Teaching Clinic - Dermatological manifestations of systemic diseases

Question 1

Dermatomyositis

Definition
Differentiation between polymyositis, dermatomyositis and amyopathic dermatomyositis

Answer 1

Question 2

Dermatomyositis

Extent of muscle involvement

Answer 2

Question 3

Dermatomyositis

Extent of cutaneous involvement

Answer 3

Question 4

Dermatomyositis

Extra-cutaneous manifestations

Answer 4

Question 5

Dermatomyositis

Clinical subsets, autoAb implicated in each clinical subset

Answer 5

Question 6

Dermatomyositis

Investigations and diagnosis

Answer 6

Question 7

Dermatomyositis

Management

Answer 7

Question 8

Dermatomyositis

Commonly associated malignancies

Answer 8

Rule out NPC until proven otherwise

Question 9

Name features

Answer 9

 Heliotrope rash around eyelids

 Gottron’s papules along downing line

 Cuticle: small vessel dilatation/ telangiectasia

Question 10

Cutaneous lupus erythematosus (CLE)

Differentiating features between acute, subacute and chronic CLE

Answer 10

Question 11

Subacute cutaneous lupus erythematosus

Clinical features

Answer 11

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

Question 12

Name feature
Ddx

Answer 12

Annular SCLE (urticarial-like)

Question 13

Name feature

Answer 13

Annular SCLE (urticarial-like)

Question 14

Name feature

Ddx

Answer 14

Papulosquamous SCLE

Ddx:
 Psoriasis
 Lichen planus

Question 15

Drug-induced SCLE

Common causative drugs

Answer 15

Question 16

Cutaneous lupus erythematosus

Diagnosis

Answer 16

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

Question 17

Cutaneous lupus erythematosus

Management

Answer 17

Question 18

Acute cutaneous lupus erythematosus

Subtypes
Clinical presentation
Ddx

Answer 18

Question 19

Subacute cutaneous lupus erythematosus

Subtypes
Clinical presentation
Ddx

Answer 19

Question 20

Chronic cutaneous lupus erythematosus

Subtypes
Clinical presentation
Ddx

Answer 20

Question 21

Panniculitis

Definition
D/dx

Answer 21

Question 22

Panniculitis

Histopathological classification

Answer 22

Subcutaneous fat lobule/septal wall

Look at vasculature structure: destroyed or not (vasculitis or not)

Question 23

Septal panniculitis

Types with vasculitis and without vasculitis

Answer 23

Question 24

Lobular panniculitis without vasculitis

Subtypes

Answer 24

Question 25

Septal panniculitis without vasculitis/ Erythema nodosum - Pathogenesis - Causes

Answer 25

Question 26

Erythema nodosum Clinical presentation

Answer 26

Question 27

Erythema nodosum Investigation and diagnosis

Answer 27

Question 28

Erythema nodosum Treatment

Answer 28

Question 29

Erythema induratum/ Lobular panniculitis with vasculitis - Pathogenesis - Clinical presentation

Answer 29

Question 30

Erythema induratum Investigation and diagnosis

Answer 30

Question 31

Erythema induratum Treatment

Answer 31

Question 32

Chronic cutaneous lupus erythematosis: Discoid luous erythematosis - Risk factors

Answer 32

Question 33

Name feature

Answer 33

Discoird lupus lesion with dyspigmentation Hypertrophic lesions develop with significant hyperkeratosis

Question 34

Name feature

Answer 34

Discoid lupus erythematosus Scarring alopecia (always check beind ear for scarring alopecia)

Question 35

Name feature

Answer 35

Lupus panniculitis: depressed area due to inflammatory lesion

Question 36

Medium vessel vasculitis Types with cutaneous involvement Causes

Answer 36

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

Question 37

Medium vessel vasculitis/ Polyarteritis nodosa Clinical features

Answer 37

Question 38

Medium vessel vasculitis/ Polyarteritis nodosa Diagnosis Management

Answer 38

Question 39

Name feature

Answer 39

Erythema nodosum

Question 40

Panniculitis History taking questions P/E Ix

Answer 40

Question 41

Name feature

Answer 41

Cutaneous TB

Question 42

Name feature

Answer 42

tuberculosis verrucosa cutis (TBC: direct inoculation of bacilli into skin, e.g. direct contact in swimming pool)

Question 43

First line investigations for chronic recurrent painful nodules

Answer 43

Question 44

Cutaneous manifestations of DM Pathogenesis

Answer 44

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

Question 45

Cutaneous manifestations of DM List all manifestations

Answer 45

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

Question 46

Name feature Treatment

Answer 46

Question 47

Name feature

Answer 47

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

Question 48

Name feature Cause Treatment

Answer 48

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)

Question 49

Name feature Treatment

Answer 49

Question 50

Name feature Causes

Answer 50

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

Question 51

Cutaneous reaction to DM treatment

Answer 51

Question 52

Cutaneous manifestations of neoplasm

Answer 52

1. Acanthosis nigricans 2. Acquired icthyosis = extreme dryness of skin 3. Amyloidosis 4. Clubbing 5. Coagulopathies/ bruising 6. Cryoglobinemia 7. Cushingoid features 8. Dermatomyositis 9. Erythema gyratum repens = annular rash that comes and goes 10. Hypertrichosis lanuginose = increased hair growth, associated with CA pancreas 11. Leser-Trelat = brownish plaque on face 12. Pemphigus = associated with thymoma 13. Necrolytic migratory erythema = also associated with CA pancreas

Question 53

Generalized pruritis of systemic disease Major Ddx Causes

Answer 53

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

Question 54

Answer 54

Livedo reticularis caused by polyarteritis nodosa (medium vessel vasculitis) Tender nodules, 5-10mm in diameter usually smaller than erythema nodosum

Question 55

Dx and histology

Answer 55

Eryhema nodoum: septal panniculitis without vasculitis Resolves into bruises

Question 56

dx?

Answer 56

Varicose veins Venous eczema (dry scaling itchy skin)

Question 57

Answer 57

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

Question 58

Dx?

Answer 58

Diabetic dermopathy Brownish papule and patches No yellowish appearance No blood vessels