Sarcoidosis

Question 1

What is sarcoidosis?

Answer 1

A multisystem inflammatory disorder of unknown aetiology characterised by non-caseating granulomas, most common in young adults and people of African descent.

Question 2

What symptoms characterise acute sarcoidosis presentations?

Answer 2

Erythema nodosum, bilateral hilar lymphadenopathy, swinging fever and polyarthralgia.

Question 3

What symptoms characterise insidious (chronic) sarcoidosis presentations?

Answer 3

Dyspnoea, non-productive cough, malaise and weight loss.

Question 4

What are the key ocular manifestations of sarcoidosis?

Answer 4

Uveitis is the most common ocular feature.

Question 5

What is lupus pernio and why is it clinically important?

Answer 5

Chronic violaceous indurated plaques on the nose or face, associated with upper respiratory tract involvement and indicating chronic disease with poor prognosis requiring systemic therapy.

Question 6

Why does sarcoidosis cause hypercalcaemia?

Answer 6

Macrophages in granulomas increase conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol).

Question 7

What is Löfgren’s syndrome?

Answer 7

An acute form of sarcoidosis characterised by bilateral hilar lymphadenopathy, erythema nodosum, fever and polyarthralgia, associated with an excellent prognosis.

Question 8

What is Heerfordt’s syndrome?

Answer 8

Uveoparotid fever: parotid gland enlargement, fever and uveitis due to sarcoidosis.

Question 9

How reliable is ACE as a diagnostic test in sarcoidosis?

Answer 9

Serum ACE has a sensitivity of 60% and specificity of 70%, so it is not diagnostic but can help monitor disease activity.

Question 10

What blood test abnormalities may be seen in sarcoidosis?

Answer 10

Hypercalcaemia (in ~10% of patients) and raised ESR.

Question 11

How is chest X-ray used to stage sarcoidosis?

Answer 11

Stage 0: normal; Stage 1: bilateral hilar lymphadenopathy; Stage 2: BHL plus interstitial infiltrates; Stage 3: diffuse interstitial infiltrates only; Stage 4: diffuse fibrosis.

Question 12

What spirometry pattern is associated with sarcoidosis?

Answer 12

A restrictive defect.

Question 13

What is the diagnostic hallmark on tissue biopsy in sarcoidosis?

Answer 13

Non-caseating granulomas.

Question 14

Why is the Kveim test no longer used in sarcoidosis?

Answer 14

It is discontinued due to concerns over cross-infection.

Question 15

When are steroids indicated in sarcoidosis?

Answer 15

In symptomatic stage 2 or 3 chest X-ray disease, hypercalcaemia, or eye, cardiac or neurological involvement. Asymptomatic stable stage 2 or 3 disease with only mildly abnormal lung function does not require treatment.

Question 16

What proportion of sarcoidosis cases remit spontaneously?

Answer 16

Approximately two-thirds of cases remit without treatment.

Question 17

What clinical features are associated with poor prognosis in sarcoidosis?

Answer 17

Insidious onset with symptoms lasting more than six months, absence of erythema nodosum, extrapulmonary disease such as lupus pernio or splenomegaly, chest X-ray stage III or IV disease, and Black African or African-Caribbean ethnicity.