Skin Manifestations of Systemic Disease

Question 1

NF-1

Answer 1

6 or more café au lait spots
Axillary and groin freckling
Neurofibromas
Lisch nodules in the iris

Note:
- NF-1 gene mutation on chromosome 17
- Causes abnormal neurofibrimin protein
- AD inheritance

NF-2 is mutation of Merlin gene on Ch 22 and causes Schwannomas

Question 2

Acanthosis nigricans
a) what is it and where is it?
b) causes?

Answer 2

a) Hyperpigmentation and thickening in the neck/groin/axilla

b) Causes include:
- Adénocarcinoma of the GI tract, lung Ca, lymphoma
- Diabetes, Cushing, acromegaly
- Hereditary

Question 3

Erythema nodosum
a) Presentation
b) Causes
c) What is LofGREN syndrome?
d) Management

Answer 3

a) Tender red nodules, usually on shins, sometimes on thighs and forearms

b) Idiopathic 55%
Sarcoid 25%
IBD
Malignancy (esp. Hodgkin Lymphoma)
Infection - strep, TB, chlamydia, fungal, etc.
Drugs - NSAIDs, penicillins, etc.

c) Acute form of sarcoidosis, involving:
- Generally unwell - fever and malaise
- Rheumatism - bilateral ankle arthritis/arthralgia
- Erythema nodosum
- Nodes - bilateral hilar lymphadenopathy

d) - Manage underlying condition
- NSAIDs for pain
- If severe, and ruled out sepsis, give oral prednisolone

Question 4

Lupus vulgaris
a) Cause
b) Appearance

Answer 4

a) Cutaneous TB

b) Firm red papule, ulcerates

Question 5

Pityriasis rotunda
a) Appearance
b) Associated conditions

Answer 5

a) Perfectly circular scaly patches

b) HCC or gastric Ca

Question 6

Necrolytic migratory erythema

Answer 6

Glucagonoma
- will also have diabetes

Question 7

Paraneoplastic pemphigus
- common antibody

Answer 7

Envoplakin

Question 8

Shiny red-brown or yellow patches on the shins of diabetic patient

Answer 8

Necrobiosis lipoidica
- Granulomatous condition
- Difficult to treat, but sometimes steroids work

Question 9

Lupus pernio
a) Cause
b) Clinical features
c) Treatment

Answer 9

a) Sarcoidosis

b) Bluish-red or violaceous nodules and plaques over the nose, cheeks and ears

c) Topical steroids

Question 10

Secondary syphillis

Answer 10

• Maculopapular rash affecting whole body including palms and soles
• Condylomata lata in flexures/mouth, which are confluent plaques

Question 11

Itchy patient without skin rash: causes

Answer 11

• Iron deficiency
• Uraemia
• Liver failure
• Hypo/hyperthyroid
• Malignancy - do Immunoglobulins and protein electrophoresis, and CXR +/- tumour markers

Question 12

Cutaneous vasculitis
a) Usual appearance
b) Causes
c) Investigations to perform

Answer 12

a) Purpuric lesions

b) - 50% idiopathic
- Drug reactions
- Infections (strep, hepatitis)
- Connective tissue disease
- Malignancy

c) - Full drug history (within 3 months of rash onset)
- Infection screen including ASOT, throat swab, MSU, CXR, syphilis, and viral screen
- Autoantibody screen - ANA, ANCA
- Malignancy screen

Question 13

Brownish pigmented rash on both shins
a) Associated condition
b) Nail feature to look for

Answer 13

a) Pretibial myxoedema - associated with Graves’ disease

b) Thyroid acropachy - clubbing

Question 14

Post-angiography, development of AKI, eosinophilia and livedo reticularis

Answer 14

Cholesterol embolism