The Skin In Systemic Disease Flashcards
In what four ways can the skin be involved in systemic disease?
Skin targeted
- Multi-organ systemic disease targeting skin, e.g. sarcoidosis
Skin signs
- Sign of internal disorder, e.g. flushing in Carcinoid syndrome
‘Tell-tale’ skin conditions
- Skin conditions suggestive of an underlying condition, e.g. Pyoderma gangrenosum in IBD
Secondary systemic involvement
- Systemic disease is secondary to skin disorder, e.g. high cardiac output failure in erythroderma
What blood tests are run for investigation in dermatology?
FBC
Renal profile
LFT
Inflammatory markers
Autoimmune serology
What microbiology tests are performed in dermatology?
Viral/bacterial serology
Swabs for bacteria C&S
Viral PCR tissue culture
PCR
What does imaging investigate I’m dermatology?
Internal organ involvement
Vascular supply
Aside from blood tests, microbiology and imaging, what other clinical tests are performed in dermatology?
Skin biopsy - microscopy
Specific tests - urinalysis, nerve conduction studies, endocrine investigations
What technique is observed in the image below?
Punch biopsy - sample of skin is taken under local anaesthetic
Sample can be sent for histology, tissue culture and antibody analysis
What are the two main groups of lupus erythematosus and are they distinct?
Systemic Lupus Erythematosus
Cutaneous (discoid) Lupus Erythematosus
There is an overlap between the groups
What categories do the diagnostic criteria of SLE fit under?
Mucocutaneous
Involvement of the joints and organs
Haematological - specifically reduced RBC count
Immunological - presence of antibodies
What does this image show?
Photodistributed (sun-exposed areas) erythematous rash
Symptom of SLE
What does this image show?
Chilblains (itchy swellings)
Found in SLE
What are the features of SLE?
Photodistributed rash
Cutaneous vasculitis (inflammation of blood vessels)
Chilblains
Alopecia (hair loss)
Livedo reticularis (net-like redness)
Subacute cutaneous lupus (SCLE) - ring/annular pattern
What does this image show?
Livedo reticularis
What does this image show?
Subacute cutaneous lupus
What does this image show?
Palpable purpura
What are the features of Cutaneous Lupus Erythematosus?
Discoid lupus erythematosus
SCLE (overlap)
What is the difference between discoid lupus and subacute lupus?
Discoid lupus characteristically causes scarring and SCLE doesn’t
Does SCLE always present with SLE?
No, can be systemic (SLE) or skin-limited (cutaneous lupus)
What is the underlying disorder in this picture and what test should be performed?
Neonatal lupus (Ro positive)
ECG should be performed - up to 50% risk of heart block
What is dermatomyositis and what are its key features?
Autoimmune connective tissue disease
Proximal extensor inflammatory myopathy
Photo-distributed pink-violet rash favouring scalp, periocular region and extensor surfaces
Label these signs. What condition are they characteristic of?
Dermatomyositis
What can the different subtypes of dermatomyositis be predicted by?
Subtypes with clinical features can be predicted by autoantibody profile
E.g. Anti-MDA5 - interstitial lung disease, digital ulcers/ischaemia
What other tests can be used to support a diagnosis of dermatomyositis?
ANA
CK
Skin biopsy
LFT (ALT often increased)
Electromyography (EMG)
Screening for malignancy - important for management of condition
What symptoms does IgA vasculitis typically present with?
Abdominal pain
Bleeding
Arthralgia (joint pain)
Arthritis
GI-A associated glomerulonephritis (may develop later)
What does this image show and what is it a manifestation of?
Purpura (macular/palpable)
Manifestation of small vessel vasculitis
