Sarcoidosis in the Middle East.

Sarcoidosis, a systemic granulomatous disease of unknown cause, has been described worldwide and in all populations with notable differences in clinical characteristics, organ involvement, disease severity, and prognosis among different ethnic and racial groups. While the exact prevalence of sarcoidosis in the Middle East is unknown, studies from various countries in the region have reported the clinical characteristics of affected patients, along with a few anecdotal reports. A search of the MEDLINE and Google Scholar databases was conducted for relevant English-language articles using the terms "sarcoidosis" and "Middle East" or "sarcoidosis" and "Arabs." Subsequently, the names of individual countries were used as search terms, replacing "Middle East." Overall, the clinical picture of patients with sarcoidosis in the Middle East is similar to that reported elsewhere; for example, the disease was more frequent among females and respiratory complaints were the predominant symptoms. Within the region, most patients from Oman were older and female, with arthralgia, hypercalcemia, and eye involvement being more common. Constitutional symptoms were frequent, especially among patients from Iran. Cough was more common among patients from Kuwait and Iran, while dyspnea was the predominant symptom for Saudi patients. Erythema nodosum was more common in the Turkish population. Clustering was seen in patients with Stage I and II of the disease in all countries except Oman. Apart from those in Iran, the prognosis of most patients from the Middle East was excellent.