the skin in systemic disease Flashcards
why is it important to look at the skin?
Rashes may be more than skin deep
Comprehensive assessment coupled with dermatological diagnostic skills can:
- Prevent or reduce internal organ damage by early diagnosis
- Allow detection of internal malignancy
in what ways can the skin play a role in systemic disease?
skin targeted -in diseases such as sarcoidosis
skin signs - may be present in internal disorders, such as flushing in carcinoid syndrome
tell-tale skin conditions - Skin conditions suggestive of underlying condition e.g. Pyoderma gangrenosum in inflammatory bowel disease
secondary skin involvement - Systemic disease secondary to skin disorder e.g. high output cardiac failure in erythroderma
what is a punch biopsy?
skin investigation taken under local anaesthetic
can be sent for histology - cells and inflammatory patterns and cellular abnormalities
checks for neoplasia or invasive cancer
can also be sent for immuno flourescencing, in which auto antibodies can be detected
they can also be sent for tissue culture
what is lupus erythematosus?
Two main groups:
Systemic Lupus Erythematosus
Cutaneous (Discoid) Lupus Erythematosus
- Overlap
what is the diagnostic criteria for systemic lupus erythematosus?
Cutaneous lupus - acute
Cutaneous lupus - chronic {Mucocutaneous}
Oral ulcers
Alopecia
Synovitis (joints)
Serositis (pleurisy or pericarditis)
Renal disorder
Neurological disorder
Haemolytic anaemia
Thrombocytopenia {Haematological}
Leukopenia
ANA
Anti-dsDNA
Anti-Sm
Antiphospholipid {Immunological}
Low Complement
Direct Coomb’s test
what are some symptoms (visible) of SLE?
Photodistributed rash (on areas exposed to the sun)
Cutaneous vasculitis
Chilblains
Alopecia
Livedo reticularis (nettle like erythema)
palpable purpura
Cutaneous vasculitis
Subacute cutaneous lupus (SCLE) (ring like/annular plaque) (also seen in cutaneous lupus erythemqtosus)
what are some symptoms of cutaneous lupus erythematosus?
in 95% of cases, no other organ involves - cutaneous only
distinct scarring (eg. on scalp and cheek)
also subacute cutaneous lupus (SCLE)
what is neonatal lupus?
one exception where you can make a spot diagnosis (dont need differential)
neonatal lupus (Ro positive)
Test ECG
– comes with arisk of heart block (50% risk)
shows up with annular/ring like plaques - subacute cutaneous lupus (SCLE)
what is dermatomyositis?
Autoimmune connective tissue disease
Proximal extensor inflammatory myopathy (muscle weakness)
Photo-distributed pink-violet rash favouring scalp, periocular regional and extensor surfaces
what are some distinct signs of dermatomyositis?
Photosensitive erythema - Photo-distributed pink-violet rash favouring scalp, periocular regional and extensor surfaces
Gottron’s papules - metacarpophylangeal joints and distal interphylangeal joints, vereacious plaques
Ragged cuticles - of nails
Shawl sign - redness on upper back/trunk
Heliotrope rash - erythema of the eyelids
muscle weakness
what are the subtypes of dermatomyositis?
Subtypes with clinical features that can be predicted by autoantibody profile
Anti Jo-1 – fever, myositis, gottron’s papules
Anti SRP – nectrotising myopathy
Anti Mi-2 – mild muscle disease
Anti-p155 – associated with malignancy (in adults)
Anti-p140 – juvenile, associated with calcinosis
Anti-SAE- +/- amyopathic
Anti- MDA5 – interstitial lung disease, digital ulcers / ischaemia
what investigations are done for dermatomyositis?
ANA (antinuclear antibodies) CK (creatine kinase) (muscles) Skin biopsy LFT (ALT often increased) EMG (electromyography) Screening for internal malignancy
what is IgA vasculitis?
vasculitis effecting the small blood vessels
Abdominal pain, bleeding, arthralgia, arthritis, IgA- associated, macula purpura (flat)
glomerulonephritis- may develop later
how does small vessel vasculitis present?
Purpura (macular / palpable)
macular is flat, papular is raised
how does medium vessel vasculitis present?
Digital necrosis
Subcutaneous nodules along blood vessels
Retiform purpura Ulcers
what is ANCA associated vasculitis?
small and medium vessel
can get nose saddle deformities
cough, dyspnoea, chest pain
ulcerative rash
stuffy nose and nosebleeds
what is sarcoidosis?
Systemic granulomatous disorder of unknown origin
Can affect multiple organs: most commonly lungs
Cutaneous manifestations in ~33%
- Highly variable – ‘the great mimicker’
- Red-brown to violaceous papules and face, lips, upper back, neck, and extremities
Lupus pernio – NB (nothing to do with lupus, redness on face) (often on nose ears and lips, often shiny, blue-red)
Ulcerative
Scar sarcoid
Erythema nodosum (lower legs, fat inflammation)
Histology – non-caseating epithelioid granulomas (no necrosis)
Diagnosis of exclusion
Requires evaluation for internal organ involvement
what is DRESS?
Drug Reaction with Eosinophilia and Systemic Symptoms
Rash and systemic upset incorporating haematological and solid‐organ disturbances
Underlying mechanism not known
Starts 2-6 weeks after drug exposure
Liver most common internal organ involved – majority of deaths associated with this
Sulfonamides, anti-epileptics (carbamazepine, phenytoin, lamotrigine), allopurinol, Antibiotics (vancomycin, amoxicillin, minocycline, piperacillin-tazobactam), ibuprofen are common triggers
what are the diagnostic criteria for DRESS?
Diagnosis is based on scoring criteria including:
Fever ≥ 38.5°C
Lymphadenopathy ⩾ 2 sites, > 1cm
Circulating atypical lymphocytes
Peripheral hypereosinophilia >0.7 × 109
Internal organs involved - (liver, kidneys, cardiac
Negative ANA, Hepatitis / mycoplasma, chlamydia
Skin involvement:
>50% BSA
Cutaneous eruption suggestive of DRESS e.g. facial oedema
Biopsy suggestive of DRESS
what internal organ involvement is present in DRESS?
Liver (hepatitis)- most frequent cause of death Kidneys (interstitial nephritis) Heart (myocarditis) Brain Thyroid (thyroiditis) Lungs (interstitial pneumonitis)
