Hypercalcemia in patients with disseminated coccidioidomycosis

Granulomatous disorders may be associated with hypercalcemia. In sarcoidosis, the pathogenesis of hypercalcemia has been clarified, whereas in other granulomatous disorders, such as coccidioidomycosis, the mechanism is unclear. We present 13 patients with coccidioidomycosis and hypercalcemia to illustrate the clinical course and the mechanism of hypercalcemia.

We retrospectively reviewed all patients admitted to Kern Medical Center, a 270-bed public hospital, from 1990 through 1997 with coccidioidomycosis and a serum calcium level of greater than 10.5 mg/dL on at least 3 occasions. In addition, no other causes for hypercalcemia were identified.

The mean highest serum calcium level was 12.7 +/- 1.8 mg/dL. All patients had disseminated disease. Six patients were nonambulatory and 4 had bone involvement. Of the 9 patients in whom parathyroid hormone was measured, it was normal in 6 and suppressed in 3. Of the 9 patients in whom 25-hydroxyvitamin D was measured, it was normal in 6, suppressed in 2, and elevated in 1. Of the 7 patients in whom 1,25-dihydroxyvitamin D was measured, it was normal in 3 and suppressed in 4. Urinary calcium was elevated in 2 patients, both of whom were ambulatory. Nonambulatory patients had significantly higher serum calcium levels (14.3 +/- 1.0 mg/dL) than ambulatory patients (11.3 +/- 0.46 mg/dL) (P<0.001).

The mechanism of hypercalcemia in coccidioidomycosis is unrelated to increased production of 1,25-dihydroxyvitamin D. Nonambulatory status is associated with higher mean serum calcium.