Sarcoidosis

Question 1

What is sarcoidosis?

Answer 1

Multisystem disease of unknown aetiology characterised by the presence of non-caseating granulomas (unlike TB) in tissues and organs.

Question 2

What is a granuloma?

Answer 2

An aggregation of activated macrophages.

Question 3

What organs does sarcoidosis affect?

Answer 3

1. Lymph nodes
2. Lungs
3. Skin
4. Eyes
5. Lacrimal and salivary gland
6. Nervous system

Question 4

How does sarcoidosis affect the lymph nodes?

Answer 4

1. Virtually all cases of sarcoidosis involves lymph nodes.
2. Hilar and mediastinal lymphadenopathy
3. Picked up on CXR

Question 5

How does sarcoidosis affect the lungs?

Answer 5

1. Lungs frequently involved
2. Lung fibrosis from healing of granulomas
3. Cor pulmonale and respiratory failure if severe

Question 6

How does sarcoidosis affect the skin?

Answer 6

1. Lupus pernio - maculopapular rash on face and trunk

2. Erythema nodosum associated with sarcoidosis

Question 7

How does sarcoidosis affect the eyes?

Answer 7

Uveitis - inflammation of uveal tract:

1. Anterior - red, painful eye with photophobia, self-limiting.
2. Posterior - floaters, blurred vision, chronic form of disease.

Question 8

How does sarcoidosis affect the lacrimal and salivary glands?

Answer 8

Dry eyes and mouth

Question 9

How does sarcoidosis affect the nervous system?

Answer 9

1. CN VII palsy common

2. Hypothalamic involvement common - causing diabetes insipidus due to destruction of ADH producing neurons.

Question 10

What is this describing and what is the prognosis?

Associated with manifestations that include bilateral hilar lymphadenopathy, anterior uveitis and CN VII palsy.

Answer 10

1. Acute sarcoidosis (most patients with sarcoidosis)

2. Good prognosis, spontaneous resolution within 1-2 years of diagnosis, no chronic consequences.

Question 11

What is this describing and what is the prognosis?

Associated with lupus pernio, pulmonary fibrosis and posterior uveitis.

Answer 11

1. Chronic sarcoidosis (5% of patients with sarcoidosis)

2. Tends to persist and lead to permanent organ damage.

Question 12

What are the findings in blood tests of sarcoidosis?

Answer 12

1. ESR raised
2. Hypercalcaemia present in 10% (granulomas convert vit D to active form)
3. Raised serum ACE (granulomas produce)

Question 13

How is sarcoidosis effectively diagnosed?

Answer 13

Biopsy in less clear-cut cases, otherwise clinical and simple tests ruling out other conditions.