Hypercalcemic crisis due to primary hyperparathyroidism in systemic lupus erythematosus (SLE).

Severe hypercalcemia is often caused by primary hyperparathyroidism (PHP), which is not commonly seen in patients with systemic lupus erythematosus (SLE). In this case report an adolescent girl with a history of SLE develops mild hypercalcemia secondary to unrecognized PHP that leads to a hypercalcemic crisis with a prolonged recovery. Therefore, early diagnostic evaluation of persistent hypercalcemia in patients with SLE is important for detection and appropriate treatment of PHP to avoid a hypercalcemic crisis and associated prolonged morbidity.