Hypercalcemia in histoplasmosis aggravated with antifungal treatment.

INTRODUCTION Hypercalcemia is a known, but rare complication of histoplasmosis, a granulomatous disease. We present a case of chronic disseminated histoplasmosis, complicated by hypercalcemia, transiently worsening after initiation of antifungal treatment. CASE PRESENTATION A 61-year-old gentleman presented with shortness of breath, cough, weight loss, but no fever or hemoptysis. His physical exam was unremarkable except for decreased air entry on both lung fields, and axillary and inguinal lymphadenopathies. Computed tomography of the chest showed bilateral cavitary lung lesions, biopsy of which showed non caseating granulomas, and tissue culture showing Histoplasma capsulatum. Itraconazole was started. One month later, patient presented with transient acute renal failure and worsening hypercalcemia. His workup showed a non-PTH mediated hypercalcemia, with a normal PTH-rP, and low calcifediol, but high normal calcitriol level. Hypercalcemia secondary to histoplasmosis was reported in six cases, none of which worsened after antifungal treatment. Several mechanisms have been elucidated. CONCLUSION We recommend monitoring of serum calcium after initiation of antifungal treatment, especially in patients with underlying hypercalcemia. More studies are needed to understand the pathophysiology.