Sarcoidosis. Close-up of a raised lump (granuloma) on the skin above a patient's eye, due to the condition sarcoidosis. Sarcoidosis is a chronic disorder that causes the body's lymph nodes to become enlarged. Small nodules (granulomas) also develop in the lungs, liver and spleen and on the skin, as seen here. The granulomas are composed of several types of white blood cell, as well as giant cells. The causes of sarcoidosis may include an allergic response, infection, or exposure to certain chemicals. Most patients recover completely without treatment, but corticosteroid drugs can be taken in particularly severe or persistent cases.