142 AJTCCM VOL. 28 NO. 4 2022
EDITORIAL
The diagnosis and management of sarcoidosis continue to be
a challenge, as Morar and Feldman[1] remind us in this issue of
AJTCCM. As noted by them, and in the general South African
specialist experience, sarcoidosis is regularly misdiagnosed as
tuberculosis (TB). A little extra eort in radiology training and
expertise is required, but tends to be a deciency in undergraduate
training throughout the country. Being an orphan disease,
sarcoidosis is also rarely a topic of CME activities among medical
officers and general practitioners, limiting their expertise. And
when it is misdiagnosed, it is dicult to understand why treatment
is oen continued for prolonged periods – oen 9 months or longer
– before the diagnosis is reconsidered. One resulting complication
is that patients are unnecessarily exposed to the side-eects of anti-
tuberculosis therapy. Another is that complications of sarcoidosis
may continue unabated: pulmonary fibrosis, and ocular and
metabolic complications such as hypercalcaemia and its sequelae.
One can understand that the interstitial abnormalities may be
confused with TB, but we should remember that mediastinal and
paratracheal adenopathy are generally not features of TB in the
immunocompetent, and should trigger a reconsideration of the
diagnosis.
e traditional radiographic staging of sarcoidosis has been questioned
for its accuracy and poor interobserver concordance.[2] Itis probably
anachronistic and ought to be relegated to history, as it is incorrect and
has minimal clinical signicance for the following reasons: (i)patients
do not progress through the stages; (ii) computed tomography
scanning is superior and is likely to demonstrate lymphadenopathy and
parenchymal changes that cannot be appreciated on chest radiographs;[2]
(iii) a chest radiograph with normal lung elds does not mean that there
is no parenchymal involvement – non-caseating granulomas have been
found in up to 100% of such patients undergoing lung biopsy;[3] and
(iv)one cannot be certain about the so-called end-stage brosis, because
there may still be active granulomas that are dicult to discern amid
the brosis.[4]
Rather, one should merely note the radiological abnormalities and
take them into consideration in decision-making without assigning a
specic stage.
As regards lung function testing, 21% of patients were noted to
have an obstructive defect. With sarcoidosis being an interstitial
lung disease, one would have expected all to have a restrictive defect.
However, the characteristic peribronchial distribution of granulomas
results in an obstructive defect as the commonest abnormality, and
should also not result in a misdiagnosis of asthma.[5] e fact that
more patients had restrictive defects is a reectionofthe larger
proportion having interstitial changes, and has bearing on the
following observation in the study.
A high proportion of Morar and Feldman’s patients needed
corticosteroids and relapsed on cessation of therapy. is nding
probably reects the spectrum of sarcoidosis seen at referral centres.
Patients with acute and self-limiting forms of the disease are, not
unexpectedly, seldom referred to specialist clinics. ose with recurrent
or persistent symptoms and activity limitation are more likely to be
referred to specialists and require long-term immunosuppression or
corticosteroid-sparing agents. In a total population of sarcoidosis
patients, ~10 - 30% will develop progressive pulmonary disease.[6]
Chronic pulmonary sarcoidosis can be a therapeutic challenge. A
prompt and accurate diagnosis has important clinical implications,
as has delineating the extent of involvement and surveillance for new
organ involvement and the pulmonary course. ese have an inuence
on morbidity and mortality and ensuring optimal patient outcomes.
E M Irusen, PhD
Head, Division of Pulmonology, Department of Medicine, Stellenbosch
University, Cape Town, South Africa
1. Morar R, Feldman C. Sarcoidosis in Johannesburg, South Africa: A retrospective study. Afr
J oracic Crit Care Med 2022;28(4):150-156. https://doi.org/10.7196/AJTCCM.2022.
v28i4.205
2. Silva M,Nunes H,Valeyre D,Sverzellati N. Imaging of sarcoidosis. Clin Rev Allergy
Immunol 2015;49(1):45-53. https://doi.org/10.1007/s12016-015-8478-7.
3. Koontz CH. Lung biopsy in sarcoidosis. Chest 1978;742:120121. https://doi.
org/10.1378/chest.74.2.120
4. Mostard RLM, Verschakelen JA, van Kroonenburgh MJPG, et al. Severity of
pulmonary involvement and (18)F-FDG PET activity in sarcoidosis. Respir Med
2013;107(3):439-447. https://doi.org/10.1016/j.rmed.2012.11.011
5. HarrisonBD,Shaylor JM,Stokes TC,Wilkes AR. Airow limitation in sarcoidosis – a
study of pulmonary function in 107 patients with newly diagnosed disease. Respir
Med 1991;85(1):59-64. https://doi.org/10.1016/s0954-6111(06)80211-8
6. Belperio JA, Shaikh F, Abtin FG, et al. Diagnosis and treatment of pulmonary
sarcoidosis: A review. JAMA 2022;327(9):856-867. https://doi.org/10.1001/
jama.2022.1570
Afr J Thoracic Crit Care Med 2022;28(4):142.
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Sarcoidosis – time for a clinical refresher!
