Skin In Systemic Disease Flashcards
What investigations for neoplastic
- Imaging to look for internal organ involvement and vascular supply
- Skin biopsy and microscopy
IVX for infections
- Viral/bacterial serology
- Swabs for bacteria C&S, viral PCR
- Tissue culture/PCR
IVX autoimmune
- FBC
- Renal profile
- Liver function test
- Inflammatory markers
- Autoimmune serology
What is a punch biopsy?
- Biopsy of skin done under local anaesthetic
- Cells taken and examined for inflammatory patterns/cell abnormalities to look for neoplasia
- Can also look for autoantibodies through immunofluorescence
- Can also be sent for tissue culture
What are the 2 main categories of lupus erythematous
- Systemic lupus erythematosus
- Cutaneous (discoid) lupus erythematosus
What are the 3 types of diagnostic criteria for systemic lupus erythematosus
Mucocutaneous (4)
- Cutaneous lupus- acute- e.g. chillblains and photodistributed (Sun-exposed areas) erythematosus rash
- Cutaneous lupus- chronic
- Oral ulcers
- Alopecia
Hametaological
- Haemolytic anaemia
- Thrombocytopenia
- Leukopenia
Immunological
- ANA
- Anti-dsDNA
- Anti-Smith
- Antiphospholipid
- Low Complement
- Direct Coomb’s test
What other diagnostic criteria are there for sle
- Synovitis
- Serositis (pleurisy or pericarditis)
- Renal disorder
- Neurological disorder
Livedo reticularis (net like erythema)
Palpable purpura (Sam,, vessel cutaneous vasculitis)
Subacute cutaneous lupus (SCLE) (ring like annular plaques)
- What are the diagnostic criteria for cutaneous (discoid) lupus erythematosus? (2)
Discoid lupus erythematosus
SCLE
Neonatal lupus
Do ecg as 50% risk of heart block
What is dermatomyosistis
Autoimmune connective tissue disease
Characterized by - Proximal extensor inflammatory myopathy
- Photodistributed pink-violet rash favouring scalp, periocular regional and extensor surfaces
Distinct features of dermatomyositis (5)
Gottron’s papules
MCP and DIP joints
They are violacious plaques
Ragged cuticles
Shawl sign
Redness of upper trunk
Heliotrope rash
Erythema of eyelids
Photosensitive erythema
Multiple non cutaneous manifestations are linked to autoantibody status eg ILD,malignancies,arthritis
What different subtypes are there and what clinical features are they associated with for dermatomyositis (7)
- Anti Jo-1 (3)
- Fever
- Myositis
- Gottron’s papules
- Anti SRPNecrotising myopathy
- Anti Mi-2Mild muscle disease
- Anti p155Associated with malignancy in adults
- Anti p140Juvenile, associated with calcinosis
- Anti SAEWith or without amyopathy (no problems in muscle weakness)
- Anti MDA5 (2)
- Interstitial lung disease
- Digital ulcers/ischaemia
Diagnostic tests for dermatomyositis
Anti nuclear antibody as its positive in most cases
Liver function test as ALT is usually increased
CK
Dermatomyositis panel antibodies to figure out subtype
EMG
MRI muscles
Skin biopsy
Screening for internal malignancy via imaging and tumour markers as patients are at increased risk especially with p155
Macular purpara
Flat and not raised
Biopsy for direct immunofluorescence showing perivascular autoantibodies IgA- what is this?
IgA vasculitis (Henoch-Schonlein purpura)
- Abdominal pain
- GI bleeding
- Arthralgia (joint stiffness)
- Arthritis
- IgA-associated glomerulonephritis (may develop later)
What types of vasculitis are different sizes of blood vessels affected by?
Small
Small and medium
Medium
Large
Small vessel vasculitis
- Small vessel vasculitis- special types- subclassifications? (4)
- IgA vasculitis (Henoch-Scholein)
- Urticarial vasculitis
- Acute haemorrhagic oedema of infancy
- Erythema elevatum diutinum
- Cutaneous small vessel (leukocytoclastic) vasculitis- what are the subclassifications? (4)
- Idiopathic
- Inflammatory (connective tissue disease)
- Infectious
- Medication exposure
Small and medium vasculitis
- Cryoglobulinemia- subclassification?Type 2 or 3
- ANCA-associated- subclassification? (3)
- GPA (Wegener)
- EGPA (Churg-Strauss)
- Microscopic polyangiitis
Medium vasculitis
- Polyarteritis nodosa (PAN)- subclassifications? (2)
- Benign cutaneous form
- Systemic form
Large vasculitis
- Temporal arteritis
- Tayakasu
What are small vessel manifestations of vasculitis
Purpura both macular and palpable
What are medium vessel manifestations of the disease
Digital necrosis
Retiform ‘net like’ purpura ulcer
Subcutaneous nodules
What is drug reaction with eosinophilia and systemic symptoms
Rash and systemic upset involving haematological and solid-organ disturbances
What are the scoring criteria for DRESS? (patients don’t have to have all of them, just score up to a certain amount of them) (7)
- Fever ≥38.5°C
- Lymphadenopathy ≥2 sites, 1cm
- Circulating atypical lymphocytes
- Peripheral hypereosinophilia >0.7 x 10^9
- Internal organs involved- what does this include? (6)
- Liver (hepatitis)- most frequent cause of death
- Kidneys (interstitial nephritis)
- Heart (myocarditis)
- Thyroid (thyroiditis)
- Lungs (interstitial pneumonitis)
- Brain
- Negative ANA, hepatitis/mycoplasma, chlamydia
- Skin involvement
- > 50% BSA (body surface area)
- Cutaneous eruption suggestive of DRESS e.g. facial oedema
- Biopsy suggestive of DRESS
Mechanism of DRESS and common drug triggers
- Underlying mechanism not known
- Starts 2-6 weeks after drug exposure
- Sulfonamides
- Allopurinol
- Anti-epileptics (lamotrigine, carbamazepine, phenytoin)
- antibiotics (vancomycin, amoxicillin, minocycline, piperacillin-tazobactam)
- Ibuprofen
DRESS rash looks like
- Urticated papular exanthem- widespread papules e.g. bottom right pic
- Maculopapular (morbilliform) eruption
- Widespread erythema (erythroderma)
- Head/neck oedema
- Erythema multiforme-like (with targetoid lesions) e.g. top right pic
Treatment of DRESS
- Withdrawal of culprit
- Corticosteroids are first line treatment- may require months of treatment
- 5-10% mortality
What does itching without a rash suggest
Internal causes
Consider:
- Haematological causes (lymphoma, polycythaemia)
- Uraemia
- Cholestasis
- Iron deficiency or iron overload
- HIV/hepatitis ABC
- Cancer
- Drugs (esp opiates/opioids)
- Psychogenic
- Pruritus of old age
What tests do ‘itching without a rash’ patients need? (6)
- FBC, LDH
- Renal profile
- Liver function test
- Ferritin
- CXR
- HIV/hep ABC test
What do patients develop if they keep itching?
Nodular prurigo- skin thickening as a defence mechanism from the scratch
What is the sequence of development of symptoms? (5 steps) for steven Johnson syndrome/toxic epidermal necrolysis
1) Prodrome of flu-like symptoms
2) Abrupt onset of lesions on trunk then face/limbs
3) Macules, blisters, erythema- atypical targetoid
4) Blisters then merge and sheets of skin detach ‘like wet wallpaper’
5) This represents extensive full thickness mucocutaneous (epidermal) necrosis in 2-3 days
This is a derm emergency (rare)
When is the disease called SJS and when TEN?
- When <10% of BSA detachment → SJS
- When 10-30% of BSA detachment → SJS/TEN
- When >30% of BSA detachment → TEN
What is its pathophysiology sjs
Cell-mediated cytotoxic reaction against epidermal cells
Caused by drugs and may be started up to 3 weeks before rash onset
- Antibiotics e.g. beta-lactams, sulphonamides
- Allopurinol
- Anti-epileptic drugs e.g. phenytoin, carbamazepine, lamotrigine
- NSAIDs
Differential diagnosis for SJS
- Staphylococcal scalded skin syndrome (SSSS)
- Thermal burns
- Cutaneous GvHD
Severity if sjs determined by
SCORTEN score calculated with criteria:
- Age >40
- Initial % epidermal detachment
- Serum urea + glucose + bicarbonate
- Presence of malignancy
What complications are there? (9) sjs
- Death- overall mortality is 30%
- Blindness
- Dehydration
- Hypothermia/hyperthermia
- Renal tubular necrosis
- Eroded GI tract
- Interstitial pneumonitis
- Neutropenia
- Liver and heart failure
Erythoderma
Generalised erythema affecting >90% BSA
What can it manifest as systemically? (5) erythoderma
- Peripheral oedema
- Tachycardia
- Loss of fluid and proteins
- Disturbances in thermoregulation
- Risk of sepsis
What can cause erythoderma (5)
- Drug reactions
- Cutaneous T-cell lymphoma called Sezary syndrome
- Sudden flare up of psoriasis
- Atopic eczema
- Idiopathic (25-30%)
Management of erythoderma (6)
- Underlying cause (e.g. treat psoriasis, withdraw drug if drug cause etc)
- Hospitalisation if systemically unwell
- Restore fluid and electrolyte balance, circulatory status and manage body temp
- Emollients to support skin barrier
- Maybe topical steroids
- Maybe antibiotics
Nutritional disdoers
Scurvy which is caused by vitamin c deficiency can cause spongy gingivae bleeding erosion petechiea echymoses corkscrew hair
Kwashiorkor caused by protein deficiency can cause sparse dry hair soft thin nails and cheilitis
Malignancy
Leukaemia cutis
Paget’s disease if nipple
Extramammory pagets
Acanthosis nigricans
Leiomyomas
Chronic kidney disease
Excoriations/prurigo
Xerosis
Half and half nails
Calciohylaxis
Chronic live disease
Prurigo
Jaundice
Muehrckes line
Terrys nails
Palmar erythema
Spider telangeictasia
Clubbing if nails
Endocrine disorder
Necrobiosis Lipoidica
Terry’s nails
Xerosis
Granuloma annulare
Xanthelesma
Xanthoma
Neuropathic ulcers
Cutaneous signs of erythoderma
Excoriations /pruririgo
Xerosis
Half and half nails
Calciphylaxis
