Erythema nodusum

Question 1

Define erythema nodusum

Answer 1

Panniculitis (inflammation of subcutaneous fat tissue) presenting as red or violet subcutaneous nodules

Question 2

Aetiology of erythema nodusum

2

Answer 2

Delayed hypersensitivity reaction to antigens associated w/ various infectious agents, drugs & diseases
25% cases have no identifiable cause

Question 3

Causes of erythema nodusum

5 groups

Answer 3

Infection
Systemic disease
Malignancy
Drugs
Pregnancy

Question 4

Causes of erythema nodusum - infection

3

Answer 4

Bacterial - e.g. streptococcus
Viral - e.g. EBV
Fungal - e.g. histoplasmosis

Question 5

Causes of erythema nodusum - systemic disease

3

Answer 5

Sarcoidosis
IBD
Behcet’s disease

Question 6

Causes of erythema nodusum - malignancy

2

Answer 6

Leukaemia

Hodgkin’s lymphoma

Question 7

Causes of erythema nodusum - drugs

3

Answer 7

Sulphonamides
Penicillin
Oral contraceptive pills

Question 8

Epidemiology of erythema nodusum

age, gender

Answer 8

Usually affects young adults

3x more common in FEMALES

Question 9

Presenting symptoms of erythema nodusum

8

Answer 9

Tender red/violet nodules bilaterally on both shins
Occasionally on thighs or forearms
Fatigue
Fever
Anorexia
Weight loss
Arthralgia
Symptoms of underlying CAUSE

Question 10

Signs of erythema nodusum on physical examination

6

Answer 10

Crops of red/violet dome-shaped nodules usually present on both shins
Occasionally appear on thighs & forearms
Nodules tender to palpation
Low grade pyrexia
Joints may be tender & painful on movement
Signs of underlying CAUSE

Question 11

Investigations for erythema nodusum

8

Answer 11

Determine underlying CAUSE

Bloods
Anti-streptolysin-O titres (streptococcal infection check)
FBC/CRP/ESR (for signs of infection)
U&Es
Serum ACE (raised in sarcoidosis)

Throat swab & cultures
Mantoux/head skin testing (for TB)
CXR (check bilateral hilar lymphadenopathy or other evidence of TB, sarcoidosis or fungal infections)