Correct!
2. Coccidioidomycosis serology
A coccidioidomycosis serology was markedly positive making a presumptive diagnosis of Valley Fever. A bone biopsy is not necessarily wrong but given a positive coccidioidomycosis serology and a compatible clinical situation is probably not necessary. Serum ACE is often elevated in sarcoidosis but it is unclear how this would have helped in this situation. The patient was begun on fluconazole in addition to her hydration and bisphosphonate therapy. Her serum calcium rapidly returned to the normal range (Figure 3).
Figure 3. Calcium levels during admission. The two normal levels are from previous testing done prior to admission.
Clinically the patient's pseudo-obstruction resolved at a calcium level 8.3 mg/dL and she was eventually discharged. After discharge her calcium levels gradually rose again, so she given chronic bisphosphonates (IV) therapy every 3 months and her calcium levels remained controlled.
Reports of hypercalcemia have been described associated with sarcoidosis, tuberculosis and other granulomatous disorders (4-6). Coccidioidomycosis is a an endemic granulomatous fungal infection found in southwestern United States and known to cause hypercalcemia when the infection is disseminated and involves bone (7-9).
The mechanisms for a granulomatous disease to cause hypercalcemia are not well defined. The overproduction of 1, 25-dihydroxy vitamin D, does occur in sarcoidosis and has been generalized to other granulomatous diseases (8). Calcitriol mediated bone resorption and the production of parathyroid related protein (PTHrP) may also play a role. PTHrP is expressed in most granulomatous lesions but does not necessarily cause hypercalcemia. Fierer, et al. (10) hypothesized that the number of fungal lesions that make PTHrP and the amount produced by each lesion likely plays a role in causing hypercalcemia in coccidioidomycosis. Nearly all the reported cases of infection associated hypercalcemia are the result of disseminated infections. Therefore, an important variable causing this form of hypercalcemia is the number of granulomas able to produce measurable serum levels of PTHrP and this was documented in our patient.
It has been recommended that patients with hypercalcemia due to disseminated coccidioidomycosis should be treated with antifungal therapy and hydration (10,11). Patients with very high levels of calcium such as 15.1 mg/dL may benefit from intravenous hydration and bisphosphonates (11). Symptomatic hypercalcemia causing Ogilvie Syndrome needs to be corrected aggressively because the condition can be very serious and the mortality rate as high as 30% (11).
References