Teaching Clinic - Dermatological manifestations of systemic diseases Flashcards
- Dermatomyositis - SLE - Chronic painful nodules: panniculitis, medium vessel vasculitis +/- panniculitis - Erythema nodosum - Erythema induratum - Systemic sclerosis - Vascular diseases - Diabetes: acute manifestations and chronic skin disease - cutaneous manifestation of neoplasia - generalized pruritis of systemic disease
Dermatomyositis
Definition
Differentiation between polymyositis, dermatomyositis and amyopathic dermatomyositis
Dermatomyositis
Extent of muscle involvement
Dermatomyositis
Extent of cutaneous involvement
Dermatomyositis
Extra-cutaneous manifestations
Dermatomyositis
Clinical subsets, autoAb implicated in each clinical subset
Dermatomyositis
Investigations and diagnosis
Dermatomyositis
Management
Dermatomyositis
Commonly associated malignancies
Rule out NPC until proven otherwise
Name features
Heliotrope rash around eyelids
Gottron’s papules along downing line
Cuticle: small vessel dilatation/ telangiectasia
Cutaneous lupus erythematosus (CLE)
Differentiating features between acute, subacute and chronic CLE
Subacute cutaneous lupus erythematosus
Clinical features
Types:
Annular SCLE (urticarial-like eruption)
Papulosquamous SCLE (erythematous scaly plaques with psoriasiform appearance)
Toxic EM-like (Rowell’s syndrome)
Clinical features:
Highly photosensitive
Affected areas = sun-exposed aspects: face, V of neck, upper chest and upper back, shoulders, extensors of arms and forearms
Non-scarring
Scaly psoriasiform annular erythematous plaques and papules
Borders may show crusting, vesiculation
Follicular plugging and hyperkeratosis are not prominent
Name feature
Ddx
Annular SCLE (urticarial-like)
Name feature
Annular SCLE (urticarial-like)
Name feature
Ddx
Papulosquamous SCLE
Ddx:
Psoriasis
Lichen planus
Drug-induced SCLE
Common causative drugs
Cutaneous lupus erythematosus
Diagnosis
Diagnosis: mainly rely on clinical context
- Serum immune markers → Usually only anti-Ro/La, strongly a/w SCLE
- Skin bx at affected sites → lupus band test
Immunology:
- ANA+ in 70-80% of SCLE (ANA –ve can still be lupus)
- SCLE has a high prevalence of positivity to anti-Ro and anti-La: Anti-Ro is positive in 50-70%, especially the annular variant; Anti-La is positive in 30-40%
- Since anti-Ro autoantibodies are associated with Sjögren’s syndrome (dry eyes, dry mouth) as well as SCLE, some patients have features of both condition
Cutaneous lupus erythematosus
Management
Acute cutaneous lupus erythematosus
Subtypes
Clinical presentation
Ddx
Subacute cutaneous lupus erythematosus
Subtypes
Clinical presentation
Ddx
Chronic cutaneous lupus erythematosus
Subtypes
Clinical presentation
Ddx
Panniculitis
Definition
D/dx
Panniculitis
Histopathological classification
Subcutaneous fat lobule/septal wall
Look at vasculature structure: destroyed or not (vasculitis or not)
Septal panniculitis
Types with vasculitis and without vasculitis
Lobular panniculitis without vasculitis
Subtypes
Septal panniculitis without vasculitis/ Erythema nodosum
- Pathogenesis
- Causes
Erythema nodosum
Clinical presentation
Erythema nodosum
Investigation and diagnosis
Erythema nodosum
Treatment
Erythema induratum/ Lobular panniculitis with vasculitis
- Pathogenesis
- Clinical presentation
Erythema induratum
Investigation and diagnosis
Erythema induratum
Treatment
Chronic cutaneous lupus erythematosis: Discoid luous erythematosis
- Risk factors
Name feature
Discoird lupus lesion with dyspigmentation
Hypertrophic lesions develop with significant hyperkeratosis
Name feature
Discoid lupus erythematosus
Scarring alopecia
(always check beind ear for scarring alopecia)
Name feature
Lupus panniculitis: depressed area due to inflammatory lesion
Medium vessel vasculitis
Types with cutaneous involvement
Causes
Types:
- Polyarteritis nodosa: systemic necrotizing ANCA-negative vasculitis affecting medium-sized arteries
- Livedo vasculitis(cutaneous only)
Causes:
□ Idiopathic: majority
□ Secondary: streptococcal infection, HBV, HCV infection, IBD, hairy cell leukaemia
Medium vessel vasculitis/ Polyarteritis nodosa
Clinical features
Medium vessel vasculitis/ Polyarteritis nodosa
Diagnosis
Management
Name feature
Erythema nodosum
Panniculitis
History taking questions
P/E
Ix
Name feature
Cutaneous TB
Name feature
tuberculosis verrucosa cutis (TBC: direct inoculation of bacilli into skin, e.g. direct contact in swimming pool)
First line investigations for chronic recurrent painful nodules
Cutaneous manifestations of DM
Pathogenesis
Insulin and skin:
Insulin regulates glucose deposition into skin cells
Affects growth and differentiation of keratinocytes
promotes comedone formation
Affects dermal fibroblastic function and therefore dermal collagen formation
Cutaneous manifestations of DM
List all manifestations
Infections:
- Staphylococcal pyodermas
- Candidiasis
- Erythrasma
- Epidermophytosis
Xanthomatosis:
- Eruptive xanthomas
- Xanthelasma
- Tuberous xanothoma
Chronic degenerative changes
- Diabetic dermopathy
- Erythema and necrosis/ gangrene: rubeosis faciei (facial erythema)
- Bullous lesions
- Scleredema adultorum (of Buschke): skin induration in back and neck. Not painful, itchy.
- Thickened skin and stiff joints/ Skin and joint contactures
Other cutaneous conditions:
- Necrobiosis lipoidica diabeticorum (NLD)
- Granuloma annulare (GA)
- Acanthosis nigricans
- Perforating disease (Kyrle’s disease)
Cutaneous reaction to diabetic treatment
Name feature
Treatment
Name feature
Diabetic dermopathy = commonest cause of brown patch in LL in short case:
- Atrophic brownish patches in lower limbs
- Asymptomatic Appears and disappear over 12 to 18 months
- Constant appearances of new lesions, create a stationary impression
- Men/women: 2/1
- No telangiectasia/ yellow lesions
Name feature
Cause
Treatment
Necrobiosis lipoidica diabeticorum (NLD)
Clinical presentation:
Erythematous papules that coalesce into large plaques in the pretibial area
Yellow atrophic center with telangiectasia (can see through the macule)
Could be multiple
1/3 ulcerated
50% of DM cases have neuropathy or retinopathy
10-20% spontaneously resolution
Treatment:
?Benefit of tight control
Topical potent/ intralesional steroid
Antiplatelet agents (aspirin, dipyridamole)
Fibrinolytic therapy (nicotinic acid derivative)
Name feature
Treatment
Name feature
Causes
Acanthosis nigricans (AN: common):
- Papilloma with hyperpigmentation in axilla, inguinal, inframammary folds and neck
- Severe form could also involve the palms, sole and mucosal area
- Severe form linked to malignant disease
- Benign form associated with insulin resistance (hyperinsulinaemia) Insulin acts on IGF receptors
Other endocrinopathies associated:
- Acromegaly
- DM
- Obesity
- Cushing’s disease
- Polycystic ovary disease
Malignant:
- Lung, breast, uterus, ovarian, GI
- Associated with more extensive disease and could also involve the mucosa
- Associated with Leser-Trelat sign
Cutaneous reaction to DM treatment
Cutaneous manifestations of neoplasm
- Acanthosis nigricans
- Acquired icthyosis = extreme dryness of skin
- Amyloidosis
- Clubbing
- Coagulopathies/ bruising
- Cryoglobinemia
- Cushingoid features
- Dermatomyositis
- Erythema gyratum repens = annular rash that comes and goes
- Hypertrichosis lanuginose = increased hair growth, associated with CA pancreas
- Leser-Trelat = brownish plaque on face
- Pemphigus = associated with thymoma
- Necrolytic migratory erythema = also associated with CA pancreas
Generalized pruritis of systemic disease
Major Ddx
Causes
Need to ddx from
(1) scabies (tend to spare face)
(2) mild asteatotic eczema
(3) dermatographism
Causes:
- Thyroid disease
- Parathyroid diseases
- Hepatic disease especially obstructive jaundice
- Lymphoma
- Uraemia (e.g. DM)
- Iron deficiency
- Myeloproliferative diseases
Livedo reticularis caused by polyarteritis nodosa (medium vessel vasculitis)
Tender nodules, 5-10mm in diameter usually smaller than erythema nodosum
Dx and histology
Eryhema nodoum: septal panniculitis without vasculitis
Resolves into bruises
dx?
Varicose veins
Venous eczema (dry scaling itchy skin)
Erythrasma: superficial infection due to corynebacterium minutissimum
Wood lamp skin examination done: UVA radiation
Presents as well defined brownish patches in the intertriginuous areas (axilla, toe web)
Tx: 2 weeks course of erythromycin
Dx?
Diabetic dermopathy
Brownish papule and patches
No yellowish appearance
No blood vessels
