Referrals to Rheumatology
Any organ can be affected in this condition, and when multiple organs are affected all at once and no one else can figure it out, a rheumatologist is who gets the call.
“The most bizarre case [of sarcoidosis] I ever saw was in the prostate,” Dr. Yee said.
Dr. Yee and his colleagues are currently conducting a study to better understand rheumatology referral queries. “By and large, these patients are referred to us for medication management. But the question we’re being asked is, ‘What medications will actually work for these patients?’—not what drug to start. We are being asked to adjust therapy, not initiate it. This suggests that [the patients with] sarcoidosis we see are more complicated and more difficult to manage,” he said.
Highlights
Every sarcoidosis manifestation has a broad differential. Example: A multi-system illness should prompt consideration of Sjögren’s disease, tuberculosis, syphilis and lymphoma, among others.
“The bottom line is that there are many different conditions you need to think about. [Studying up on] sarcoidosis is a great way to prepare for the internal medicine boards because you end up learning everything over and over again,” Dr. Yee said.
Interestingly, Dr. Yee noted that—in his opinion—perhaps the most important rheumatic manifestation of sarcoidosis has nothing to do with direct inflammation itself, but rather is a consequence of inflammation: granulomas. Granulomas can convert 25-hydroxy-vitamin-D3 (i.e., the vitamin D level measured on routine bloodwork) into 1,25-dihydroxy-vitamin-D3 in a parathyroid hormone (PTH) independent manner. Thus, 25-hydroxy-vitamin-D3 levels may be low, but 1,25-dihydroxy-vitamin-D3 levels may actually be high in patients. This is a problem because 1,25-dihydroxyvitamin-D3 is the active hormone and too much of it can cause such issues as hypercalcemia, hypercalciuria, nephrolithiasis and osteoporosis.2
“I check 1,25-dihydroxy-vitamin-D3 levels in all [patients with] sarcoidosis because you can’t otherwise tell if they’re [vitamin D] deficient or not, and you may be doing harm if trying to replete someone inappropriately,” he said.
Post-Diagnosis Screening
In 2020, the American Thoracic Society published a clinical practice guideline for the diagnosis and detection of sarcoidosis.3 This document included screening recommendations for patients newly diagnosed with sarcoidosis regardless of clinical manifestations of disease:
- Complete blood count;
- Comprehensive metabolic panel;
- 25-hydroxy-vitamin-D3, 1-25-dihydroxy-vitamin-D3 and calcium levels;
- Electrocardiogram; and
- Ophthalmologic examination.
“Of note, these [recommendations] don’t mention chest X-ray or pulmonary function tests because they take the [pulmonolgist’s] point of view, and pulmonologists automatically order these for their patients. So remember to include these [tests] too, [because] pulmonary sarcoidosis can be asymptomatic,” Dr. Yee said.
