derm 2 Flashcards
herpes (shingles)
herpes zoster infection- reactivation of varicellar zoster.
presents with dermatomal pain, eruption of grouped vesicles.
pain preceeds rash, lasts 4-5 weeks.
RF: over 50, female, HIV, chronic sted use, chaemo/ malignency.
Ix: usually a clinical diagnosis
can swab + PCR.
Rx: usually self limiting but consider antiviral in all pts
famciclovir 500mg 8hrly 7/7
OR
valaciclovir 1000mg 8hrly 7/7
2nd- aciclovir 800mg 5DS 7/7
Refer if eye involvement (opthalmologist) - quicker start of antivirals.
headlice (pediculosis capitis)
an obligate ectoparasite that lives on human beings and feeds on human blood
RF: socially active- young children (3-12)
female, close living conditions.
eggs can be visible on hair 1cm from scalp.
Ix/Dx: doscivery of live young or adult louse. usually vis if 6mm from scalp.
on magnification they have dark eyespots.
may see excessive itching
Rx: pediculide- dimeticone topical or permethrin topical.
2nd line mechanical removal (wet combing)
can use petroleum jelly as an occlusive.
impetigo.
Impetigo contagious, blistering skin infection. typically in children.
Staphylococcus aureus and Streptococcus pyogenes.
It has two forms: non-bullous and bullous. Bullae are fluid-filled lesions of >0.5 cm in diameter. single lesions often.
non bullous more common
RF: humidity, poor hygiene, chronic colonisation, prior skin disease
Mx: topical abx— hydrogen peroxide d-tds 3/52.
2’- mupirocin topical
Or fusidic acid.
if widespread, deeper or MRSA give oral.
complications: post strep glomurolonephritis
sepsis, cellulitis, osteomyolitis.
what is a melanocytic naevi
a benign mole
discuss melanoma
malignant tumour arising from melanocites.
most common cancer in young adults.
RF: sun exposure, FH, prev melanoma,
slight predisposition to male. fair skin, sunbed, increacing numbers of naevi, immunosupression. age.
may present as changing, bleeding etc
Ix: ugly duckling sign,
dermoscopy, biopsy- breslow indicator of prognosticity.
Rx: generally 99% cure rate with excision.
margin if confined to epidermis- 0.5-1cm
once 1cm need 2cm margin.
adjuvinant therapy- —pembrolizumab or nivolumab is stage 1-2.
stage 3-4— pembrolizumab + surgery (node etc)
17% get metastatic disease.
abcde assessment for melanoma + staging of melanoma
Asymmetry or lesion
Boarder irregularity, Bleeding
Colour variability
Diameter >6
Evolution – changing.
Breslow thickness
T1 if under 1mm
T2 1-2mm
T3 2-4mm
T4- >4mm + ulce
Add B to staging if an ulcer present.
necrotising fascitis
a severe life threatening skin infection.
bacteria introduced to skin- infection extends through fascia NOT into underlying muscle.
tracks along fascial planes– extends beyond area of cellulitis.
S+S: fever, tachycardia, hypotension– actions of bacterial toxins
severe pain– anaesthesia at site of infection. pedema and erythema- oedema byond erythema.
toxins cause microthrombi- occluding the soft tissue causing the cell death.
high mortality 10-40%.
types of nec fash
type 1 - polymicrobial by anaerobes- clostirium, e coli, klebsiella, proteus, enterobacter.
type 2- monobacterial – strep pyogenes. occ s aureus
other rarer ones- freshwater or saltwater/ oyster eposure etc.
Ix + Rx nec fash
Ix: clinical diagnosis- do not delay surg refferal.
innspection and debridement or-‘finger test’ performed at bedside (no resistance, no bleed, necrotic tissue + dishwater)
cultures is most specific.
Rx: rapid debridement
empirical abx therapy.
reconstructive surgery down the line.
discuss neurofibromatosis type 1
autosomal dominant genetic disorder.
progressive over lifetime.
leads to neuro defecits, motor delay, incoordination, vision/ school problems. gastro problems- very wide ranging and debilitating.
may be subtle if presenting young.
defining features: cafe au lait spots.
multiple neurofibromas
iris lisch nodules
RF: parent with NF-1
severe crush trauma (can lead to local neurofibromas)
Ix: MRI/CT for tumour imaging
PET scan
biopsy
ginetic testing for mutation confirmation
management of NF type 1
pheochromocytoma- (adrenal mass) – surgical removal.
generally surgical removal of tumours if possible.
generally patients die from malignancy
whole tumour removal by amputation is done.
can get additional chaemo.
discuss NF type 2
much more rare than type 1
tumours develop along the nerves- espechially vestibulochchlear
S+S: tinnitus, hearing loss, balance issues – all progressive. hallmark is that it is bilateral.
can get tumours in the brain.
autosomal dominant. can display mosaicism in 1 in 3.
Ix: symptom investigation
genetic testing.
Rx: symptomatically.
discuss eczema
dry itching skin, erythema, scaling, vesicles or lichenification.
can affect all age groups, but most commonly before 5y/o. 10-20% of children.
assoc with other atopic diseases.
RF: filaggerin gene mutation
<5
FH, allergic rhinitis, atopy.
Ix: clinical diagnosis.
consider IgE levels, skin prik testing, elimination diet.
Rx: 1st line- emmolients.
intermittent topical steds (hydrocortison topical 0.2-2%)
consider topical abx or oral abx.
2nd line- systemic immunosuppresive agent- pred, ciclosporin.
in chronic consider a topical cacineurin inhibitor: pimecrolimus or tac.
discuss pemphigus vulgaris
autoimmune condition- causing blistering of skin.
type 2 hypersensitivity. - ab’s against desmosones (1 and 2 proteins)
layers of skin seperate under attack and blisters form.
progresses- lesions enlarge and bahave physicologically like a burn.
mortality 5-15%- deemed potentially fatal.
RF: 50-60, women.
S+S: initially oral blisters. these then spread to other mucous sites + normal skin. spared soles and palms.
Nikolsky sign- (induction of blistering in normal skin) - indicative.
Ix: punch biopsy from site near blister.
Rx:
steds
rituximab
pemphigus vulgaris vs bullous phemphigoid
tombstoning on histology visible on PV.
PV split is between keratinocites and basal layer
BP- split occurs between epidermis and dermis.
psoriasis
systemic immune mediated inflammatory skin disease. may have nail + joint involvement. 75-90% of people have scalp
involvement.
HLA-CW6
chronic plaque psoriasis is most common form. erythrodermic needs admission.
common disease 1.3-2.8% of ppl affected.
S+S: chronic plaque lesions- red, silvery-white scaley, circumscribed. - elbows, knees, extensor surfaces.
multifactoral disease with ginetic basis.
RF: genetic/ FH, infection, local trauma
Ix + Mx of psoriasis + any associated conditions
Ix: clinical diagnosis
biopsy if unsure.
Rx: lifestyle advice.
moisturising emolient
topical steds - hydrocortisone 2.5%. 2-4x a day
2’- tac topical
if severe- add phototherapy, DMARD e.g methotrexate,
add topical vit d if initial not good response.
associated conditions:
cardiovasc
psoriatic arthritis
depression
lymphoma
discuss two of the less common types of psoriasis
guttate- generally triggered by streptococcal infection. children and adolecents most commonly affected.
many small papules. - phototherapy 1st line- then normal rx
pustular- HLA-B27 associated. rare- serious. pustules develop quick on wide area of skin.
may appear every few days or weeks in cycles. Can be triggered- e.g withdrawal of steroids.
may need admission as more severe —-
fluds
either intense topical or
systemic
acitretin 25-50mg orally OD
pyoderma granulosum
an autoinflammatory dermatosis— painful ulcers.
neutrophilic infiltration.
quite rare- and presents same as many things- consider if a non healing ulcer.
S+S: painful non healing ulcer.
exagerrated response after trauma.
pustules–> edore into ulcers–> large necrotic central ulcer. — quite big lesions.
small but significant chance of reocurrence.
Ix: biopsy + culture.
identify inflam bowel, rheumatoid conditions if present
Rx: systemic – ciclosporin, prednisolone.
urgent refferal to specialist.
discuss rosacea (steve disease)
chronic inflam skin condition
affects face convexities
one diagnostic or two major features needed for diagnosis.
D- phymatous changes, persistent erythema
M- flushing erythema, papules, pustules, telangiectasia, eye symptoms.
minor- skin burning/ stinging, dry skin, oedema.
can get ocular rosacea- discomfort, tearing, dryness, itch, photophobia, blurr.
may progress, or may remit and relapse.
unsure of cause.
Rx: topical brimonidine
topical ivermectin. - if papules and pustules
if severe ivermectin + oral doxy 40mg OD.
scabies
an intensley itchy skin infestation caused by sarcoptes scabiei
classical scabies- 1-15 mites per host
crusted (norwegian)- thousands-millions in exfoliating skin. - immunodef, unable to itch.
S+S: itching 3/52 post infestation initially.
erythematous papules- periumbilical, waist, genetalia, breasts, but, axilla, fingers.
RF: close contact
social depravation, institutionization.
winter.
can lead to 2’ cellulitis.
Ix: clinical – skin scrapings can be used.
ink test to check for burrows.
Rx: permethrin 5% cream. of everyone contacts household members, everyone.
GUM refferal for contact tracing if needed.
itch may continue for 4 weeks after rx.
stevens johnson syndrome/ TEN
severe and fatal form of erythema multiforme.
may initially be mild, but progress to bad bad.
less than 10% skin detachment. SJS- TEN greater than 30%. mixed between the 2.
seen in all ages. preference to younger adults/ kids.
male 2:1 female.
abx assoc with >1/4.
Ix: biopsy, culture, FBC, - symptomatic investigation and management.
Rx: consider burn centre/ icu.
withdraw offending drug.
VTE- LMWH
skin management- quite complex.
viral warts
verrucae vulgaris- caused by HPV infection
affects most people in their lifetime- most common in children and young adults.
generally not too bad- but need distinguishing from SCC- key information point immunosuppression.
S+S: elevated, round, kyperkeratotic skin papules. grey/brown. - occur at sights prone to trauma (knees elbows)
RF: water immersion, occupation with meat or fish, nail biting, under 35, immunodef.
Ix: clinical diagnosis.
consider biopsy if sus.
Rx: watch and wait- most go away over time.
1st line- debridement + salicylic acid. (consider duct tape occlusion)
Or
Cryotherapy
OR
silver nitrate.
local immunotherapy (imiquimod) 2nd line.
if immunocomprimised start with debride + salicylic + local immunotherapy.
