Pulmonary sarcoidosis in adults

Sarcoidosis is a chronic, multiorgan granulomatous disorder of unknown aetiology. Pulmonary involvement occurs in up to 90% of patients with sarcoidosis, ranging from asymptomatic mediastinal/hilar lymphadenopathy (often detected incidentally) through to progressive pulmonary fibrosis, which may result in respiratory failure and death.

Symptoms related to pulmonary sarcoidosis include dyspnoea on exertion and cough. Pulmonary sarcoidosis is not associated with many clinical signs; finger clubbing is not a feature. Pulmonary infiltration is usually bilateral with nodular shadowing typically in the mid-zones. More dense infiltration leading to reticulonodular shadowing and fibrosis of the upper lobes is seen in advanced cases. Nodules may be present along the pleural surfaces, but pleural effusion is rare.

The natural course of pulmonary sarcoidosis is variable. In many patients (particularly those with isolated mediastinal/hilar lymph node involvement), spontaneous resolution occurs without treatment.

The role of corticosteroids in pulmonary sarcoidosis is controversial. Patients are often observed for a period before starting therapy, because spontaneous resolution may occur. Oral corticosteroids may be beneficial in some situations (eg asymptomatic pulmonary disease with persistent infiltrates or progressive loss of lung function, or progressive symptomatic pulmonary disease).

Other therapy is primarily targeted to extrapulmonary disease, which is common and may involve the skin (see sarcoidosis in skin), eyes, nervous system, heart or kidneys. Magnetic resonance imaging (MRI) may be required to identify cardiac sarcoidosis. Hypercalcaemia and hypercalciuria may occur. Ophthalmological assessment should also be considered.