👍🏻Dermatology👍🏻- Skin in Systemic Disease Flashcards
Why is the skin in systemic disease important?
Rashes may be more than “skin deep”
Prevent or reduce internal organ damage by early diagnosis
Allow detection of internal malignancy
What are the two main groups of lupus erythematosus?
Systemic lupus erythematosus
Cutaneous (discoid) lupus erythematosus
What is categories can the diagnostic criteria for lupus be broken down into?
Mucocutaneous
Haematological
Immunological
What are the haematological signs of SLE?
Haemolytic anaemia
Thrombocytopenia
Leukopenia
What immunological investigations can be carried out for lupus?
ANA (high)
Anti-dsDNA (high)
Anti-Sm (high)
Antiphospholipid (high)
Complement level (low)
Direct Coomb’s test (detects antibodies attached to red blood cells)
What is ANA?
Anti-nuclear antibodies
Screening test for pretty much all autoimmune conditions, particularly dermatological ones
What are the signs and symptoms of SLE?
Photodistributed rash
Cutaneous vasculitis
Chilblains
Alopecia
Livedo reticularis
Cutaneous vasculitis
Subacute cutaneous lupus (SCLE)
What are the signs and symptoms of cutaneous (discoid) lupus erythematosus?
Discoid lupus erythematosus
SCLE
Overlap with SLE
What is livedo reticularis?
Impaired blood flow leads to small clots and vessel spasms
Lacy, net like pattern on the skin
What are chilblains?
Inflamed swollen patches and blistering on the hands and feet
What is alopecia?
Hair loss (can be patches of hair or full head of hair)
Can be temporary or permanent
What is cutaneous vasculitis?
Inflammation of the small blood vessels in the skin
What is subacute cutaneous lupus (SCLE)?
red, scaly, or raised lesions on the skin
What is discoid lupus?
Red, inflamed, scaly, and crusty patches of skin
Lesions that are often found on the scalp, cheeks, and ears
How might a patient present with SLE?
New onset (weeks) of:
Rash
Fever
Arthritis
Fatigue
Bloods show:
Pancytopenia
Proteinuria
Increased ESR / CRP
ANA 1:640
dsDNA positive
What is dermatomyositis?
Autoimmune connective tissue disease
Proximal extensor inflammatory myopathy
What are the characteristic features of dermatomyositis?
Photo-distributed pink-violet rash favouring scalp, periocular regional and extensor surfaces
How can the clinical features of dermatomyositis be predicted?
Subtypes with clinical features that can be predicted by autoantibody profile
What is myositis?
Autoimmune disease that causes muscle inflammation and weakness
What would you expect with Anti Jo-1 type dermatomyositis?
Fever
Myositis
Gottron’s papules
What would you expect with Anti SRP type dermatomyositis?
Necrotising myopathy
Dysphagia
What would you expect with Anti Mi-2 type dermatomyositis?
Mild muscle disease
What would you expect with Anti-p155/TIF1ɣ type dermatomyositis?
Associated with malignancy (in adults)
What would you expect with Anti-p140 type dermatomyositis?
juvenile, associated with calcinosis
What would you expect with Anti-SAE type dermatomyositis?
Amyopathic - no muscle weakness
What would you expect with Anti-MDA5 type dermatomyositis?
Interstitial lung disease
Digital ulcers/ischaemia
What might a dermatomyositis patient feature?
What are the investigations for dermatomyositis?
Blood tests incl. ANA, CK, LFTs
Skin biopsy
LFT (ALT often increased)
EMG
Muscle MRI
Screening for internal malignancy (e.g. CT CAP)
What is Henoch-Schonlein purpura?
IgA vasculitis
What would you get with Henoch-Schonlein purpura?
Macular purpura
Abdominal pain, bleeding
Arthralgia/arthritis
IgA associated glomerulonephritis (may develop later)
What are the investigations for IgA vasculitis?
Bloods
Urinalysis
Biopsy
Outline the types of small vessel vasculitis
Outline the types of small+medium vessel vasculitis
Outline the types of medium vessel vasculitis
Polyarteritis nodosa (PAN)
-Benign cutaneous form
-Systemic form
Outline the types of large vessel vasculitis
Temporal arteritis
Takayasu arteritis
What are the manifestations of small vessel vasculitis?
What are the medium vessel manifestations of vasculitis?
What is DRESS?
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
Severe, delayed hypersensitivity reaction to certain drugs, characterized by rash, haematological abnormalities, organ involvement, and systemic inflammation
What is the scoring criteria for DRESS?
Fever ≥ 38.5°C
Lymphadenopathy (lymph node swelling) ⩾ 2 sites, > 1cm
Circulating atypical lymphocytes
Peripheral hypereosinophilia
Internal organs involved - (liver, kidneys, cardiac)
Negative ANA, Hepatitis / mycoplasma, chlamydia
Skin involvement
What skin involvement would you see in DRESS?
> 50% BSA
Cutaneous eruption suggestive of DRESS
Biopsy suggestive of DRESS
What is the onset for DRESS?
2-6 weeks after exposure to drug
What internal organs are commonly affected in DRESS?
Liver most common internal organ involved – majority of deaths associated with this
Kidneys and cardiac system also commonly involved
What rash morphologies would you see in DRESS?
Urticated papular exanthem - widespread papules
Maculopapular (morbilliform) eruption
Widespread erythema (Erythroderma)
Head / neck oedema
Erythema multiforme-like
What is the treatment for DRESS?
Withdrawal of culprit
Corticosteroids are first line treatment - may require months of treatment
Mortality 5-10%
What is does itching without a rash suggest?
internal cause
What is pruritus?
A sense of itchiness/itching
What are the haematological causes of pruritus?
Lymphoma
Polycythaemia
Uraemia (due to renal failure)
What are the other causes of pruritus?
Cholestasis
Iron deficiency/overload
HIV, hepatitis A/B/C
Cancer
Drugs (NB opiates/opioids)
Psychogenic
Pruritus of old age
What are the investigations for a patient presenting with pruritus?
FBC, LDH
Renal profile
Liver function tests
Ferritin
XR Chest
HIV / Hepatitis A / B /C
What is nodular prurigo?
Hard, raised bumps that are extremely itchy, especially at night
Can interfere with sleep and quality of life
Likely caused by chronic scratching and rubbing of the skin
What is Stevens-Johnson syndrome?
Derm emergency! (Rare)
Extensive full thickness mucocutaneous (epidermal) necrosis <2-3 days
Caused by adverse reaction to a drug or infection
What is the most common cause of Stevens-Johnson syndrome?
Drugs > infection
What does untreated Stevens-Johnson syndrome lead to?
Toxic epidermal necrolysis (TEN)
Can be very lethal
Outline the progression of Stevens-Johnson syndrome
Prodromal: flu-like sx
Abrupt onset of lesions on trunk > face/limbs
Macules, blisters, erythema – atypical targetoid
Blisters merge – sheets of skin detachment ‘like wet wallpaper’
What are some differential diagnoses when considering TEN?
Staphylococcal scalded skin syndrome (SSSS)
Thermal burns
Cutaneous graft versus host disease
What is the pathology of TEN?
Cell-mediated cytotoxic reaction against epidermal cells
Drugs cause >80% of cases
May be started up to 3 weeks prior to onset of rash
What is used to assess the severity of TEN?
SCORTEN Criteria:
age >40
HR
initial % epidermal detachment
serum urea + glucose + bicarbonate
presence of malignancy
What are the complications of TEN?
Death - Overall mortality 30%
Blindness
dehydration
hypothermia/hyperthermia
renal tubular necrosis
eroded GI tract
interstitial pneumonitis
neutropenia
liver and heart failure
What is erythroderma?
Generalized erythema affecting >90% BSA
What is the significance of erythroderma?
Systemic manifestations reflect impairment in skin function:
-Peripheral eodema
- Tachycardia
- Loss of fluid and proteins
- Disturbances in thermoregulation
- Risk of sepsis
What are the possible aetiologies of erythroderma?
- Psoriasis
- Atopic eczema
- Drug reactions
- Cutaneous T-cell lymphoma – Sézary syndrome
- Idiopathic (25-30%)
What is the treatment/management for erythroderma?
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 temperature
Emollients to support skin barrier
+/- Topical steroids
+/- Antibiotics
