So the manifestation
of extrapulmonary sarcoid
are complicated because there merely are different
types. The common forms are eye involvement
with an acute uveitis and scleritis. Parotid
and salivary gland enlargement which can lead
to palpable masses, now normally, this is symmetrical
and the patient may get dry mouth in sicca syndrome.
A neurological involvement is not uncommon
and is quite a serious problem because it
may lead to peripheral neuropathy, cranial
nerve palsies, and deposits in the central
nervous system into chronic neurological defects.
Skin involvement is also common. Now, the
acute presentation as we discussed is with painful
lumps on the shin, erythema nodosum. But the
chronic form is quite different. It's a non-tender
blue nodules especially in scars doesn’t
have to be in the lower legs, it could
be anywhere in the body, and that forms a
powerful infiltration in patients with chronic
sarcoidosis. And important diseases are cardiac
disease because that can lead to conduction
defects and it actually present with disrythmias including
sudden death. And in some patients, also can
lead to restrictive cardiomyopathy. So that’s
a very important form of sarcoid that’s
not uncommon but not the commonest presentation.
And nasal destruction is a very rare form
of sarcoid which leads to very unpleasant
destruction of the nose. As well as those
conditions, you can also have sarcoid affecting
the reticuloendothelial system causing a hepatosplenomegaly
and abnormal liver function test but not normally
causing any functional liver impairment that
is clinically detectable. The spleen is frequently
enlarged due to infiltration with sarcoidosis,
and you may get nodal disease in the extrathoracic
lymph nodes that could be in the neck, in
the abdomen, in the groin.
Joints are often involved to a certain extent
with arthralgia, and you can get bone system
in the infiltration of sarcoidosis … around the
joints. And endocrine problems are a potential
issue. They’re relatively rare but they’re
important because they require treatment.
For example, a hypercalcaemia can occur in
5% of patients with chronic sarcoidosis and
will need treatment. Occasionally, you get
infiltration in the pituitary area with
sarcoid granulomas leading to hypopituitarism
and diabetes insipidus. Very rare but
very important manifestation of the disease. So,
how do we investigate patient with sarcoidosis?
It is similar to other interstitial lung disease
with the chest X-ray, lung function, and a
CT scan. Unfortunately, these normally add upto the
picture which is very suggestive with sarcoidosis,
for example, if the chest X-ray will show
bilateral, hilar, and mediastinal lymph node
involvement and upper lobe infiltrations as
we have already discussed.
The lung function will show restrictive obstructive
picture with a fall in transfer factor, a
little seen as your hypersensitivity pneumonitis
where you get a mixed restrictive obstructive
picture rather than the pure restrictive picture.
And the CT scan will show bilateral, hilar,
and mediastinal lymph node enlargements, diffused
parenchymal nodules with the upper lobe predominance
we’ve already discussed, and actually, very
characteristically you often see little nodules
forming on the edge of the pleura or on the
oblique and horizontal fissures.
These appearances would very strongly suggest
the diagnosis of sarcoidosis. A bronchoscopy
may show a lymphositosis in the lavage, and
blood tests are important because you need
to exclude the presence of the endocrine abnormalities
where we discussed hypercalcaemia, for example,
to look for liver involvement by doing little
function tests. And also, the serum angiotensin
converting enzyme (ACE) level is often raised
in patients with sarcoidosis. Now, it's actually
not particularly a good test because it is often
raised in conditions where there is no sarcoidosis.
However, in a patient with sarcoid and a raised
serum ACE level, it can be useful to monitoring
disease progression. For example, as the disease
gets better, then the serum ACE level would
fall. But if the disease is not improving,
then the serum ACE level will remain high.
Now, the test for involvement with other organs
is dictated by the clinical presentation of
the patient. So if you suspect there might
be cardiac disease, you need to do an ECG,
an echocardiogram. If you suspect there might
be a mediastinal involvement, you have to
do abnormal ultrasound and CT scans and look
for enlarged liver, enlarged spleen, and enlarged
abdominal nodes. And then neurological involvement
requires CT scans, MRI of the brain, etc etc.
So the extrapulmonary sarcoidosis
a very large range of different tests depending
on what the presentation of the patient might be.