Derm - Erythema Nodosum

Question 1

What is erythema nodosum?

Answer 1

Condition where red lumps appear on shins

Question 2

What is erythema nodosum caused by?

Answer 2

Inflammation of the subcutaneous fat on the shins

Caused by a hypersensitivity reaction

Question 3

What is inflammation of fat called?

Answer 3

Panniculitis

Question 4

What conditions can cause erythema nodosum?

Answer 4

Caused by hypersensitivity reaction often caused by :
- Streptococcal throat infections
- Gastroenteritis
- Mycoplasma pneumoniae
- Tuberculosis
- Pregnancy
- Oral contraceptive pill and NSAIDs

Question 5

What chronic diseases is erythema nodosum associated with?

Answer 5

IBD
Sarcoidosis
Lymphoma
Leukaemia

Question 6

How does erythema nodosum present?

Answer 6

Red, inflamed, subcutaneous nodules across both shins

Nodules are raised, can be painful and tender

Over time nodules settle and appear as bruises

Question 7

How is erythema nodosum diagnosed?

Answer 7

Clinical presentation

Question 8

What investigations are used for identifying the underlying cause in erythema nodosum?

Answer 8

CRP and ESR
Throat swab - strep infection
CXR- Mycoplasma, tuberculosis, sarcoidosis and lymphoma
Stool microscopy and culture - campylobacter and salmonella
Faecal calprotectin - IBD

Question 9

How is erythema nodosum managed?

Answer 9

Investigating for underlying cause and treating it

Conservative management with rest and analgesia

Steroids can be used to help settle inflammation

Question 10

How long do most cases of erythema nodosum take to resolve?

Answer 10

6 weeks