(derm) the skin in systemic disease Flashcards
why is the skin important in systemic disease?
recognition of skin signs can lead to diagnosis of underlying systemic disease
- allows recognition of internal malignancy
- prevents or reduced internal organ damage when diagnosed early
what are three ways in which the skin can indicate systemic disease?
1) skin can be targeted in a multi-organs systemic disease (e.g. sarcoidosis)
2) tell-tale skin signs can indicate internal disorder (flushing in Carcinoid syndrome, pyoderma gangrenosum in IBD)
3) systemic disease secondary to skin disorder (e.g. cardiac failure due to erythroderma)
which systemic disease does pyoderma gangrenosum suggest?
inflammatory bowel disease
which blood tests are commonly done in dermatology?
full blood count
renal profile
liver function tests
inflammatory markers
autoimmune serology
which microbiology tests are commonly done in dermatology?
viral/bacterial serology
swabs for bacteria culture & sensitivities, viral PCR
tissue culture/PCR
which specialist tests are commonly done in dermatology?
skin biopsy
imaging
microscopy
what is a punch biopsy?
taking a punch-size piece of skin from the body
when are punch biopsies taken?
to study suspected melanomas, invasive carcinomas, inflammatory lesions and neoplasias
how are punch biopsies studied?
identify inflammatory patterns and cellular abnormalities
to detect autoantibodies in immunofluorescence
skin biopsy, tissue culture
what are the two main types of lupus erythematosus?
systemic lupus erythematosus = SLE
chronic cutaneous (discoid) lupus erythematosus = DLE
define pancytopenia
deficiency of all three cellular components of the blood (red cells, white cells, and platelets)
what are the musculocutaneous findings in lupus erythematosus?
chillblains
photo-distributed (sun-exposed areas) erythematous rash
alopecia
oral ulcers
what are the systemic findings in lupus erythematosis?
synovitis
serositis (pleurisy/pericarditis)
renal disorder
neurological disorder
what are the haematological findings in lupus erythematosis?
haemolytic anaemia
thrombocytopenia
leukopenia
what are the immunological findings in lupus erythematosis?
ANA
anti-dsDNA
anti-Sm
antiphospholipid
low complement
positive direct Coomb’s test
what are the cutaneous manifestations of systemic lupus erythematosus?
photo-distributed rash
chillblains
alopecia
cutaneous vasculitis (w palpable purpura) = purple spots/rashes bc of internal bleeding
livedo reticularis
what are the signs of discoid lupus erythematosus?
limited to cutaneous effect only, will not affect other organ systems SO
- scarring (most prominent feature)
what do annular ring-like plaques suggest in a patient with lupus?
sign of subacute cutaneous lupus erythematosus
what is livedo reticularis?
net-like pattern of reddish-blue discolouration that
= indicates SLE
what is palpable purpura?
rash of purple spots on the skin due to internal bleeding from small blood vessels
= sign of SLE
a newborn presents with a ring-like annular rash
what is the most likely underlying disorder?
annular ring-like plaques in newborns indicate neonatal lupus
a newborn presents with a ring-like annular rash
what test must you do and why?
must do an ECG
= >50% risk that newborn has heart block and so urgently requires a pacemaker
what is dermatomyositis?
autoimmune connective tissue disease that causes muscle inflammation and skin rash
what are the two main features of dermatomyositis?
1) inflammatory myopathy
2) photo-distributed pink-violet rash
the muscles of which region are affected most commonly in dermatomyositis?
proximal extensors
= affected most by inflammatory myopathy
the skin of which region are affected most commonly in dermatomyositis?
scalp, periocular region, extensor surfaces
= affected most by photo-distributed skin rash
what are the key skin signs that are pathognomonic dermatomyositis?
Gottron’s papules
Shawl’s sign
ragged cuticles
heliotrope rash
photosensitive erythema
what are Gottron’s papules?
violaceous plaques on the MCP and distal ICP joints
what is Shawl’s sign?
redness of the upper back/trunk
what is a heliotrope rash?
violet, bluish-purple rash that develops on the skin
how are the subtypes of dermatomyositis differentiated?
different autoantibodies
what do anti Jo-1 antibodies in dermatomyositis suggest?
fever, myositis, Gottron’s papules
what do anti SRP antibodies in dermatomyositis suggest?
necrotising myopathy
what do anti p-155 antibodies in dermatomyositis suggest?
associated with malignancy in adults
which autoantibody would be associated with calcinosis in dermatomyositis?
anti p-140 antibody
why autoantibody is associated with amyopathic dermatomyositis?
anti SAE antibody
why autoantibody is associated with interstitial lung disease, digital ulcers and ischaemia in dermatomyositis?
anti MDA5 antibody
what do anti Mi-2 antibodies in dermatomyositis suggest?
mild muscle disease
which investigations are carried out for a patient with suspected dermatomyositis?
- ANA
- autoantibody panel for DMS
- LFT (as ALT is often increased)
- CK
- EMG (electromyography)
- skin biopsy
- screening for internal malignancy
what is IgA vasculitis?
(Henoch-Schonlein purpura)
when IgA antibodies collect in small blood vessels, which then become inflamed and leak blood
what are the symptoms of IgA vasculitis?
abdominal pain
gastrointestinal bleeding
arthralgia
arthritis
IgA-associated glomerulonephritis
why do the symptoms of IgA vasculitis occur?
vasculitis usually affect the small blood vessels of the GI tract
= abdominal pain, GI bleeding etc
which combination/types of blood vessels are commonly affected by vasculitis?
small
small & medium
medium
large
in which conditions are small vessels affected by vasculitis?
cutaneous small-vessel vasculitis
- (idiopathic, infectious, inflammatory, drug exposure)
- IgA vasculitis
- urticarial vasculitis
in which conditions are small & medium vessels affected by vasculitis?
ANCA-associated vasculitis
in which conditions are medium vessels affected by vasculitis?
polyarteritis nodosa (PAN)
in which conditions are large vessels affected by vasculitis?
temporal arteritis
tayakasu’s arteritis
what type of vasculitis do macular/palpable purpura indicate?
small vessel vasculitis
what are the main manifestations of medium vessel vasculitis?
digital necrosis
retiform purpura ulcers
subcutaneous nodules along blood vessels
differentiate between macular and palpable purpura
macular = flat palpable = raised
what is digital necrosis a sign of?
necrosis of the digits
= medium vessel vasculitis
what are retiform purpura ulcers a sign of?
medium vessel vasculitis
what are subcutaneous nodules along blood vessels a sign of?
medium vessel vasculitis
when can you get saddle-node deformity?
ANCA-associated vasculitis
= if granulomatous, needs to be treated aggressively as it can be fatal
what is sarcoidosis?
systemic granulomatous disorder of unknown origin with variable presentations
affects many organ systems, but mainly the lungs
can also have cutaneous manifestations
what are the cutaneous manifestations of sarcoidosis?
red-brown to violaceous papules and face, lips, upper back, neck, and extremities
lupus pernio
ulcerative
scar sarcoid
erythema nodosum
what is lupus pernio?
chronic raised indurated (hardened) lesion of the skin
what is erythema nodosum?
swollen fat under the skin causing red bumps and patches
what is the histology result for sarcoidosis?
non-caseating epithelioid granulomas
what must you do in a patient with sarcoidosis?
1) diagnosis of exclusion
2) requires evaluation of internal organ involvement
what is the most common skin sign of sarcoidosis?
granulomatous plaques
what is DRESS?
Drug Reaction with Eosinophilia and Systemic Symptoms
= severe hypersensitivity reaction to a drug that causes rash & systemic disturbance incorporating haematological and solid-organ disturbances
what is the diagnostic criteria for DRESS?
fever features:
- fever ≥ 38.5°C
- lymphadenopathy ⩾ 2 sites, > 1cm
blood features:
- circulating atypical lymphocytes
- peripheral hypereosinophilia > 0.7 × 109
- negative ANA & bacterial/viral cultures
involvement features:
- internal organs involvement (liver, kidneys, cardiac)
- skin involvement
what is the extent of skin involvement required for a diagnosis of DRESS?
1) > 50% BSA (body surface area)
2) cutaneous eruption suggestive of DRESS e.g. facial oedema
3) biopsy suggestive of DRES
which internal organs are involved in DRESS?
liver (mos frequent)
kidney (interstitial nephritis)
heart (myocarditis)
brain
thyroid (thyroiditis)
lung (interstitial pneumonitis)
which internal organ is the most frequent cause of death in DRESS?
liver
when do symptoms of DRESS first start to appear?
approx 2-6 week following drug exposure
which drugs are common triggers for DRESS?
sulfonamides antibiotics allopurinol anti-epileptics ibuprofen
what are the skin signs of DRESS?
neck/head oedema
erythema multiforme-like rash
erythroderma
maculopapular eruption
urticated papular exanthem
what is an erythema multiforme-like rash?
raised, red, target-like rash on the skin or mucous membranes
what is the treatment for DRESS?
withdraw culprit drug
administer corticosteroids
how can you tell if a rash is caused by an adverse drug reaction OR by graft versus host disease?
face involvement
acral involvement (limbs)
diarrhoea
= all indicate that GvHD is more likely than a rash
what is graft versus host disease?
a complication of an allogeneic stem cell transplantation wherein the donor T lymphocytes mount an immune response against the host cells
briefly explain the pathogenesis of GvHD
donor-derived T-lymphocytes (graft) mount an inappropriate immune response against antigens on host cells
which group of people are affected most by GvHD?
approx 10-80% of allogenic haematopoetic stem cell transplant patients
which parts of the body are affected most commonly by GvHD?
skin
liver
GI tracts
what is graft versus host disease?
a complication of an allogeneic stem cell transplantation wherein the donor T lymphocytes mount an immune response against the host cells
briefly explain the pathogenesis of GvHD
donor-derived T-lymphocytes (graft) mount an inappropriate immune response against antigens on host cells
which group of people are affected most by GvHD?
approx 10-80% of allogenic haematopoetic stem cell transplant patients
which parts of the body are affected most commonly by GvHD?
skin
liver
GI tract
define pruritus
itching
what does itching without a rash suggest?
suggestive of an internal cause
what are the possible causes of pruritus without a rash?
haemotological causes:
- polycythemia
- lymphoma
- iron deficiency/overload
diseases:
- HIV
- hepatitis A/B/C
- uraemia
- cholestasis
- cancer
pharmacological:
- drugs (opiates/opioids)
miscellaneous:
- pruritus of old age
- psychogenic
which investigations are carried out for pruritus?
FBC
liver function tests
renal profile
ferritin, LDH
test for HIV
test for hepatitis A/B/C
CXR
what can pruritus lead to?
nodular prurigo
what is nodular prurigo?
skin thickening in the form of large lumps due to excessive itching
what is scurvy?
vitamin C (ascorbic acid) deficiency
what are the systemic features of Kwashiorkor?
hepatomegaly bacterial/fungal infections oedema diarrhoea loss of muscle mass
what are the cutaneous manifestations of Kwashiorkor?
superficial desquamation
thin nails
sparse hair
chelitis (inflammation of the lips)
which nutritional deficiency are corkscrew hairs indicative of?
scurvy (vitamin C deficiency)
why is zinc important in the body?
required for the functioning of over 200 enzymes (lipid, nucleic acid synthesis)
would healing
antioxidant properties
which triad of symptoms is present in zinc deficiency?
Depression
Diarrhoea
Dermatitis
what are the cutaneous manifestations of zinc deficiency?
perineal, perioral and acral scaly erosive erythema
which tetrad of symptoms is present in niacin deficiency?
Diarrhoea
Dermatitis
Dementia
Death
what is niacin also known as?
vitamin B3
what are the cutaneous manifestations of niacin deficiency?
photodistributed erythema
Casal’s necklace
painful fissures of the palm and soles
perianal, perioral and genital inflammation and erosion
which nutritional deficiency is superficial desquamation indicative of?
kwashiorkor (protein deficiency)
which nutritional deficiency is Casal’s necklace indicative of?
vitamin B3 (niacin) deficiency
which nutritional deficiency is chelitis indicative of?
kwashiorkor (protein deficiency)
what is carcinoid syndrome?
occurs when a carcinoid tumour metastasises and secreted 5-HT into the systemic circulation
which molecule is secreted in large amounts in carcinoid syndrome?
5-HT
what are the symptoms of carcinoid syndrome?
flushing
diarrhoea
brochospasm
hypotension
what is SJS-TEN?
cell-mediated cytotoxic reaction against epidermal cells
what symptoms do SJS-TEN patients have in the early stages?
flu-like symptoms
how do the symptoms of an SJS-TEN patient develop?
flu-like symptoms
abrupt onset of lesions on trunk, face, limbs
macules, blisters, erythema
blisters merge
sheets of skin detachment
what is the characteristic cutaneous manifestation of SJS-TEN?
epidermal necrolysis = sheets of skin detachment
how long does it take for SJS-TEN patients to develop extensive full-thickness epidermal necrosis?
approx 2-3 days
why does SJS-TEN refer to two conditions?
one a continuum based on % BSA affected i.e. <10% affected = SJS 10-30% affected = SJS-TEN >30% affected = TEN
what constitutes the classification of SJS?
<10% BSA = SJS
what constitutes the classification of TEN?
10-30% BSA = SJS-TEN
what constitutes the classification of SJS-TEN?
> 30% BSA = TEN
what is the mortality of SJS compared to TEN?
10%-
which two prognostic scores are used for SJS-TEN?
30%+
what causes SJS-TEN?
drugs cause >80% of cases
which drugs can cause SJS-TEN?
sulphonamides antibiotics allopurinol anti-epileptics NSAIDs (e.g. ibuprofen)
(same list as drugs that cause DRESS!)
which conditions resemble SJS-TEN?
SSSS (staphylococcal scalded skin syndrome)
graft versus host disease
thermal burns
what is the criteria for SCORTEN?
a prognostic tool used to assess severity of SJS-TEN
- age > 40
- HR
- initial % epidermal detachment
- presence of malignancy
- serum urea, glucose, bicarb
what are the complications for SJS-TEN?
mortality rate = >30% = death
blindness dehydration hypothermia/hyperthermia renal tubular necrosis eroded GI tract interstitial pneumonitis, neutropenia liver and heart failure psychological (e.g. PTSD)
what is erythroderma?
generalized erythema affecting >90% of BSA
what are the systemic manifestations of erythroderma?
peripheral oedema
tachycardia
loss of fluid and proteins
disturbances in thermoregulation
risk of sepsis
what causes erythroderma?
drug reactions
psoriasis
atopic eczema
idiopathic
cutaneous T-cell lymphoma = Sezary syndrome
(padic mnemonic)
how is erythroderma treated?
treat underlying cause OR hospitalise
treat w emollients to support skin barrier
topical steroids, antibiotics
restore fluid and electrolyte balance, circulatory status and manage body temperature
what are the cutaneous signs of chronic kidney disease?
excoriations prurigo xerosis half & half nails calciphylaxis
(anaemia = mucosal pallor, hair thinning)
1) signs related to causal primary disease (ANCA vasculitis, SLE)
2) signs related to immunosuppression (viral warts)
what are the cutaneous signs of chronic liver disease?
Terry's nails Muerhke's lines jaundice spider telangiectasia palmar erythema clubbing porphyria cutanea tardia
what is necrobiosis lipodica?
plaques with red-brown raised edge with yellow-brown atrophic centres
= indicative of diabetes mellitus
what is the treatment for necrobiosis lipodica?
topical/intralesional steroids
what are the cutaneous manifestations of diabetes mellitus?
Terry's nails xerosis granuloma annulare neuropathic ulcers acanthosis nigricans xanthelasma & xanthomata skin infections
which endocrinological disorder is indicated by pre-tibial myxoedema?
Graves’ disease
which endocrinological disorder is indicated by hyperpigmentation?
Addison’s disease
which endocrinological disorders are indicated by acne?
PCOS
acromegaly
Cushing’s
which endocrinological disorder is indicated by cutis gyrata verticis?
acromegaly
what are the cutaneous manifestations of acromegaly?
cutis gyrata verticis
acne
what are the cutaneous manifestations of HIV?
severe seborrhoeic dermatitis eosinophilic folliculitis extensive viral warts CMV ulceration severe psoriasis bacillary angiomatosis Norwegian scabies Kaposi sarcoma
what are the variable non-specific manifestations of HIV seroconversion?
urticaria
erythema multiforme
morbiliform rash
oral/geniral ulceration
= so, low threshold for testing
what kind of infections are patients with HIV likely to contract?
opportunistic infections
atypical manifestations of common infections
severe forms of common dermatoses (severe seborrhoeic dermatitis, severe psoriasis)
suggestive dermatoses (eosinophilic folliculitis)
what are the cutaneous manifestations of IBD?
pyoderma gangrenosum
orofacial granulomatosis
panniculitis (erythema nodosum)
aphthous ulceration
associated with psoriasis, pemphigoid
what GI condition is dermatitis herpetiformis associated with?
coeliac disease
what can hidradenitis suppurtiva suggest?
high BMI, diabetes mellitus OR inflammatory bowel disease
describe the pathology of hidradenitis suppuritiva
inflamed nodes + abscesses rupture and cause extensive scarring
= pain, malodour, discharge
which regions of the body are most commonly affected by hidradenitis suppuritiva?
intertriginous zones (zones w two skin areas rubbing against each other)
- axillary, anogenital, inframammary
what is pyoderma gangrenosum?
painful pustule on an erythematous base that ulcerates and has a necrotic border
which conditions are associated with pyoderma gangrenosusm?
inflammatory bowel disease
seronegative arthritis
leukaemia
which skin diseases are associated with malignancy?
dermamyositis
erythema gyratum repens
pyoderma gangrenosum
paraneoplastic pepmhigus
(depp)
which genetic conditions predispose to internal cancer and
Peutz-Jeghers syndrome
hereditary leiomyomatosis
renal cell cancer
which condition is indicated as a result of peau d’orange?
breast carcinoma
which condition is indicated as a result of groin metastases?
prostatic carcinoma
which condition is indicated as a result of leukaemia cutis?
leukaemia
which condition is indicated as a result of haemorrhagic nodules?
metastatic pancreatic carcinoma
which condition is indicated as a result of extramammary Paget’s disease?
renal/pelvic malignancy
which condition is indicated as a result of acanthosis nigricans?
diabetes
which condition is indicated as a result of Paget’s disease of the nipple?
breast carcinoma
which condition is indicated as a result of erythema gyratum repens?
bronchial carcinoma
which condition is indicated as a result of paraneoplastic pemphigus?
malignancy
which condition is indicated as a result of mucosal melanosis?
Peutz-Jeghers syndrome (genetic)
which condition is indicated as a result of leiomyomas?
hereditary leiomyomatosis with renal cell cancer