[The role of exercise testing in the management of systemic sarcoidosis]

Patients suffering from sarcoidosis sometimes report dyspnoea of effort. The restrictive or obstructive ventilatory problems contribute to this disability, but the systemic manifestations of sarcoidosis should be considered as other possible causes of the dyspnoea.

We report a case of systemic sarcoidosis in a 29 year old man from the Ivory Coast. The disorder presented in December 1999 with generalised symptoms and grade II dyspnoea (Sadoul). Investigations confirmed pulmonary, mediastinal, hepatic, lachrymal and salivary involvement. Lung function tests at rest showed a combined restrictive and obstructive ventilatory defect. The initial exercise test showed evidence of severe limitation of aerobic metabolism with impaired oxygen uptake without limitation of ventilation. The absence of cardiac involvement, confirmed by echocardiography and myocardial isotope scanning, suggested that the dyspnoea was, at least in part, secondary to a "peripheral" muscular abnormality. After 3 months treatment with oral corticosteroids, the clinical and physiological parameters improved. Exercise testing confirmed an improvement in maximum work rate and oxygen uptake. The relative stability of the functional measurements and the subsequent development of myalgia prompted a biopsy of the quadriceps that showed granulomata within the muscle tissue, confirming a sarcoid myopathy. A combination of steroids and methotrexate allowed the patient to increase his exercise capacity without any major change in the resting lung function tests.

This case report underlines the role of exercise testing in determining the cause of dyspnoea. In this patient it contributed to the diagnosis of sarcoid myopathy and lead to modification of his treatment.