Blisters, Pruritus and Rashes due to Systemic Condn Flashcards
What is erythema nodusum
Skin condn where red, tender nodules forms on the skins and less commonly the thighs and forearms
What can eryhema nodusum be classified as
A type of panniculitis - infl disorder affecting s/c fat
Epidemiology of erythema nodusum
Ages 20-45, peak 20-30
3-6x more common in F than M
Often associated w/ recent illness or infection
Causes of erythema nodosum
NODOSUM
No - idiopathic D - drugs O - OCP/ pregnancy S - sarcoidosis U - ulcerative colitis (IBD)/ Crohns Micro
Drugs causing erythema nodosum
Sulphonamides Salicylates NSAIDs Dapsone Bromides Gold salts
Micro (pathogens) casing erythema nododum
TB
Strep
Toxoplasmosis
Px of erythema nodosum
Sx of underlying disease
2-50 red lumps
Fever, joint pain and feeling unwell
Natural hx of erythema nodosum
Hot and painful, bright red when first appears
Later becomes purple and fades through colour changes of a bruise
Dx of erythema nodosum
Throat swab Sputum ot gastric washing FBC, ESR, CRP ASO titre (strep) CXR (TB and sarcoidosis)
What is cutaneous vasculitis
Group of disorder in which there are inflamed blood vessels in the skin
Skin changes in cutaneous vasculitis
Capilaritis
Pigmented purpura
Characterised bu petechiae resolving w/ haemosiderin deposition
What skin changes are typiccalya associated w/ small vessel vasculitis
Palpabal epurpura
What skin changes are medium vasculitis usually associated w/
Nodules
Livedo reticularis
Causes of cutaneous vasculitis
Infection CTD Malignant Drugs - abx Idiopathic - IgA vasculitis (HSP)
CTD causing cutaneous vasculitis
SLE and related condns RhA SScl Sjorgen Dermatomyositis
Malignancy causing cutaneous vasculitis
Haematological
Myleoproliferative
Lymphoma
Myeloma and MGUS
Dx of cutaneous vasculitis
Clinical picture
Skin bx
Screening for underlying
Pyoderma gangerosum
Condn causing rapid;y enlarging, very painful ulcers
Feature of pyoderma gangrenosum
Ragged
Purple
Undermined edge
Causes of pyoderma gangrenosum
IBD Myeloproliferative disease RhA Drugs Monoclonal gammopathy Idiopathic
Dx of pyoderma gangrenosum
Clinical picture Swabs Bx to excl other causes of ulcer Associated systemic disease Response bro oral steroids
Necrobiosis lipoidica
Granulomatous skin disorder which can affect skin of insulin dependent diabetics, although it can occur in non diabetic subjects as well
Features of necrobiosis lipoidica
Tender, yellowish, brown patches develop slowly on the lower legs over several months
Slow healing
How do the patches in necrobiosis lipoidoca change over time
Round, oval or an irregular shape
Centre of patch becomes shiny, pale, thinned w/ prominent blood vessels (telangiectasia)
What can a minor injury to an established lesion in necrobiosis lipoidica cause
Ulceration of the lesion
What can localised granuloma annulare be associated with
Autoimmune thyroiditis
What can extensive GA be associated with
DM, hyperlipidaemia
More rarely w/ lymphoma, HIV infection and solid tumours
What type of GA is most common in children
Localised
What type of GA presents in adults
Generalised
Px of generalised GA
Widespread skin-coloured, pinkish or slightly mauve-coloured patches
DIssemnated type is composed of small papules
What is erythema multiforme
A HS reaction usually triggered by infections, most commonly HSV
Usually a/c and self-limiting
Px of erythema multifrome
Target-like lesions
May be mucous membrane involvement
What can erythema multiform be divide dinto
Major and minor forms
Causes of erythema multiforme
Viral infection
Drugs
Viral infection causing erythema multiform
Para poxvirus VZV Adenovirus Hepatitis HIV CMV Viral vaccine
Drugs causing erythema multiforme
Barbituates NSAIDs Penicillin Sulphonamides Phenothiazines Anticonvulsnats
Dx of erythema multiforme
Clinical dx
Skin bx
Screen for underlying cause
Xathoma
Skin lesions caused by accumulation of fat in macrophages in the skin and rarely s/c layer of skin
What might xanthoma be indicative fo
Lipid metabolism holism disorders
Congenital conditions causing xanthomas
Primary billiard cirrhosis (autoimmune)
Familial hyperlipidamie
May also be idiopathic
Acquired causes of xanthoma
DM
Cholestasis
Hypothyroidism
C/c renal failure
How are xanthoma classified
According to where they re found on the body and how they develop e.g. palmar xanthoma, tendon xanthoma, xanthelasma
Causes of eruptive xanthoma
Familial triglyceridaemia
Lipoprotein lipase deficiency
Xanthelesma palpebrum
Most common type of xanthoma, arise symmetrically on upper and lower eyelids
May or may not be associated w/ hyperlipidaemia
Tuberuous xanthoma
Firm, painless, red-yellow nodules that develop around the pressure areas such as knees, elbows, heels and buttocks
What is tuberous xanthoma usually associated w/
Hypercholesterolaemia
Tendinous xanthoma
Slowly, enlarging s/c nodules related to a tendon or ligament
What is tendinous xanthoma associated w/
Severe hypercholesterolaemia and elevated LDL levels
What is eruptive xanthoma seen in
DM pts
What areas of the body are affected by eruption;tive xanthoma
Buttocks
Shoulder
Arms - extensor aspect
What does xanthoma disseminatum affect
Internal organs
Self-limiting
Skin changes during pregnancy
Striae Skin tags Changes in hair growth Acne breakouts Spider veins and VV Darkening of areas of your skin Darkening of moles and freckles
When does pruritic urticariated papules and plaques of pregnancy occur
3rd trimester of primiparous women
Primiparous
Women who have been pregnant and given birth
Features of pruritic, urticraiated papules and plaques of pregnancy
Doesn’t recur w/ future pregnancies
Spares umbilicus
Treatment of pruritic, urticariated papules and plaques of pregnancy
Topical steroids
Antihistamines
Do pruritic urticated papules and plaques of pregnancy pose a risk to newborn
No
Pemphigoid gestations
Abrupt onset of urticarial plaques and blisters usually in 2nd trimester
Features of pemphigoid gestations
Recurs in future
Takes weeks-months to resolve postpartum
Histologically similar to bullies pemphigoid (C3, IgG)
Treatment of pemphigoid gestations
Oral steroids
Intrahepatic cholestatis of pregnancy (ICP) presentation
Pruritus (palms and soles)
Dark urine
Jaundice
When does Intrahepatic cholestatis of pregnancy px
2nd or 3rd trimester
Does Intrahepatic cholestatis of pregnancy resolve on delivery
Yes
Does Intrahepatic cholestatis of pregnancy carry any risks to the newborn
Yes - higher risk of premature or stillbirth
Pathology of Intrahepatic cholestatis of pregnancy
Bile acids from liver unable to flow properly and build up in the body
Treatment of ICP
Urseodeoxycholic acid
Neurophyiology of pruritus
Complex and not fully understood
Itch transmitted by C fibres
Spinothalamic tracts –> thalamus —> sensory cortex
Differntials of generalised itch w/out rash
Renal pruritus Cholestatic pruritus Endocrine - thyroid, DM Paraneoplastic Haematological HIV Pregnancy related Drug related
Ddx of generalised itch w/ rash
Scabies Eczema Urticaria/ dermographism Paraneoplastic Bullous disease Psoriases - main cause Pregnancy related Drug eruptions
Who is renal pruritus seen in
Seen in pst w/ c/c renal failure (mainly advanced)
Peaks 2nd nights w/out dialysis,
Mx of renal pruritus
Improves after dialysis
Subtotal parthyroidectomy
Phototherapy and antihistamines
Is renal pruritus dependent on raised serum urea
No
When does cholestatic pruritus occur
In any liver disease - usually intrahepatic cholestasis
Where is cholestatic worse
Worse on hands, feet and body and body regions constricted by clothing
Also worse at night
Treatment of cholestatic pruritus
Treat underling cause
Dugs - cholestyramine, ursodeoxycholic acid, rifampicin
MOA of cholestyramine
Binds to bile acids preventing re-absorption
MOA of ursodeoxycholic acid
Regulates cholesterol via absorption rates
Enodrcine causes of pruritus
Thyroid disease - more h-common in hyper > hypo
DM - associated w/ poor glycaemic control, can be part of diabetic neuropathy
May also be candida infection in DM pts
Haematological causes of pruritus
IDA
Haemochromatosis
PV - aquagenic
CLL
HIV asd a cause of pruritus
Can px w/ generalised itch
Secondary dermatoses are more common: candidiasis, Kaposi sarcoma, 2’ to lymphoma, eosinophilic folliculitis, drug reaction
Infections seen in hIV pts causing itch
Hepatitis A, B, C, E
Swimmer’s itch
Helminths
Skin involvement in cutaneous T-cell lymphoma
Mycosis fungicides
Dry, peeling, itchy skin
Erythroderma
Thickened skin on sole and palms
Rashes due to scratching
Excoriation
Nodular prurigo - butterfly sign
Lichen simples chronic - caused by constant rubbing and scratching
Butterfly sign in nodular prurigo
No lesions on back where pt cannot reach
Tyepes of cutaneous drug reaction
Exanthematous Pustular Urticaria, angiodema, anaphylaxis Fixed drug eruption Drug HS syndrome Pigmentation Pseudoprohyria Necrosis
Types of blisters (sizing)
Bullae - >0.5cm elevated circumscribed fluid filled sac
Vesicles - <0.5cm elevated circumscribed fluid filled sac
Hx for drug-induced rashes
Sites e.g. single dermatome, where cream apples, light exposed areas
Onset & timing e.g. insect bite, had this before
Charters
Exacerbating 7 relieving factors
Any recent illness
Any new exposures
Allergies
How does erythema multiforme start
Target plaques and papules predominantly starts aurally distributed
Features of Erythema multiforme major
Major has fever & >1 mm involved (mouth, eye, genitals, GI tract/ anus, trachea/ bronchi)
SJS
Steven Johnsons Syndrome
TEN
Toxic Epidermal Necrolysis
SJS and TEN
Macules or blisters developing into sheets of skin detachment
SJS: 10-30%
TEN: >30%
Typically associated w/ prodormoal illness
Drugs that may cause a reaction —-> SJS/ TEN
Sulphonamides Imidiazole Naproxen Ibuprofen Anticonvsulanst e.g carbamazepine, phenytoin, valproic acid
+ve Nikolsky sign
Rubbing red skin then formation of blisters
How is SJS/TEN graded
SCORTEN
7 parameters of disease severity used to predict in-hosp mortality
When do pustular drug orectaiosn start
1-3 week(s) after drug
May cause desquamation after initial reaction
Where do pustular drug reactions occur
Face
Flexures
Ix findings of pustular drug reactions
Raised neutrophils
Sterile pus
When do pustular drug reactions resolve
<15 days
Features of fixed drug eruption
Solitary erythematous plaques, bullae or erosion
Occurs 30mins - 8hrs
If exposed to same drugs –> same site in hrs
Area becomes hyper pigmented
When do fixed drug eruption resolve
In a few weeks
When does drug hypersensitivity syndrome occur
2/12 later
What does DRESS syndrome consist of
Drug rash
Eosinophilia
Systemic sx
DRESS px
Fever
Papaules, facial oedema +/- exfoliative dermatitis
Lymphadenopathy
Haematological findings in DRESS
Eosinophilia
Atypical lymphocytes
Organ involvement in DRESS
Hepatitis
Carditis
Interstitial nephritis
Interstitial pneumonitis
Causes of drug-induced pigmentation
Amiodarone - slate grey
Antimalarial (>4/12) - brown or blue-black
Oestrogen/ progesterone - hyperpigmneted patches (melasma)
Drug related necrosis and warfarin
Seen days 3-5
Prone if hereditary deficiency of protein C. S or antithrombin III
Px of pseudoporphyria
Photosensitive, bulbous rash on hands and feet
Features of pseudoporphyria
Heals w/ scars and milia
Histologically different from porphyria & porphyrin studies are -ve
Drug reaction mimics of pemphigus vulgaris
Captopril
P;eniclllamine
Ampicillin
Drug reactions mimics of bullous pemphigoid
Furosemide Bumetanide Spiro Penicillamine Amoxi Cipro
Drug reaction mimics of lineal IgA disease
Vancomycin
Ix for drug induced rashes
Blood tests - akin autoimmune, raised IgE, serum + blister fluid IMF
Swab - viral, bacterial
Bx
What are welling for when we perform a bx for blisters
Levl of split - sub-corneal, into-epidermal & sub-epidermal
What is depositing at that layer e.g. IgA, IgG, C3
IMF as an ix for blistering disorders
Determines which layer of the basement membrane is splitting e.g. desmosome for pemphigus
Which layer of skin are the blisters in pemphigus vulgaris found
Within the epidermis floor, lined by basal cells
What types of cells are found in blister fluid for pemphigus vulgaris
Acantholytic
Which layer of skin are the blisters in pemphigoid found
Sub epidermal
Which layer are the blisters in dermatitis herpetiformis found
Sub epidermal
Infiltrates in underlying dermis for pemphigoid vs dermatitis herpetiformis
Eosinophil for pemphigoid
Neutrophil fro dermatitis herpetiformis
IMF results for diff blistering disorders
Intercellular IgG & C3 - pemphigus
Basement membrane IgG & C3 - pemphigoid
Dermal papillary IgA - DH
Mx for drug-induced rashes
Stop drug
Antihistamine (sedating)
Steroids - top or po
Mx for drug-induced rashes causing anaphylaxis
CHAOS
Chlorphenamine IM/IV Hydrocortisone IM/ IV Adrenaline Oxygen Salbutamol IV fluids
Exanthematous drug rectaion
Measles-like rash (morbilliform, maculopapular)
EBV + amoxi or ampicillin = rash
3-5 darts after stopping drug
Examples of blistering disorders
Bullous pemphigoid
Pemphigus vulgarise
Dermatitis herpetiformis
Types of blisters (level of split)
Sub-epidermal
Intra-epidermal
Where is the basement membrane found
Interface between dermis and epidermis
Features of blisters in pemphigoid
Thick walled and tense
Occur at hemidesmosome
Features of blisters in pemphigus
Thin walled and flaccid
Occur at desmosome
Epidemiology of pemphigoid
Acquired blistering disease
Most common autoimmune bullouse disease
Peak incidence 8th decade
Hx of pts w/ pemphigoid
Itchy rash - weeks to months
Blisters
Examination of pts w/ pemphigoid
Eczematous or urticariated rash
Tense blisters (vesicles and bullae)
Localised or widespread
Mucous membrane involvement 1/3 - 1/2
Difference in distribution of lesions in PV and pemphigoid
Pemphigoid is more likely to a facet limbs
Ix for pemphigoid
Bx - histology, direct IMF indirect IF (circulating bp abs in 70%)
What kind of sample needs to be taken for pemphigoid IMF
Perilesional skin - band of IgG +/- C3 along bm
Treatment for pemphigoid
Orla steroids (30-40mg) (+bisphosphonates, PPi)
May use doxycycline
Nicotinamine
+/- azathioprine
Why may doxycycline be used in pemphigoid
Steroid-sparing agent for anti-infl
Prognosis of pemphigoid
Pt relapse/ remitting
Can last for 5 yrs
Morbidity/ mortality related to treatment
Pathogenesis of pemphigus vulgaris
Acquired autoimmune blisters
IgG to desmosomal antigens
Target = demsoglein 3, codes for cadherin
Hx of pts w/ pemphigus
Age 40-60 yrs (median 7th decade)
Oral ulcers - preceding rash (months)
“Sore” rash rather than itchy
Examination features of pemphigus
Mouth ulcers
Erosion of skin
Fragile/ flaccid blisters
+/- involvement of other mms
Mm involvement seen in pemphigus
Laryngeal Pharyngeal Nasal Oesophageal Urethral Vulval
Mucosal surfaces erosions seen rather than bullae
Sites of pemphigus vulgaris
Scalp Face Chest Axillae Groin Umbilicus Back if bed ridden
Acantholysis
Loss of normal cell-cell adhesion
Direct IMF for PV
‘Chicken wire’ or ‘crazy paving appearnce’
Ix for PV
Bx - histology (intra-epidermal split), direct IMF, acantholysis
Indirect IF
Titre proportional to activity
Treatment of PV
High dose oral steroids
Azathioprine
Plasmapheresis
IV Ig
Prognosis of PV
Mortality of 5-15%. Associated w/ tx, infection, fluid and electrolyte imbalance
Rare variants of PV
Follaceous
Paraneoplastic
Features of follaceous PV
Desmoglein antibody causes upper epidermal pacantholysis, not mms
Benign course
Where does follaceous PV present
Scalp, face, chest, upper back - similar distribution as Seb K
What do pt’s dermatitis herpetiformis also have
Gluten sensitive enteropathy (coeliac) - usually 2’ gluten enterooptahy
What is dermatitis herpetiformis associated w/
Other autoimmune condns - DM, thyroid, pernicious anaemia, SLE
Pathogenesis of dermatitis herpetiformis
Deposition of IgA and epidermal transglutaminase complexes in the papillary dermis
Hx of pts w/ DH
Age of onset 20-60 Have an intensely, itchy rash Small blisters (herpetiform) - vesicles
Examination of pts w/ DH
Erythematous papules + blisters Excoriations Extensor aspects - knees, elbows, buttocks (grouped vesicles) May be more widespread MM not involved
Ix for DH
Bx Histology - sub-epidermal Direct IMF (sample from uninvolved skin) Indirect IMF for skin autoantibodies Distal duodenal bx Antiendomysial and tTG (+ve)
Direct IMF results for DH
Granular deposits IgA in dermal papillae
Treatment of DH
Gluten free diet - rash resolves after 2-3yrs on diet
Dapsone
Sulphonamides
Dapsone side effects
Headaches Depression Lethargy Haemolytic anaemia - severe in G6PD deficiency Neuropathy
What needs to be checked before prescribing dapsone
G6PD levels for deficiency
Sulphonamides side effects
Bone marrow suppression (esp neutrophils) Nausea Depression Rashes Hepatitis Interstitial pneumonitis
Azathioprine side effects
GI disturbance - nausea, vomiting, diarrhoea
Bone marrow suppression
Liver damage
Blood tests to monitor azathioprine
LFT
FBC
U&E
Prurigo of pregnancy
Discrete erythematous or skin coloured papules, excoriated
Occurs in any stage of pregnancy
Treatment of prurigo of pregnancy
MInld to moderate steroids
1% menthol in aq cream arm
Antihistamines
Which antihistamines should be used in prurigo of pregnancy
Cetirizine
Loratidine
What level of the skin does UVA rays reach
Dermis
Causes skin damage e by damage to the dermis
Which level of the skin do UVB rays reach
Absorbed by the epidermis
Causes erythema, oedema and skin ageing
Which form of UV radiation is responsible for Vit D synthesis
UVB
Also more potent than UVA
Fitzpatrick I features
Burns easily, never tans
Ivory/ white
Fitzpatrick II features
Burns easily, tans minimally w/ difficulty
White
Fitzpatrick III features
Burns moderately, tans moderately and uniformly
Beige
Fitzpatrick IV features
Rarely burns, tans profusely
Light brown
Fitzpatrick V features
Never burns, tans profusely
Dark brown
Factors increasing incidence of sunburn
Regions situated closer to the equator Areas at high altitude Skin exposure between 10am - 2pm Clear skies Envirpnemnetal reflection (from snow and ice)
Things to look out for in examination of pits w/ photosensitive skin disease
Sparing fo facial creases, behind ears, lower eyelids, beneath nose and chin
Erythema, blisters, wheals
How can we group photosensitive disease
Idiopathic Genetic Metabolic Autoimune Exogenous Other diseases that a re exacerbated by sunlight
Pathogenesis of sunburn
Erythema and vasodilation of skin caused by excess exposure to UV(B)
UVB releases chemicals making skin tender, hot, blistering
What chemicals are released by UIVB isn sunburn
Leukotrienes
NO
Histamines
PGE2
Features of severe sunburn
Blistering Dehydration Infection Electrolyte imbalance Shock
What is sunburn typically followed by
Desquamation and pigmentation
Long term consequences of sunburn
Increased risk of skin cancer
Lentigo formation
Skin ageing
Polymorphic light eruption
Itchy, erythematous eruption
Spares habitually exposed ares (face, hands)
‘Prickly heat’
Pathology behind polymorphic light eruption
Autoimmune infl response if the skin to UV radiation
Mx of polymorphic light eruption
Avoidance/ sunblock
If severe, steroids (po or top)
Prophylactic UVB/ UVA
Ddx of polymorphic light eruption
Lupus erythematous
Px of c/c actinic dermatitis
Pruritic, erythematous, thickened xeroderma
Sun exposed skin
Often hx of pre-existing eczema
Dx of c/c actinic dermatitis
Patch testing
Photo patch testing
Epidemiology of c/c actinic dermatitis
Men > 50
Mx of c/c actinic dermatitis
Sun avoidance/ sun block
As for eczema (emollient, top steroids)
Solar urticaria
Rare, physical urticaria within mins of UV light, lasts a few hrs
Px of solar urticaria
Raised, erythematous wheals
Mx of solar urticaria
Sun protection
Antihistamine
Desensitising phototherapy
Actinic prurigo
Photosensitivity causing v itchy papules on sun exposed areas
Epidemiology of actinic prurigo
Usually children <10
More common in darker skin types
Often over lips and sun exposed ares on face - worse in spring/ summer
Mx of actinic prurigo
Emollients
Topical steroids
Hydroxychloroquine
Desensitisation
Hydroa vacciniforme
Blisters form over sun exposed ares and heal w/ scarring 30-120 mins after exposure
Causes burning sensation or itching
Epidemiology of Hydroa vacciniforme
Children aged 3-15,
F>M
Resolves once teenagers, but left w/ scarring
Mx of hydrovacciniforme
Sun protection/ avoidance
Desemnistising phtotheroay
Rarely, hydroxychloroquine
Xeroderma pigmentosum
Rare, autosomal recessive defect in DNA repair
Results in photosensitivity, skin ageing tendency to form skin cancer
What may xeroderma pigmentosum be associated w/
Neurological or ocular disease
Mx of xeroderma pigmentsoum
Sun avoidance/ protection
Regular skin examination
Px of Porphyria Cutanea Tarda
Erythema, blisters, erosions, hypertrichosis
Often over hands, face, neck, chest
What are the skin changes in PCT in response to
UV
Radiation
Minor trauma
Triggers of PCT
Alcohol
Oestrogen (cocp, liver disease, HRT)
Iron overload (oral iron/transfusions, hepatitis, haemochromatosis)
These all increase the production of porphyrins
Ix for PCT
Bx Urinary porphyrins Woods light (fluoresces coral pink) Check Hb, Fe, LFTs, viral hepatitis screen Fasting blood glucose ANA
Mx of PCT
Avoid alcohol, oestrogen, iron
Sunblock/ sun avoidance
Venesection if necessary
Rarely, hydroxychloroquine
What does cutaneous LE px with
Mlar (butterfly) rash Photosensitivity Mouth ulcers Urticaria Hair thinning
Classification of Lupus Erythematosus
Cutaneous LE
Systemic LE
Drug-induced LE
Aside from the skin, what may systemic LE also affect
Joints Kidneys Lungs Heart Liver Blood vessels (vasculitis)
May be associated w/ aPL antibodies
Which drugs can cause drug-induced LE
Hydralazine Carbamazepine Lithium Phenytoin Sulphonamides Minocycline
Ix for LE
FBC U+Es ANA Anti-dsDNA Anti-Ro/La aPLs Skin bx w/ IMF
Mx of LE
Stop causative drugs Smoking cessation Sun protection/ avoidance Topical steroids Oral steroids Immunosuppression
Phytophotodermatitis
Form of plant dermatitis
Reaction to organic psoralens found in lime, celery, wild carrot, hogweed
Subsequent exposure to sunlight causes irregular erythema and blistering
What are examples of conditions exacerbated by the sun
Darier’s
HSV
Pellagra
Photoaggravated psoriasis
Pellagra
Deficiency in niacin
Causes diarrhoea, dermatitis and dementia
What are examples of conditions that improve following sun exposure
Atopic eczema Pityriasis lichenoides Pityriasis rosea Psoriasis Pruritus/ of renal failure and liver disease
What is purpura
Non blanching rash due to haemorrhage from skin vessels
Macular vs palpable purpura
Macular is usually non-infl
Palpable purpura is usually infl (e.g. vasculitis)
Causes of purpura
Platelet disorders
Vascular disorders
Coagulation disorder
Platelet disorders as a cause of purpura
TTP - usually causes petechiae
Vascular disorders as a cause of purpura
Blood vessel wall damage (vasculitis) - may be palpable
Deficient vascular support
Schamberg’s disease
Deficiente vascular support as a cause of purpura
Senile purpura
Corticosteroid-induced
Features of Schamberg’s disease
Brown macule
Red, cayenne pepper spots on legs
Coagulation disorders as a cause of prpura
DIC, HIT, warfarin induced necrosis
Usually causes ecchymoses & external bleeding
Non-palpable purpura causes - petechiae
Thrombocytopenia
Abnormal platelet function
Increased intravascular venous pressures
Some infl skin diseases
Non-palpable purpura causes - echymoses
External trauma DIC and infection Coagulation defects Skin weakness/ fragility Waldenstrom hypergammaglobulinaemia
Does systemic vasculitis alway have cutaneous features
No
Causes of vasculitis
Idiopathic Infection Infl and autoimmune diseases Drugs Neoplastic
What types of vasculitis can be caused by infection
Henoch-Schonlein Purpura
Septic vasculitis
Infl and autoimmune disease causing vasculitis
SLE, RhA, Crohn’s, UC
Rare causes - Churg-Strauss, Wegener’s granulomatosis, polyarteritis nodosa (PAN)
Drugs that may cause vasculitis
Sulphonamides Beta-lactams Penicillin Quinolones NSAIDs OCP Thiazides
Neoplastic causes of vasculitis
Paraproteinaemia Lymphoproliferative disorders (lymphoma, leukaemias)
Infections causing vasculitis
Can be any infection - often follows URTI
Bacterial esp meningocuus
Viral - hep B & C
Pattern seen in Henoch-Schonlein Purpura (IgA)
Skin vasculitis
Joint pain
Abdo pain
Presence of IgA
What type of vasculitis is livedo reticularis seen in
PAN
Anti-cardiolipin antibodies or cholesterol emboli
Examples of large vessel vasculitis
Temporal/ GCA
Takayasu’ arteritis
Examples of medium vessel vasculitis
PAN
Kawasaki disease
Examples of small vessel vasculitis
Granulomatous vasculitis
Microscopic polyangitis (polyarteritis)
HSP (IgA)
Examples of granulomatous vasculitis
Wegener granulomatosis
Churg-Strauss syndrome
Cutaneous px of larger vessel vasculitis
Claudication
Ulceration
Necrosis
Cutaneous px of small-medium vessel vasculitis
S/c nodules
Purpura
Fixed livedo reticularis
Cutaneous px of small vessel vasculitis
Palpable purpura
Rarely, urticarial lesions (urticarial vasculitis)
Systemic manifestations of GCA
Associated w/ PMR
Headache
Jaw claudication
Blindness (amaurosis fugax)
Cutaneous involvement of GCA
Tender, swollen, nodular indurated temporal artery
Epidemiology of Takayasu arteritis
Usually occur in young women and Asian population
Features of Takayasu;s arteritis
Typically affects aorta and branches:
Unequal BP in upper limbs
Claudiaction on exertion
Renal artery stenosis
Mx of Takayasu’s arteritis
Steroids
Epidemiology of PAN
More common in middle-aged men and its associated w/ Her B infections
Features of PAN
Livedo reticularis Fever, malaise, arthralgi HTN Renal disease - haemoturia Microaneurysm on angio* Neuritis
Cutaneous features of PAN
5-10mm s/c nodules distributed segmentally
May be painful, pulsatile or secondly ulcerated
Kawasaki disease epidemiology
Seen in children
Features of Kawasaki disease
High grade fever for at least 5/7 Bright red, cracked lips Strawberry tongue Cervical lymphadenopathy Polymorphic rash followed by desquamation of palms and soles
Prognosis of Kawasaki disease
Most cases are benign but risk of coronary artery aneurysms
Mx of Kawasaki disease
High dose aspirin
IV Ig
Echo - screen for aneurysms
Epidemiology of HSP
Most common in children <10
Can be triggered by URTI
Pathogenesis of HSP
IgA deposition in vessel walls
Cutaneous features of HSP
Symettricla, intermittent palpable purpura over buttocks and extensor extremities
Systemic features of HSP
Abdo pain
Haematuria
Arthralgia
Prognosis of HSP
Very good - eps in children
BP and urinalysis monitored to detect renal involvement
Wegener’s granulomatosis (granulomatosis w/ polyangitis)
Necrotising granulomatous infl of upper and lower resp tract
Resp features of Wegener’s granulomatosis
Epistaxis
Sinusitis
Haemoptysis
Systemic features of Wegner’s granulomatosis
URT/LRT involvement
Glomerulonephritis
Saddle-shop nose deformity
Cutaneous features of Wegener’s granulomatosis
Painful, s/c nodules
Pyoderma gangrenous lesion
Palpable puerperal
Churg0Strauss syndrome (eosinophilic granulomatosis w/ polyangitis)
Triad of tissue eosinophilia, granulomatous inflammation and vasculitis
Features of Churg-Strauss
Asthma and allergic rhiniti9s - typically precedes vasculitis phase
C/c sinusitis
Mononerutos multiplex
Blood eosinophilia
Cutaneous stigmata of Churg-Struass
Palpable purpura
Infiltrated nodules
Mx of Churg-Strauss syndrome
Steroids
Pathophysiology of cutaneous leukocytoclastic vasculitis
Circulating immune complexes deposited in walls of affect small vessels/ post-capillary venules in dermis
Epidemiology of cutaneous leukocytoclastic vasculitis
F > M (2.5: 1)
Skin lesions in cutaneous leukocytoclastic vasculitis
Palpable purpura on ankles/ LL or pressure points
Urticaria or ulcers possible
ANCA associated vasculitis
Wegners (cANCA)
Churg-Strauss (pANCA)
Microscopic polyarteritis (pANCA)
Which vasculidities show low levels of complement
Mixed cryoglobulinaemia
Urticarial vasculitis
Lupus
