(derm) the skin in systemic disease Flashcards
1
Q
why is the skin important in systemic disease?
A
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
2
Q
what are three ways in which the skin can indicate systemic disease?
A
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)
3
Q
which systemic disease does pyoderma gangrenosum suggest?
A
inflammatory bowel disease
4
Q
which blood tests are commonly done in dermatology?
A
full blood count
renal profile
liver function tests
inflammatory markers
autoimmune serology
5
Q
which microbiology tests are commonly done in dermatology?
A
viral/bacterial serology
swabs for bacteria culture & sensitivities, viral PCR
tissue culture/PCR
6
Q
which specialist tests are commonly done in dermatology?
A
skin biopsy
imaging
microscopy
7
Q
what is a punch biopsy?
A
taking a punch-size piece of skin from the body
8
Q
when are punch biopsies taken?
A
to study suspected melanomas, invasive carcinomas, inflammatory lesions and neoplasias
9
Q
how are punch biopsies studied?
A
identify inflammatory patterns and cellular abnormalities
to detect autoantibodies in immunofluorescence
skin biopsy, tissue culture
10
Q
what are the two main types of lupus erythematosus?
A
systemic lupus erythematosus = SLE
chronic cutaneous (discoid) lupus erythematosus = DLE
11
Q
define pancytopenia
A
deficiency of all three cellular components of the blood (red cells, white cells, and platelets)
12
Q
what are the musculocutaneous findings in lupus erythematosus?
A
chillblains
photo-distributed (sun-exposed areas) erythematous rash
alopecia
oral ulcers
13
Q
what are the systemic findings in lupus erythematosis?
A
synovitis
serositis (pleurisy/pericarditis)
renal disorder
neurological disorder
14
Q
what are the haematological findings in lupus erythematosis?
A
haemolytic anaemia
thrombocytopenia
leukopenia
15
Q
what are the immunological findings in lupus erythematosis?
A
ANA
anti-dsDNA
anti-Sm
antiphospholipid
low complement
positive direct Coomb’s test
16
Q
what are the cutaneous manifestations of systemic lupus erythematosus?
A
photo-distributed rash
chillblains
alopecia
cutaneous vasculitis (w palpable purpura) = purple spots/rashes bc of internal bleeding
livedo reticularis
17
Q
what are the signs of discoid lupus erythematosus?
A
limited to cutaneous effect only, will not affect other organ systems SO
- scarring (most prominent feature)
18
Q
what do annular ring-like plaques suggest in a patient with lupus?
A
sign of subacute cutaneous lupus erythematosus
19
Q
what is livedo reticularis?
A
net-like pattern of reddish-blue discolouration that
= indicates SLE
20
Q
what is palpable purpura?
A
rash of purple spots on the skin due to internal bleeding from small blood vessels
= sign of SLE
21
Q
a newborn presents with a ring-like annular rash
what is the most likely underlying disorder?
A
annular ring-like plaques in newborns indicate neonatal lupus
22
Q
a newborn presents with a ring-like annular rash
what test must you do and why?
A
must do an ECG
= >50% risk that newborn has heart block and so urgently requires a pacemaker
23
Q
what is dermatomyositis?
A
autoimmune connective tissue disease that causes muscle inflammation and skin rash
24
Q
what are the two main features of dermatomyositis?
A
1) inflammatory myopathy
2) photo-distributed pink-violet rash
25
the muscles of which region are affected most commonly in dermatomyositis?
proximal extensors
= affected most by inflammatory myopathy
26
the skin of which region are affected most commonly in dermatomyositis?
scalp, periocular region, extensor surfaces
= affected most by photo-distributed skin rash
27
what are the key skin signs that are pathognomonic dermatomyositis?
Gottron's papules
Shawl's sign
ragged cuticles
heliotrope rash
photosensitive erythema
28
what are Gottron's papules?
violaceous plaques on the MCP and distal ICP joints
29
what is Shawl's sign?
redness of the upper back/trunk
30
what is a heliotrope rash?
violet, bluish-purple rash that develops on the skin
31
how are the subtypes of dermatomyositis differentiated?
different autoantibodies
32
what do anti Jo-1 antibodies in dermatomyositis suggest?
fever, myositis, Gottron's papules
33
what do anti SRP antibodies in dermatomyositis suggest?
necrotising myopathy
34
what do anti p-155 antibodies in dermatomyositis suggest?
associated with malignancy in adults
35
which autoantibody would be associated with calcinosis in dermatomyositis?
anti p-140 antibody
36
why autoantibody is associated with amyopathic dermatomyositis?
anti SAE antibody
37
why autoantibody is associated with interstitial lung disease, digital ulcers and ischaemia in dermatomyositis?
anti MDA5 antibody
38
what do anti Mi-2 antibodies in dermatomyositis suggest?
mild muscle disease
39
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
40
what is IgA vasculitis?
(Henoch-Schonlein purpura)
| when IgA antibodies collect in small blood vessels, which then become inflamed and leak blood
41
what are the symptoms of IgA vasculitis?
abdominal pain
gastrointestinal bleeding
arthralgia
arthritis
IgA-associated glomerulonephritis
42
why do the symptoms of IgA vasculitis occur?
vasculitis usually affect the small blood vessels of the GI tract
= abdominal pain, GI bleeding etc
43
which combination/types of blood vessels are commonly affected by vasculitis?
small
small & medium
medium
large
44
in which conditions are small vessels affected by vasculitis?
cutaneous small-vessel vasculitis
- (idiopathic, infectious, inflammatory, drug exposure)
- IgA vasculitis
- urticarial vasculitis
45
in which conditions are small & medium vessels affected by vasculitis?
ANCA-associated vasculitis
46
in which conditions are medium vessels affected by vasculitis?
polyarteritis nodosa (PAN)
47
in which conditions are large vessels affected by vasculitis?
temporal arteritis
| tayakasu's arteritis
48
what type of vasculitis do macular/palpable purpura indicate?
small vessel vasculitis
49
what are the main manifestations of medium vessel vasculitis?
digital necrosis
retiform purpura ulcers
subcutaneous nodules along blood vessels
50
differentiate between macular and palpable purpura
```
macular = flat
palpable = raised
```
51
what is digital necrosis a sign of?
necrosis of the digits
= medium vessel vasculitis
52
what are retiform purpura ulcers a sign of?
medium vessel vasculitis
53
what are subcutaneous nodules along blood vessels a sign of?
medium vessel vasculitis
54
when can you get saddle-node deformity?
ANCA-associated vasculitis
= if granulomatous, needs to be treated aggressively as it can be fatal
55
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
56
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
57
what is lupus pernio?
chronic raised indurated (hardened) lesion of the skin
58
what is erythema nodosum?
swollen fat under the skin causing red bumps and patches
59
what is the histology result for sarcoidosis?
non-caseating epithelioid granulomas
60
what must you do in a patient with sarcoidosis?
1) diagnosis of exclusion
| 2) requires evaluation of internal organ involvement
61
what is the most common skin sign of sarcoidosis?
granulomatous plaques
62
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
63
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
64
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
65
which internal organs are involved in DRESS?
liver (mos frequent)
kidney (interstitial nephritis)
heart (myocarditis)
brain
thyroid (thyroiditis)
lung (interstitial pneumonitis)
66
which internal organ is the most frequent cause of death in DRESS?
liver
67
when do symptoms of DRESS first start to appear?
approx 2-6 week following drug exposure
68
which drugs are common triggers for DRESS?
```
sulfonamides
antibiotics
allopurinol
anti-epileptics
ibuprofen
```
69
what are the skin signs of DRESS?
neck/head oedema
erythema multiforme-like rash
erythroderma
maculopapular eruption
urticated papular exanthem
70
what is an erythema multiforme-like rash?
raised, red, target-like rash on the skin or mucous membranes
71
what is the treatment for DRESS?
withdraw culprit drug
administer corticosteroids
72
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
73
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
74
briefly explain the pathogenesis of GvHD
donor-derived T-lymphocytes (graft) mount an inappropriate immune response against antigens on host cells
75
which group of people are affected most by GvHD?
approx 10-80% of allogenic haematopoetic stem cell transplant patients
76
which parts of the body are affected most commonly by GvHD?
skin
liver
GI tracts
77
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
78
briefly explain the pathogenesis of GvHD
donor-derived T-lymphocytes (graft) mount an inappropriate immune response against antigens on host cells
79
which group of people are affected most by GvHD?
approx 10-80% of allogenic haematopoetic stem cell transplant patients
80
which parts of the body are affected most commonly by GvHD?
skin
liver
GI tract
81
define pruritus
itching
82
what does itching without a rash suggest?
suggestive of an internal cause
83
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
84
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
85
what can pruritus lead to?
nodular prurigo
86
what is nodular prurigo?
skin thickening in the form of large lumps due to excessive itching
87
what is scurvy?
vitamin C (ascorbic acid) deficiency
88
what are the systemic features of Kwashiorkor?
```
hepatomegaly
bacterial/fungal infections
oedema
diarrhoea
loss of muscle mass
```
89
what are the cutaneous manifestations of Kwashiorkor?
superficial desquamation
thin nails
sparse hair
chelitis (inflammation of the lips)
90
which nutritional deficiency are corkscrew hairs indicative of?
scurvy (vitamin C deficiency)
91
why is zinc important in the body?
required for the functioning of over 200 enzymes (lipid, nucleic acid synthesis)
would healing
antioxidant properties
92
which triad of symptoms is present in zinc deficiency?
Depression
Diarrhoea
Dermatitis
93
what are the cutaneous manifestations of zinc deficiency?
perineal, perioral and acral scaly erosive erythema
94
which tetrad of symptoms is present in niacin deficiency?
Diarrhoea
Dermatitis
Dementia
Death
95
what is niacin also known as?
vitamin B3
96
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
97
which nutritional deficiency is superficial desquamation indicative of?
kwashiorkor (protein deficiency)
98
which nutritional deficiency is Casal's necklace indicative of?
vitamin B3 (niacin) deficiency
99
which nutritional deficiency is chelitis indicative of?
kwashiorkor (protein deficiency)
100
what is carcinoid syndrome?
occurs when a carcinoid tumour metastasises and secreted 5-HT into the systemic circulation
101
which molecule is secreted in large amounts in carcinoid syndrome?
5-HT
102
what are the symptoms of carcinoid syndrome?
flushing
diarrhoea
brochospasm
hypotension
103
what is SJS-TEN?
cell-mediated cytotoxic reaction against epidermal cells
104
what symptoms do SJS-TEN patients have in the early stages?
flu-like symptoms
105
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
106
what is the characteristic cutaneous manifestation of SJS-TEN?
epidermal necrolysis = sheets of skin detachment
107
how long does it take for SJS-TEN patients to develop extensive full-thickness epidermal necrosis?
approx 2-3 days
108
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
```
109
what constitutes the classification of SJS?
<10% BSA = SJS
110
what constitutes the classification of TEN?
10-30% BSA = SJS-TEN
111
what constitutes the classification of SJS-TEN?
>30% BSA = TEN
112
what is the mortality of SJS compared to TEN?
10%-
113
which two prognostic scores are used for SJS-TEN?
30%+
114
what causes SJS-TEN?
drugs cause >80% of cases
115
which drugs can cause SJS-TEN?
```
sulphonamides
antibiotics
allopurinol
anti-epileptics
NSAIDs (e.g. ibuprofen)
```
(same list as drugs that cause DRESS!)
116
which conditions resemble SJS-TEN?
SSSS (staphylococcal scalded skin syndrome)
graft versus host disease
thermal burns
117
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
118
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)
```
119
what is erythroderma?
generalized erythema affecting >90% of BSA
120
what are the systemic manifestations of erythroderma?
peripheral oedema
tachycardia
loss of fluid and proteins
disturbances in thermoregulation
risk of sepsis
121
what causes erythroderma?
drug reactions
psoriasis
atopic eczema
idiopathic
cutaneous T-cell lymphoma = Sezary syndrome
(padic mnemonic)
122
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
123
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)
124
what are the cutaneous signs of chronic liver disease?
```
Terry's nails
Muerhke's lines
jaundice
spider telangiectasia
palmar erythema
clubbing
porphyria cutanea tardia
```
125
what is necrobiosis lipodica?
plaques with red-brown raised edge with yellow-brown atrophic centres
= indicative of diabetes mellitus
126
what is the treatment for necrobiosis lipodica?
topical/intralesional steroids
127
what are the cutaneous manifestations of diabetes mellitus?
```
Terry's nails
xerosis
granuloma annulare
neuropathic ulcers
acanthosis nigricans
xanthelasma & xanthomata
skin infections
```
128
which endocrinological disorder is indicated by pre-tibial myxoedema?
Graves' disease
129
which endocrinological disorder is indicated by hyperpigmentation?
Addison's disease
130
which endocrinological disorders are indicated by acne?
PCOS
acromegaly
Cushing's
131
which endocrinological disorder is indicated by cutis gyrata verticis?
acromegaly
132
what are the cutaneous manifestations of acromegaly?
cutis gyrata verticis
| acne
133
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
```
134
what are the variable non-specific manifestations of HIV seroconversion?
urticaria
erythema multiforme
morbiliform rash
oral/geniral ulceration
= so, low threshold for testing
135
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)
136
what are the cutaneous manifestations of IBD?
pyoderma gangrenosum
orofacial granulomatosis
panniculitis (erythema nodosum)
aphthous ulceration
associated with psoriasis, pemphigoid
137
what GI condition is dermatitis herpetiformis associated with?
coeliac disease
138
what can hidradenitis suppurtiva suggest?
high BMI, diabetes mellitus OR inflammatory bowel disease
139
describe the pathology of hidradenitis suppuritiva
inflamed nodes + abscesses rupture and cause extensive scarring
= pain, malodour, discharge
140
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
141
what is pyoderma gangrenosum?
painful pustule on an erythematous base that ulcerates and has a necrotic border
142
which conditions are associated with pyoderma gangrenosusm?
inflammatory bowel disease
seronegative arthritis
leukaemia
143
which skin diseases are associated with malignancy?
dermamyositis
erythema gyratum repens
pyoderma gangrenosum
paraneoplastic pepmhigus
(depp)
144
which genetic conditions predispose to internal cancer and
Peutz-Jeghers syndrome
hereditary leiomyomatosis
renal cell cancer
145
which condition is indicated as a result of peau d'orange?
breast carcinoma
146
which condition is indicated as a result of groin metastases?
prostatic carcinoma
147
which condition is indicated as a result of leukaemia cutis?
leukaemia
148
which condition is indicated as a result of haemorrhagic nodules?
metastatic pancreatic carcinoma
149
which condition is indicated as a result of extramammary Paget's disease?
renal/pelvic malignancy
150
which condition is indicated as a result of acanthosis nigricans?
diabetes
151
which condition is indicated as a result of Paget's disease of the nipple?
breast carcinoma
152
which condition is indicated as a result of erythema gyratum repens?
bronchial carcinoma
153
which condition is indicated as a result of paraneoplastic pemphigus?
malignancy
154
which condition is indicated as a result of mucosal melanosis?
Peutz-Jeghers syndrome (genetic)
155
which condition is indicated as a result of leiomyomas?
hereditary leiomyomatosis with renal cell cancer
