derm2 Flashcards
haematological findings of SLE?
haemolytic anemia
thrombocytopenia
leukopenia
antibodies in SLE?
ANA
anti-dsDNA
anti-Sm
anti-phospjolipid
derm fidnings in SLE?
photodistributed rash
chillblains
livedo reticularis
alopecia
how does SCLE present?
widespread photosensitive rash
baby has annular plaques. diagnosis? next tests?
neonatal lupus - Ro positive
do ecg as risk of heart block
pt presents with gottrons papule, heliotrope rash, ragged cuticles, and shawl sign. dx? antibody?
dermatomyositis
anti-Jo1
pt has dermatomyositis and interstitial lung disease - antibody? other symptoms?
anti-MDA5
digital ulcers/iscahemia
antibody associated with dermatomyositis and malignancy?
anti-p155
what levels are high with dermatomyositis?
CK
ALT
test done for IgA vasculitis?
biopsy for direct immunofluorence - perivascular IgA
patient has erythema nodosum and lupus pernio with a dry cough? likely diagnosis? histology?
sarcoidosis
LP = purplish rash on face
non-caseating epitheloid granulomas
exclude infection
DRESS diagnostic criteria?
drug reaction with eosinophilia and systemic symptoms fever ≥38.5 lymphadenopathy ≥2 hypereosinophilia internal organs involvement ≥50↓ BSA erythema facial odema
organ most commonly involved with DRESS?
liver
onset for DRESS?
2-6wks after drugs
name 4 drugs associated with DRESS?
ibuprofen
allopurinol
anti-epileptics
amoxicillin
first line tx for DRESS?
corticosteroids
pt recently had an allogenic stem cell transplant for AML and is presenting with erythematous rash covering ≥60↓ BSA and diarrhoea. they’ve also been put-on new drugs. Dx? other symptoms?
graft versus host disease
scleral icterus
diarrhoea and facial & acral rash make gvhd more likely than DRESS
pathogenesis of gvhd?
donor derived t lymphocyte activity against antigen sin inmmunocompromised recipient
causes of pruritus without a rash?
lymphoma, polycythaemia uraemia cholestasis iron excess/deficit HIV Hep ABC cancer drugs psychogenic old age
what can pruritus without a rash lead to?
nodular prurigo
pt presents with bleeding gums, corkscrew hairs and petechiae. Upon asking most of their meals are takeout. dx? other symptoms?
scurvy
spongy gingivae
follicular hyperkeratosis
perifollicular haemorrhage
pt presents with inflamed lips, desquamation of large areas of their skin and diarrhoea. upon examination they have. hepatomegaly. what are they deficient in? other symptoms?
kwashiorkor - protein deficiency cachexia oedema failure to thrive cheilitis = inflammation of lips soft nails, dry hair
what triad is presenting zinc deficiency?
dermatitis, diarrhoea, depression
pt presents with ‘Casals necklace’ rash and painful fissures on their palms and soles. what are they deficient in? other sx?
vitamin b3 niacin
dermatitis, diarrhoea, dementia, death
photodistributed erythema
perianal, perioral and genital inflammation
pathogenies of carcinoid syndrome and symptoms?
due to metastases of a malignant carcinoid tumour → serotonin secretion
flushing, diarrhoea, bronchospasm, hypotension
symptoms of Stevens-Johnson syndrome/toxic epidermal necrolysis?
prodrome - flu like symptoms
lesions on trunk ≥ limbs/face
macule, blisters, erythema - targetoid
blisters merge and detach in karge sheets
how to differentiate between SJS/TEN?
SJS | SJS/TEN | TEN
BSA detachment ≤10 | 10-30 | ≥30
mortality ≤10| |≥30
causes of SJS?TEN?
abx - beta-lactams/sulphonamides
allopurinol
anti-epileptics
nsaids
pathogenesis of SJS/TEN?
cell-mediated cytotoxic reaction against epidermal cells
3 ddx for SJS/TEN?
SSS
thermal burns
cutaneous gvhd
what can be used to assess severity of sjs/ten?
SCORTEN age≥40 epidermal attachment % serum urea glucose bicarb malignancy
complications of sjs/ten?
death blindness dehyrdration hypo/hyperthermia renal tubular necrosis liver and heart failure
pt has a rash covering more than 90↓ of their BSA. they have a hx of atopic eczema and have recently started some new meds. dx? other sx?
erythroderma
cause - eczema, psoriasis, drugs, sezary syndrome
edema, tachycardia, risk of sepsis, dehydration
how to treat erythroderma?
treat underlying cause
restore fluids, electrolytes, circulation and body temp
emollients
± steroids and abx
derm presentations of ckd?
anaemia → mucous pallor and hair thinning excoriations prurigo calciphylaxis half half nails xerosis - dryness
what derm disease can lead to ckd?
anca associated vasculitis / sle
derm presentations of cld?
excoriations prurigo muehrckes lines on nails terry's nails palmar erythema spider telangiectasia clubbing jaundice porphyria cutanea tarda
pt with DM presents with plaques that have a red-brown raised edge and a yellow brown centre. dx? tx?
necrobiosis lipoidica
topical /intralesional steroids
derm presentations of DM?
necrobiosis lipoidica Terrys nails xerosis granuloma annulare xanthelesma/xanthomata neuropathic ulcers acanthosis nigricans
2 common derm presentations in acromegaly?
cutis gyrata verticis
acne
derm presentations of hiv?
morbilliform rash uticaria pruritus erythema multiforme oral/genital ulceration
derm presentations of ibd?
pyoderma gangrenosum orofacial granulomatosis erythema nodosum (panniculitis) aphthous ulceration psoriasis/pemphigoid
derm presentations of celiac disease?
dermatitis herpetiformis
what is hidradenitis suppurativa?
inflamed nodes, sterile abcess, sinus tracts, fistula, hypertrophic scars
affects axillary, anogenital & inframmary areas mostly
what diseases is pyoderma gangrenous associated with?
IBD
leukeamia
seronegative arthritis
skin diseases associated with malignancy?
dermatomyositis
pyoderma gangrenosum
erythema gyratum repens
paraneoplastic pemphigus
(urticaria, vasculitis, prurutis)
haemaorhagic docules can indicate what?
metastatic pancreatic carcinoma
mucosal melanosis can indicate what?
peutz-jegher syndrome
name 3 virulence factors that staph aureus has?
haemolysin
leukocidin
exfoliative toxin
virulence factors of strep pyogenes?
m protein → anti-phagocytic
HA capsule
erythrogenic exotoxins
streptolysins S & O
what kind of folliculitis is assoicted w HIV?
eosinophilic
recurrent cases of folliculitis is assoicted with what?
tx?
nasal Staph aureus
expressing panton-Valentin leukocidin
abx - flucloxacillin and erythromycin
furunculosis → incision and drainage
furuncle vs carbuncle?
furuncle = deep follicular abscess
carbuncle = connected adjacent furuncles
carbuncle more likely to lead to speticaemia and cellulitis
risk factors for developing recurrent furnucles or staphylococcal impetigo?
immune defijency : AIDS hypogammaglobulinaemia hyper IgE sybdrome DM
pathogenies of panton Valentin leukocidin staph aureus?
B pore forming exotoxin
leukocyte destruction and tissue necrosis
cutaneous and extracuytaneous signs of panton Valentin leukocidin staph aureus?
cutaneous:
recurrent painful abscesses
folliculitis
cellulitis
extra:
necrotising pneumonia
necrotising fasciitis
purpura fulminan
risk factors for PVL staph aureus?
5 Cs close contact contaminated items crowding (un)cleanliness cuts and grazes
PVL staph aureus management?
abx - tetracycline
chlorhexiidne body wash
nasal mupirocin ointment
treat close contacts
skin condition associated with hot tubs, swimming pools etc?
pseudomonal folliculitis
symptoms and mx of pseudomonal folliculitis?
diffuse truncal eruption of follicular erythematous papule
normally no tx
severe/recvurrent → oral ciprofloxacin
commonest causes of cellulitis?
strep pyogenes
staph aureus
what is cellulitis
infection of lower debris and subcutaneous tissue
tender swelling ill defined blanching erythema
2 types of impetigo?
non-bullous - strep
bulbous - staph → exfoliative toxins a&b → splint epidermis by targeting desmoglein 1
severe form of streptococcal impetigo?
ecthyma
punch out ulceration with erythema and thick crust
risk factor for SSSS?
neonates/infants
immunocompromised adults
pathogenesis of SSSS?
infection at distant site eg conjunctivitis → exfoliative toxin → cannot be removed quickly enough by kidneys → diffuse tender erythema → flaccid bullae → wrinkling and exfoliate → oozing erythematous base
what organism causes TSS?
group a staph aureus → pyrogenic exotoxin TSST-1
symptoms of TSS?
fever hypotension diffuse erythema thrombocytopenia desquamation post erythema gI muscular CNS renal hepatic involvement
pt has well demarcated brown scaly patches in their intertriginous areas. dx?
erythrasma
(corynebacterium)
pt has pitted erosions on their soles. dx? cause? mx?
pitted keratosis
corynebacterium
clindamycin
pt presents with a red swollen hand that has slowly been spreading. he is a fishmonger. dx?
erysipeloid
rf = raw contaminated fish and meat
pt presents with a painless necrotic ulcer on his finger. it looks swollen. he is a sheep farmer. dx? what would you find on lymph node exam?
anthrax (bacillus anthracis)
regional lymphadenopathy and pain
child presents with a tender superificla bullae on the volar fat pad of their finger. dx? causes?
blistering distal dactylitis
strep pyogenes / staph aureus
erysipelas causes? signs and symptoms? mx?
infection of deep dermis and subcutis
b haemolytic streptococci / staph aureus
prodrome - malaise fever headache
erythematous indurated plaque w cliff drop edge ± blistering
red streak on face/ limbs → lymphangitis
find portal of entry
IV abx
scarlet fever causes? prodrome? skin sx?
URTI - erythoegnic toxin strep pyogenes
sore throat, headache, fever malaise, anorexia
blanching tiny pink spots on chest neck axillae → whole. body → sandpaper like texture
complications of scarlet fever?
otitis sinusitis pneemonia myocarditis heaptitis meningitis rheumatic fevre glomerulonephritis
presentation of necrotising fasciits? mx?
dusky induration → rapid painful necrosis of skin connective tissue and muscle
broad spectrum parenteral abx and surgical debridement
±mri
necrotising fasciitis of the scortum?
fournies gangrene
initial presentation of Lyme disease? other name? progression?
borreliosis erythema migrans → annular erythema multiple smaller secondary lesions neuroborreliosis → facial palsy, aseptic meningitis arthritis carditis
what’s required for diagnosis of borreliosis?
high index of suspicion
serology not sensitive and histopathology is non-specific
pt presents with a ulcerated lesion that is panful and they have painful regional lymopahdenopathy as well as fear headache and malaise. they mention they were recently bitten by a rodent (they work at the zoo). dx? causes?
ulceroglandualr form of tularaemia
francisella tularensis
presentation of ecythma gangrenosum?cause?
red macule → oedematous → haemorhaggic bullae → ± ulcerate ? form an eschar
neutropenic pts
pseudomonas aeruginosa
difference between ectyhma and ecthyma gangrenosum?
ecthyma → streptococcal infection
EG → pseudomonas aeruginosa
primary syphillis presentation?
chancre - painless ulcer with firm indurated border
1 week later → painless regional lympoahdenopahty
presentation of secondary syphilis?
~50n days post chnacre fever, malise, pruritius, irritis rash alopecia mucous patches lymphadenopathy hepatosplenomegaly condylomata lata
rare manifestation of secondary syphilis?
lues maligna - pleomorphic skin lesions
presentation of tertiary syphilis?
summa skin lesions
destroyed nasal cartilage
CVD
neurosyphilis
treatment of syphilis?
IM benzylpenecillin
orał tetracycline
2 types of leprosy and the difference?
lepromatous - multiple lesions , sensation and sweeting normal
tuberculoid - solitary/few lesions, annular, hairless, anhydrotic, numb
3 ways cutaneous TB can be acquired?
exogenously
contagious endogenous spread
haematogenous/lymphatic endogenous spread
investigations for cutaneous TB?
interferon gamma release assay
histology ZN stain
culture / PCR
cutaneous manifestations of TB?
tuberculous chnacre TB verrucosa cutis scrofuloderma orificial TB - nasal lupus vulgaris military TB tuberculous gumma
risk factors for molluscum contagiosum? mx?
children
immunocmpromiised
curettage, imiquimod, cidofovir
2 ddx for molluscum contagiosum?
basal cell caricoma
pyogenic granuloma
2 types of HSV?
HSV-1 - direct contact w contaminated saliva / secretiions
HSV-2 - sexual contact
symptoms of HSV?
recurrent vesicular eruptions favouring orolabial and genital regions
tender lymphadenopathy , malaise
ulceration, pustules, erosions w scalloped border
urinary retention → genital lesions v painful
aseptic meningitis
what can cause reactivation of HSV?
UV stress spontaneous fever local tissue damage
emergency finding in HSV?
eczema herpeticum → can lead to encephalitis
monomorphic punched out erosions
common presentation of HSV in children? misdiagnosis?
herpetic whitlow
more common in HSV1
pain, swelling and vesicles on digits
misdiagnosed as paronychia or dactylitis
common presentation of HSV in wrestlers?
herpes gladiatorium
HSV1 - athletes lesions come into contact with one another
cause of neonatal HSV?prresnattion? mx?
exposed during vaginal delivery especially if mother got hsv close to delivery time
onset between birth and 2 weeks
vesicles → bullae erosions
encephalitis → neurological deficits without treatment
IV antivirals
risk factors severe/chronic HSV? presentation?
immunocompromised patients eg HIV/tx
chronic enlarging ulceration at multiplemsites ±resp/GI tract
diagnosis and mx of HSV?
swab for pcr
oral acyclovir (or valacyclovir) 200mg 5xday in immunocompetent localised infection
or IV 10mg/kg TDS 7-19 days
what virus presents in a dermatomal way?
varicella zoster virus
causes of hand foot and mouth disease? difference?
coxsackie A16
enterovirus 71 - higher incidence of neurological involvement eg encephalitis
spread by oral oral route or oral faecal route
presentattion of hand foot and mouth disease?
prodrome - fever, malaise, sore throat
red macules, vesicles and ulcers on buccal mucosa, tongue, palate, pharynx ± hands and feet
what causes morbilliform eruptions?
measles rubella ebv cmv HHV6&7
leptospirosis
rickettsia
causes of petechiae/purpura?
coagulation abnormailites - ITP, DIC vsculitis infections TEN raynauds HEPb, CMV, rubella
what is gianotti-crosti syndrome? causes?
acrodermatitis of childhood (1-3yrs)
acute symmetrical erythematous papular eruption on face, extremities and buttocks
EBV, CMV, HHv6, coxsackie, hep B
pt presents with a slapped cheek rash and a reticulated rash on chest and thighs. dx? causes?
erythema infectiosum
parvovirus b19
child presents with a fever that’s lasted for 4 days and has now got small pink papule on their trunk and head. dx? causes?
roseola infants (6th disease) HHV6 and HHV7
goat farmer presents with dome shaped, firm bullae on hands and forearms. dx? cause? mx?
orf
parapoxvirus
self resolving in 4-6 weeks
teenager presents hypopigmentation, an erythematous macular eruptoion and some fine scales. They mention it gets wraps in the summer. dx? mx?
pityriasis versicolor (superficial fungal) topical azalea
what is kerion?
inflammatory fungal infection → abscess of the scalp & posterior cervical lymphadenopathy
± secondary infection w staph aureus
commonest cause of tinea capitis?
trichophyton tonsurans
what are dermatophytes/
fungi that live on keratin
causes of tinea pedis? (superficial fungal)
tricophyton rubrum → hyperkeratosis
tricophyton mentagrophytes → vesiculobullous
what is the id reaction?
inflammatory reaction distant from the site of a dermatophyte infection
urticaria, hand dermatitis, erythema nodosum
what is a majocchi granuloma?
follicular abscess when dermatophyte infection penetrates follicular wall into surrounding dermis
risk factors for candidiasis?
occlusion, moisture, warm temp, DM
presentation of candidiasis?
superficial fungal
erythema oedema , thin purulent discharge
intertriginous / oral mucosa
cause of valvovaginitis
risk factors for aspergillosis?
neutropenia
corticosteroid therapy
presentations of aspergillosis?
well circumscribed papule with necrotic bases and surrounding erythema
can invade blood vessels → thrombosis and infarction
can extend into bone, cartilage and fascia
disease similar to aspergillosis?
fusarium
presentation of mucormycosis? mx?
fever, headache, facial oedema, exophthalmus, orbital cellulitis, cranial nerve dysfunction
aggressive debridement
antifungal therapy §
risk factors for mucormycosis?
DM esp w DKA malnutrition uraemia neutropenia steroids /abx burns hiv
presentations of scabies?
red to flesh coloured pruritic papules
interdigital areas, wrists, genitals, axillae
burrow of fine white scale - diagnostic
hyperkeratosis in Norwegian scabies
tx for scabies?
permethrin
oral ivermectin
2 cycles
lice treteamnts?
permethrin
oral ivermectin
malathion
body Louse prrsenation?
pruritic papules and hyperpigmentation
presentation of bedbugs? tx?
itchy weals around a central punctum
treatment only if symptomatic , fumigation of home
what is a melanoma?
malignant tumour from melanocytes
can be found on mucosal surfaces and uveal tract
leading cause of skin cancer deaths
rfs for melanoma?
family hx, MC1R variants light skin red hair sun exposure immunosuppresiion ≥100/atypical malanocytic nevi
broad pathogenesis of melanomas?
AMPK pathway activated KIT mutations - acral and mucosal NRAS gene BRAF gene - intermittent UV exposure CDKN2A mutations → AMPK & P16 (tumor suppressor)
immunotherapy for melanoma? indications?
CTLA-4 blockade - ipilimumab (natural inhibitor of T cell activation) (BRAF negative)
PDL1 inhibitors eg nivolumab
BRAF & MEK inhibitor for mutated oncogene targeted therapy
if unresectable or metastatic
5 subtypes of melanoma?
superficial spreading **most common nodualr lentigo maligna acral lentiginous unclassifiable
superficial spreading melanoma?
most common in light skinned ppl
men → trunk , women → legs
hypo/depigmentation = host immune system attacking = regression
horizontal growth then vertical
nodular melanoma?
trunk, head, neck
m≥f
usually blue to black nodule
only vertical growth
lentigo maligna melanoma? can progress to?
≥60yrs
chronically sun damaged skin , **face
slow growing, asymmetrical, macular, irregular border, brown/black
invasive lentigo maligna melanoma
acral lentiginous melanoma?
palms, soles, around nails
incidence similar across all racial and ethnic groups
→ represents disproportionate no of melanomas diagnosed in afro-carribenas and asians
self detection for melanomas?
asymmetry border irregularity colour variegation diameter ≥5mm evolving
what is garbe’s rule?
worried patient about lesion → do not ignore → low threshold for performing a biopsy
3 ddx for melanomas?
basal cell carcinoma
sebhorreic keratosis
dermatofibroma
what would indicate poor prognosis for melanoma?
breslow thickness ≥1mm male lymph node involvement ulceration age trunk/head/neck
investigation for melanoma and positive findings?
dermoscopy asymmetry multiple colours reticular/globular starburst
also consider history and rfs
melanoma managemnt?
primary excision down to subcutaneous fat with 2mm peripheral margin
wide excision margin determined by breslow depth
sentinel lymphoma node biopsy for pT1b+
PET-CT and brain MRI for stage 3 and 4
broad tnm staging for melanoma?
T1 ≤1mm
T2 1-2mm
T3 2-4mm
T4 ≥4mm
a - no ulceration
b - ulceration
major prognostic factor for melanoma?
ldh
↑ = worse prognosis
rfs for keratinocyte displasia/carcinoma and types?
pale skin, UV damage
actinic keratoses (dysplasia)
Bowen’s disease (SCC in situ)
squamous cell carinoma (±metastasis)
basal cell carcinoma (no metastasis, locally invasive)
pathogenesis of basal cell carcinoma?
UV radiation
tumour cells and mesenchymal stromal cells
up regulation of PDGF and its receptors
↑↑ metalloproteinases and collagenases → degrade preexisting dermis → tumour cells spread
loss of function in chromosome 8q
p53 mutations
squamous cell carcinoma pathogenesis?
UV radiation
alterations in p53, CDKN2A, NOTCH1/2
most common skin cancer?
basal cell carcinoma
rfs for keratinocyte carcinomas?
PUVA exposure fair skin genetics nevus sebaceous organ tx & immunosuppression ionising radiation
what is actinic keratoses?
limited to epidermis
head, neck, upper extremities
eryhtemaotus macule ± scale → thick papules, hyperkeratosis → ± cutaneous horn
what is Bowens disease?
progression form actinic keratoses or de novo → SCC in situ
erythematous scaly plaque ± slightly elevated
can look like actinic keratoses, psoriasis or eczema
treatment for actinic keratoses and Bowens disease?
5-fluorouracil cream cryotherapy imiquimod cread photodynamic therapy curettage and cautery excision
presentations squamous cell carcinoma?
erythematous to skin coloured papule plaque like exophytic hyperkeratotic ulceration
high risk features of a SCC?
trunk and limbs ≥2cm, head/neck ≥1cm, periorificial
ill defined margins
rapidly growing
immunosuppression
previous radiotherapy or chronic inflammation
poorly differentiated, Clark level 4/5
beyond subcutaneous fat
pernineural, vascular or lymphatic invasion
keratoacanthoma?
pseudomaligancy or variant of SCC
rapid enlarging papule with keratotic core
resolves slowly leaving atrophic core
ix for scc?
clinical diagnosis often sufficient
±diagnostic biopsy
±US of regional lymph nodes
ddx of scc?
bcc
viral wart
merkel cell carcinoma
mx of SCC?
examine rest of skin and regional LNs
excision
radiotherapy if unresectable or high risk eg perineurial invasion
cemiplimab for metastatic SCC
skin monitoring and sun protection advice
6 types of bcc?
nodular **commonest superficial morpheic infiltrative basisquamous micro nodular
nodular BCC presentation?
shiny, pearly nodule/papule
superficial BCC presentation?
well-circumscribed erythematous macule or the
morpheic BCC presentation?
elevated/depressed induration
light pink to white
extensive local destruction
basisquamous BCC presentation?
histological features of BCC and SCC
micro nodular vs nodular BCC presentation?
clinically similar
micro nodular more destructive → high rates of recurrence and subclinical spread
ix for BCC?
often clinical diganosis sufficient
±biopsy
ddx for BCC?
SCC
Merkel cell carcinoma
adnexal carinoma
BCC treatment?
standard surgical excision mohs micrographic surgery -recurrent BCC -agressive eg. micro nodular, invasive, morpheic -critical site bread loafing
5-fluorouracil, imiquimod, photodynamic therapy, curettage, radiotherapy, vismodegib (hedgehog pathway)
cutaneous t-cell lymphoma common subtypes?
sezary syndrome
mycosis fungicides
stages of mycosis fungicides CTCL?
patch (erythematous, fine scales, ±pruritus) → plaque → tumour stage
genes in mycosis fungicides CTCL?
CDKN2A
PTEN
STAT3
examination for MF CTCL?
type and extent of skin lesions
palpable of LNs?
skin biopsies
FBC
treatment of MF CTCL?
plaque/patch stage → topical corticosteroids, photo/radiotherapy
nodal involvement → systemic chemo
brentuximab vedotin
ddx for mycosis fungoides?
psoriasis
eczema
parapsoriasis
sezary CTCL presentation?
triad of erythema, sezary cells and lymphadenopathy
treatment for sezary CTCL?
extracorporeal photophoresis
± adjuvant PUVA & topical corticosteroids
what is kaposi sarcoma?
HHV8
±immunosuppression
pink patches to dark plaques, nodules, polyps
chemo/radiothearpy ≥ surgery
what is Merkel cell carcinoma associated with?
polyomavirus
Merkel cell carinoma presentation?
solitary rapid growing nodule
firm dome shaped
Merkel cell carinoma treatment?
surgery
radiation
anti PDL1 avelumab
anti PD1 pembrolizumab
