 weeks
systemic agents that can be used in psoriasis
ciclosporin
methotrexate
Acitretin (oral retinoid)
Fumaric acid esters
Apremilast
biologics used in dermatology
TNF inhibitors
IL-12/23 inhibitors
IL-17 inhibitors
acne vulgaris
Acne vulgaris is an inflammatory condition where lesions develop from the sebaceous glands around hair follicles on the skin of the face, chest , back and anogenital region
what are open comedones
blackheads
APSEA scale
validated tool used to assess psychological impact of acne on work, personal life, relationships confidence etc.
grading clinical severity of acne
The Leeds Scoring system counts and categorises lesions into inflammatory and non-inflammatory ranging from 0 for mild acne to 12 for the severest form (nodules, cysts, scars
indications for treatment with oral retinoids (isotretoin) for acne
- Moderate acne, unresponsive to conventional therapy or relapsing after conventional therapy
- Severe acne
- Acne scarring
- Psychological effects resulting from acne and scarring
- Unusual form of acne
different types of drugs for acne (how they work)
drugs that inhibit sebaceous gland function
- anti-androgens
- oestrogens
- isotretinion
drugs that normalise pattern of follicular keratinisation
- topical retinoids
drugs with anti-inflammatory/anti-bacterial effects
- antibiotics
- benzoyl peroxide
acne pathophysiology
blockage and inflammation of the pilosebaceous unit (the hair follicle, hair shaft and sebaceous gland). It presents with lesions which can be non-inflammatory (comedones), inflammatory (papules, pustules and nodules) or a mixture of both.
treatment of acne
first line 12 week course of one of:
- topical adapalene with topical benzoyl peroxide
- topical tretinoin with topical clindamycin
- topical benzoyl peroxide with topical clindamycin
if moderate to severe consider oral antibiotics and Topical azelaic acid as other first line options
single antibitoic should be used for 12 weeks to assess response
combined oral contraceptives may be considered in women as treatment
what is acne fulminans
Acne fulminans is a sudden severe inflammatory reaction that precipitates deep ulcerations and erosions, sometimes with systemic effects (such as fever and arthralgia).
risk factors for BCC compared to SCC
both
- chronic UV exposure
- skin types I and II
- chemicals
- immunosuppressants
SCC also cigarette smoking and chronic ulcers
Fitzpatrick skin types
Type I - always burns never tans very pale
Type II - usually burns tans poorly pale
Type III - tans after initial burn darker white
Type IV - tans easily burns minimally light brown
Type V - tans darker brown skin
Type VI - always tans darker never burns dark brown/black skin
squamous cell carcinoma
- what is it
- does it spread?
malignant tumour arising from keratinocytes of the epidermis
can invade locally and has metastatic potential
how does an SCC present
fast growing and can be painful
often on face, scalp and hands
rare under 60 years unless immunosuppressed
indurated nodular lesions often have crusted or hyperkeratotic surfaces
can develop de novo or from precursor leisons
pathophysiology of SCC
malignant transformation of normal keratinocytes by apoptotic resistance via loss of TP53
what lesions can be precursors to SCC
actinic/solar keratoses - multiple lesions often head and neck non painful. dysplastic keratinocytes
Bowen’s disease - single plaque of epidermal dysplasia. can be managed with cryotherapy
poor prognostic features SCC
tumours >2cm
lesions on lip or ear
immunosuppression
what options may be used to manage a BCC
- imiquimod cream 5%
- radiotherapy
- photodynamic therapy
- surgical excision; can be done as a day case
- watchful waiting
how can actinic keratosis be managed
5% 5-FU (efudix) cream
how is prognosis of SCC determined
depth invasion of the skin
high risk BCCs
lesions on eyelid margins, ear, lip
perineurial invasion on histology
recurrent lesion
lesions in immunocompromised
BCC presentation
slow growing
typical features; telangiectasia, pearly translucent nodule
types of moles
junctional naevus - brown and flat
intradermal naevus - skin coloured and raised
compound naevus - brown and raised
what are the criteria for 2WW referral
- new mole quickly growing in an adult
- long standing mole changing in shape and colour
- a mole with 3 or more colours or lost its symmetry
- any new nodule growing and pigmented or vascular
- new pigmented line in a nail or something growing under the nail
looking for evidence of metastasis in melanoma
localised: cutaneous/subcutaneous nodules around the lesions
regional: lymphadenopathy
distant: hepatomegaly +/- splenomegaly
treatment of suspected melanoma
excision with a margin of normal skin
same day or same week
after excision follow up 3 monthly for a year
immune and targeted therapies are also now used improving survival
melanoma presentation
50% from existing moles
normally asymptomatic but occasionally bleeding and itching reported
existing or new mole than changes rapidly, irregular, different shades, larger, reddish outline
what are dysplastic naevi
moles that are on a continuum from benign naves to melanoma
some people have several in a genetic condition and this predisposes to melanoma
types of melanomas
superficial spreading
nodular
lentigo maligna
aural lentiginous melanoma
risk factors melanoma
UV exposure +++
sunburns
people with many typical moles
immunosuppression
family history
link to IBD
what is Breslow thickness
distance in mm from the granular layer in the epidermis to the deepest level of invasion
major prognostic indicator
TNM based on this + some other features (mitotic index, ulceration, LN involvement and metastasis)
chronic pruritus
chronic pruritus is > 6 weeks which can lead to characteristic skin lesions including excoriations, lichenification and hyperpigmentation pr hypopigmentation
itching without skin change/rash (pruritus)
unlikely to be dermatological if itch came first
- malignancy and haematological (NHL, leukaemia, metastasis of solid tumours)
- multisystem inflammatory (dermatomyositis, scleroderma) or infectious (HIV, Hep C)
- psychogenic
- metabolic (hyperT, CKD, diabetes)
- GI cholestasis
- drugs
bullous pemphigoid
autoimmune condition causing sub-epidermal blistering of the skin
oral corticosteroids are mainstay of treatment
contact dermatitis
two main types:
- irritant contact dermatitis
- allergic contact dermatitis; type IV hypersensitivity reaction. needs topical potent steroid
Dermatitis herpetiformis
autoimmune blistering skin disorder associated with coeliac disease caused by deposition if IgA in the dermis
Erythema multiforme
hypersensitivity reaction that is most commonly triggered by viruses but also bacteria and drugs
in its most severe form can involve mucosa such as mouth
erythema nodosum
inflammation of subcutaneous fat causing tender, erythematous, nodular lesions usually on the shins
many causes including infection, sarcoid, malignancy, drugs and pregnancy
lichen planus
itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of arms
oral involvement in 50%
needs potent topical steroids
Lichen sclerosus
condition of white patches typically affecting the genitalia of elderly females
managed with topical steroids and emollients
note increased risk of vulval cancer
examples of topical steroids and potency
Mild: Hydrocortisone 0.5%, 1% and 2.5%
Moderate: Eumovate (clobetasone butyrate 0.05%)
Potent: Betnovate (betamethasone 0.1%)
Very potent: Dermovate (clobetasol propionate 0.05%)
psoriasis Treatment options
Topical steroids
Topical vitamin D analogues (calcipotriol)
Topical dithranol
Topical calcineurin inhibitors (tacrolimus) are usually only used in adults
Phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
isotretinoin side effects
teratogenic - need effective contraception
Dry skin and lips
Photosensitivity of the skin to sunlight
Depression, anxiety, aggression and suicidal ideation. Patients should be screened for mental health issues prior to starting treatment.
Rarely Stevens-Johnson syndrome and toxic epidermal necrolysis
scabies presentation and treatment
incredibly itchy small red spots, possibly with track marks where the mites have burrowed. The classic location of the rash is between the finger webs, but it can spread to the whole body.
treatment is with permethrin cream which should be left on for 8-12 hours all over for
Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)
spectrum of the same pathology of epidermal necrosis due to an immune response
caused by medications or infections
needs admission, good supportive care as well as medical management including steroids, immunoglobulins and immunosuppressant
can lead to eye damage, permanent skin damage and secondary infection
