Woman, 64, With Eye Pain, Swelling, and Tearing

Sarcoidosis. Sarcoidosis is a multisystem inflammatory disease characterized by noncaseating epithelioid granulomas in affected organs.⁶ More than 90% of patients with sarcoidosis present with pulmonary symptoms, including shortness of breath, cough, and pleuritic chest pain.^6-8 Ocular manifestations, such as uveitis, iritis, or conjunctivitis, are less common, developing in 30% to 60% of patients.^2,9,10 In addition, rashes, lesions, or cutaneous skin nodules, including erythema nodosum and lupus pernio, are seen in 25% to 35% of patients.^2,6

In up to two-thirds of patients, sarcoidosis resolves spontaneously²; in others, it may become chronic and progressive.⁴ Patients may have few or no symptoms; some require no treatment, while others may be severely affected by the disease.

Ocular involvement in sarcoidosis generally manifests as uveitis, most commonly in the anterior chamber. Uveitis is a potentially vision-threatening inflammatory disease involving both the uveal tract and adjacent structures.¹¹ In a review of records for 2,619 patients with uveitis, 59.9% had anterior disease, of whom 2.1% were diagnosed with sarcoidosis.¹¹

While the etiology of sarcoidosis continues to be studied,⁷ the prevailing theory is that, in genetically predisposed individuals, sarcoidosis is a cell-mediated immune response to as-yet unknown antigen triggers that leads to granuloma formation.^3,6,7

CD4+ activated T-cells stimulate the immune reaction against an antigen, producing cytokines that activate immune cells (eg, B cells, macrophages, monocytes, and neutrophils).² Immune cells accumulate and aggregate at antigen sites in an exaggerated response, resulting in the formation of granulomas (see Figure 2).^7,12,13

Infectious agents have long been investigated as possible causative agents in sarcoidosis, with Mycobacterium species most frequently identified.⁵ Additional possibilities include Propionibacterium acnes (found predominantly in skin lesions) and herpesviruses, although viruses are not known to cause epitheliod granulomas.¹⁴

Environmental triggers have also been explored. One large study found a possible association between exposure to insecticides, agricultural environments, and microbial bioaerosols and sarcoidosis.¹⁵

The difficulty of pinpointing a single etiology for sarcoidosis—with its varying clinical manifestations, severity, and disease course—suggests that sarcoidosis may be a spectrum of disorders caused by the interaction of genetic, immunologic, infectious, and environmental factors.¹⁴

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