Derm - Skin in Systemic Disease Flashcards
Why is learning about skin in systemic disease important?
→ rash may be more than skin deep
→ prevent or reduce internal organ damage by early diagnosis
What are the 4 ways in which the skin can be involved in systemic disease?
→ skin is targeted by disease
→ skin provides signs of internal disorders
→ tell-tale skin conditions
→ systemic disease can be secondary to the skin disorder
What is a punch biopsy?
→ skin investigation done under local anaesthetic
→ sent for histology for analysis, etc.
What is Lupus Erythematosus?
autoimmune disease in which the immune system attacks its own tissues, causing widespread inflammation and tissue damage in the affected organs
What are the 2 main types of LE? Is there an overlap between them?
→ systemic LE
→ cutaneous (discoid) LE
→ yes, there is some overlap
What is the mucocutaneous diagnostic criteria of LE?
→ cutaneous lupus (acute) (ring-like plaques) → cutaneous lupus (chronic) → oral ulcers → alopecia (baldness) → chilblains → photo distributed (sun-exposed) rash → livedo reticularis → palpable purpura
What is the systemic or internal diagnostic criteria of LE
→ synovitis (inflamed joints)
→ serositis (serous tissue inflammation) (pleurisy or pericarditis)
→ renal disorder
→ neurological disorder
What is the haematological diagnostic criteria for LE?
→ haemolytic anemia
→ thrombocytopenia
→ leukopenia
What are the immunological findings in LE?
main : auto-antibodies → ANA → anti-dsDNA → anti-Sm → antiphospholipid → low complement → Direct Coomb's test
What is the significant presenting differences between the 2 types of LE?
→ Cutaneous / Discoid LE has more evident scarring
→ Systemic LE has more ring like plaques, etc.
What is neonatal lupus?
autoimmune disorder that is congenital
What are the presenting signs of neonatal lupus in a newborn?
→ ring-like rash / plaques
→ likely to be positive for Ro antibodies
What test should immediately be done for newborns w neonatal lupus? Why?
→ ECG
→ 50% risk of heart block
→ might need a pacemaker
What is dermatomyositis?
→ autoimmune connective tissue disorder
→ proximal extensor inflammatory myopathy
What are the presenting signs of dermatomyositis?
→ Gottron’s papules (plaques on the metacarpal + phalanges)
→ ragged cuticles
→ Shawl Sign (redness of upper back)
→ Heliotrope rash (erythema of the eyelids)
→ photosensitive erythema
What are the different subtypes of dermatomyositis classified by?
clinical features the can be predicted by autoantibody profile
What DM subtype presents with fever, myositis + Gottron’s papules?
Anti Jo-1
What DM subtype presents with necrotising myopathy?
Anti-SRP
What DM subtype presents with mild muscle disease?
Anti Mi-2
What DM subtype is associated with malignancy in adults?
Anti-p155
What DM subtype is juvenile and usually presents with calcinosis?
Anti-p140
What DM subtype presents with amyopathia (lack of muscle weakness)?
Anti-SAE
What DM subtype presents with interstitial lung disease, digital ulcers, ischaemia?
Anti-MDA5
What diagnostic tests need to be done for dermatomyositis?
→ antinuclear antibody test → creatine kinase (looking for increased CK) → skin biopsy → EMG → LFT (looking for increased ALT) → screening for internal malignancy
What are the symptoms of IgA vasculitis?
→ abdominal pain → bleeding → Henoch-Schonlein purpura → arthralgia → arthritis → IgA associated glomerulonephritis
What type of vasculitis presents systemically in the skin?
→ cutaneous small vessel vasculitis
→ benign cutaneous form of Polyartertis Nodosa (medium vessel vasculitis)
What are the different causes of cutaneous small vessel vasculitis?
→ idiopathic → malignancy → LE → infectious → medication exposure → inflammatory → IgA vasculitis → Urticarial vasculitis → acute haemorrhagic oedema of infancy
How do the small vessel manifestations of vasculitis usually present on skin?
purpura (macular or palpable)
How do the medium vessel manifestations of vasculitis usually present in skin?
→ digital necrosis
→ retiform purpura ulcers
→ subcutaneous nodules along blood vessels
What is sarcoidosis?
systemic granulomatous disorder of unknown origin
can affect multiple organs
most commonly affects lungs
How many have cutaneous manifestations of sarcoidosis?
33%
How does sarcoidosis present cutaneously?
→ highly variable
→ red-brown to violaceous papules on the face, lips, upper back, neck + extremities
→ can look like lupus pernio (nothing to do with lupus)
→ ulcerative
→ scar sarcoid
→ erythema nodosum (on the legs)
What does histology show for sarcoidosis?
non-caseating epthelioid granulomas
What is DRESS?
→ Drug reaction with Eosinophilia + Systemic Symptoms
→ rash + systemic upset incorporating haematological + solid-organ disturbances
→ underlying mechanism unknown
What is the diagnostic criteria for DRESS?
based on scoring criteria:
→ fever > 38.5
→ lymphadenopathy > 2 sites + more than 1 cm
→ circulating atypical lymphocytes
→ peripheral hypereosinophilia > 0.7 x 10 to the power of 9
→ internal organs involved
→ negative ANA, hepatitis, mycoplasma, chlamydia
→ skin involvement >
What internal organs can be involved in DRESS ?
→ liver (hepatitis)(most frequent) → kidneys (interstitial nephritis) → heart (myocarditis) → brain → thyroid → lungs (interstitial pneumonitis)
What is the onset of DRESS?
2-6 weeks after drug exposure
What drugs can trigger DRESS?
→ sulfoamides → anti-epileptics → allopurinol → Antibiotics → minocycline → ibuprofen
What is the cutaneous manifestation of DRESS?
rash: → urticated papular exanthem, (widespread papules) → maculopapular eruption → widespread erythema → head / neck oedema → erythema multiform-like
What is the treatment for DRESS?
→ withdrawal of drug
→ corticosteroids are first line
What is Graft versus Host Disease?
→ multiple organ disease
→ affects 10% of allogenic haematopoetic stem cell transplants
How can you differentiate between GvHD and rash induced by a drug?
→ face involvement
→ acral involvement
→ diarrhoea
What is pathogenesis of GvHD?
donor-derived T-lymphocyte activity against antigens in an immunocompromised recipient
What parts of the body does GvHD mainly affect?
→ skin
→ liver
→ GI tract
What is pruritus?
itching without a rash
What does pruritus suggest?
suggestive if internal cause: → haematological causes (lymphoma, polycythemia) → uraemia → cholestasis → iron deficiency → HIV or hepatitis A/B/C → cancer → drugs (opiates or opioids) → psychogenic → pruritus of old age
What investigations need to be carried for pruritus?
→ FBC → LDH → renal profile → liverfunction tetss → ferritin → chest x-ray → HIV → hepatitis A B C
What can develop as a result of pruritus?
nodular prurigo
What is nodular prurigo?
skin thickening as a defence mechanism due to excessive scratching
What is scurvy?
vitamin C deficiency
What are the cutaneous signs of scurvy?
→ spongy gingival with bleeding + erosion
→ petechiae, ecchymoses, follicular hyperkeratosis
→ corkscrew hairs with perifollicular haemorrhage
What is Kwashiorkor?
protein deficiency
What are the systemic features of Kwashiorkor?
→ hepatomegaly → bacterial or fungal infections → diarrhoea → loss of muscle mass → oedema → failure to thrive
What are the skin signs of Kwashiorkor?
→ superficial desquamation with large areas of erosion
→ sparse + dry hair
→ soft + thin nails
→ cheilitis (inflammation of lips)
What is the importance of zinc?
→ important role in 200 enzymes
→ regulates lips, proteins, nucleic acid synthesis
What are the causes of zinc deficiency?
→ congenital due to genetic (SLC39A4)
→ acquired
What is the Zinc deficiency triad?
→ Dermatitis
→ Depression
→ Diarrhoea
How does zinc deficiency manifest in the skin?
perioral + aural + perineal skin in particular is affected with scaly erosive erythema
What is the importance of Vitamin B3 in the body?
required for most cellular processes
What are the 4 D’s of Vitamin B3 (niacin) deficiency?
→ dermatitis
→ dementia
→ diarrhoea
→ death
What are the cutaneous manifestations of Vitamin B3 deficiency?
→ photo-distributed erythema
→ Casal’s necklace
→ painful fissures of the palms + soles
→ peri-anal, genital + perioral inflammation + erosions
What is carcinoid syndrome?
→ metastases of a malignant carcinoid tumour
→ results in 5-HT secretion
What are the main symptoms of the carcinoid syndrome?
→ hypotension
→ flushing
→ diarrhoea
→ bronchospasm
In how many cases of carcinoid syndrome do you see flushing?
25%
What is SJS/TEN?
→ Stevens-Johnson syndrome / Toxic Epidermal Necrolysis
→ Derm emergency
What are the symptoms + progression of SJS/TEN?
→ prodromal : flu-like symptoms
→ abrupt onset of lesions on trunk > face/limbs
→ macules, blisters, erythema - atypical taretoid
→ blisters merge to form sheets of skin detachment “like wet wallpaper”
Why is SJS/TEN considered an emergency?
extensive full thickness mucocutaneous (epidermal) necrosis (2-3 days)
Why is it called SJS/TEN?
it’s disease progression:
→ SJS = 10% BSA detachment
→ SJS / TEN = 1-30% BS detachment
→ TEN = more than 30%
What causes SJS/TEN?
→ cell-mediated cytotoxic reaction against epidermal cells
→ drugs cause >80% of cases
→ drugs must’ve started up to 3 weeks prior to onset
What drugs can cause SJS/TEN?
→ antibiotics → beta-lactams → sulphonamides → allopurinol → anti-epileptic drugs → phenytoin → carbamazepine → lamotrigine
What other diseases can SJS/TEN resemble?
→ staphylococcal scalded skin syndrome
→ thermal burns
→ cutaneous graft versus host disease
What is the diagnostic score criteria for SJS/TEN?
to help assess severity: → age > 40 → HR → initial % epidermal detachment → serum urea + glucose + bicarbonate → presence of malignancy
What are the complications of SJS/TEN?
→ death (overall mortality fo 30%) → blindness → dehydration → hypo or hyper thermia → renal tubular necrosis → eroded GI tract → interstitial pneumonitis → neutropaenia → liver → heart failure
What is erythroderma?
generalised erythema affecting >90% BSA
What are some of the systematic manifestations of erythroderma?
→ peripheral oedema → tachycardia → loss of fluids + proteins → disturbances in thermoregulation → risk of sepsis
What can cause erythroderma?
→ drug reactions → cutaneous T-cell lymphoma → psoriasis → atopic eczema → idiopathic
How can erythroderma be managed?
→ underlying cause (e.g. treat psoriasis, withdraw drug if drug is the cause etc.)
→ hospitalisation is necessary
→ restore fluid + electrolyte balance, circulatory status, body temp
→ emollients to support skin barrier
→ topical steroids
→ antibiotics
What are some of the skin manifestations of CKD?
→ excoriations
→ prurigo
→ xerosis (dryness)
→ half and half nails
→ calciphylaxis
→ cutaneous signs related to primary disease ( e.g. vasculitis, SLE)
→ cutaneous signs related to immunosuppression (e.g. viral warts, skin cancer)
What are some other signs of CKD?
→ anaemia
→ mucosal pallor
→ hair thinning
What are the skin manifestations of Chronic Liver Disease?
→ excoriations → prurigo → Clubbing → Jaundice → Spider Telangiectasia → Terry's nails → Meuhrcke's lines on nails → Palmar erythema → Porphyria cutaneous tarda
What is necrobiosis lipoidica?
plaques with red-brown raised edge with yellow-brown atrophic centre
What is the relationship between necrobiosis lipoidica and DM?
20-65% of cases occur in setting of Diabetes Mellitus
What is the treatment for necrobiosis lipoidica?
topical or intralesional steroids
What are other skin manifestations of Diabetes mellitus?
→ Terry's nails → Granuloma annulare → Neuropathic ulcers → Acanthosis Nigricans → xerosis (dryness) → xanthelesma or xanthomata → skin infections
How does Grave’s disease manifest in the skin?
pre-tibial myxoedema
How does Addison’s disease manifest in the skin?
hyper pigmentation
What endocrine disorders can have acne as a symptom?
→ acromegaly
→ Cushing’s syndrome
→ PCOS
What skin signs can acromegaly have?
cutis gyrata verticis
What are some skin manifestations of HIV?
→ severe seborrhoea dermatitis → extensive viral warts → CMV ulceration → eosinophilic folliculitis → bacillary angiomatosis → Norwegian scabies → severe psoriasis → morbilliform rash → urticaria → erythema multiforme → oral / genital ulceration → itch with no rash
What cutaneous diseases are associated with IBD?
→ Pyoderma gangrenosum → Orofacial granulomatosis → Panniculitis (erythema nodosum) → Aphthous ulceration → Association with psoriasis, pemphigoid
What cutaneous diseases are associated with celiac disease?
dermatitis herpetiformis
What is hidrandenitis suppuritiva?
causes small, painful lumps to form under the skin
What are the symptoms of hidrandenitis suppurtiva?
→ Inflamed nodes → sterile abscess → sinus tracts → fistulae → hypertrophic scars
What areas does hidradenitis suppurtiva usually occur in?
Favours intertriginous zones (areas that rub together) : especially axillary, anogenital and inframammary area
What are other consequences of hidradenitis suppurtiva?
→ pain
→ bad body odour
What are risk factors for HS?
→ high Dmi
→ diabetes
→ IBD
What is pyoderma gangrenous?
→ causes large, painful sores (ulcers) to develop on your skin
→ pustule on an erythematous base - ulcerates + extends with necrotic undermined border
What systemic disease is pyoderma gangrenous associated with?
in 50-70% of cases:
→ IBD
→ leukaemia
→ seronegative arthritis
What are some of the ways in which internal malignancy can present cutaneously?
→ cutaneous metastases
→ malignancy reflecting internal malignancy
→ genetic condition predisposing to internal cancer + skin lesions
→ skin disease associated with malignancy
→ non-specific skin disease
What are some non-specific skin disease that could mean internal malignancy?
→ pruritus
→ vasculitis
→ urticaria (hives)
What is urticaria?
hives
What skin disease are associated with malignancy?
→ dermatomyositis
→ erythema gyratum repens
→ pyoderma gangrenosum
→ paraneoplastic pemphigus
What is paraneoplastic pemphigus?
fatal autoimmune blistering disease associated with malignancy
What is pyoderma gangrenosum?
large, painful sores (ulcers) to develop on your skin, most often on your legs
What is erythema gyratum repens?
rare disease characterized by the cutaneous eruption of migratory concentric erythematous bands
What is an example of cutaneous malignant reflection of internal malignancy?
extramammary Paget’s disease
What are some genetic conditions that predispose to internal cancer + skin lesions?
→ hereditary leiomyomatosis
→ renal cell cancer
→ Peutz-Jeghers syndrome
What is Paget’ disease?
disease of bone interferes with your body’s normal recycling process, in which new bone tissue gradually replaces old bone tissue
What is acanthuses nigricans?
skin condition that causes a dark discoloration in body folds and creases
