A Case of Hypercalcemia and Scabies

Abstract

Hypercalcemia has been associated with most granulomatous diseases. Sometimes it is a common manifestation, as in sarcoidosis, tuberculosis, or lymphomas.1Shepard M.M. Smith J.W. Hypercalcemia.Am Med Sci. 2007; 334: 381-385Crossref PubMed Scopus (31) Google Scholar For several other granulomatous diseases, it is a rare occurrence. It was described in diseases like Wegener granulomatosis, Crohn disease, histiocytosis X, silicone-induced granulomatous diseases, and berylliosis.2Bosch X. Hypercalcemia due to endogenous overproduction of 1,25-dihydroxyvitamin D in Crohn's disease.Gastroenterology. 1998; 114: 1061-1065Abstract Full Text Full Text PDF PubMed Scopus (40) Google Scholar There are reports in infectious diseases: cryptococcosis, coccidioidomycosis, Mycobacterium leprae, and cat-scratch disease, to name a few3Ali M.Y. Gopal K.V. Llerena L.A. et al.Hypercalcemia associated with infection by Cryptococcus neoformans and Coccidioides immitis.Am J Med Sci. 1999; 318: 419-423Crossref PubMed Scopus (38) Google Scholar, 4Bosch X. Hypercalcemia due to endogenous overproduction of active vitamin D in identical twins with cat-scratch disease.JAMA. 1998; 279: 532-534Crossref PubMed Scopus (41) Google Scholar but not with scabies. A 40-year-old man presented in August 2003 with a calcium level of 4.04 mmol/L, and his serum creatinine level was 486 μmol/L. He was treated with intravenous fluids, furosemide, and pamidronate. His serum calcium and kidney function quickly recovered. The history did not reveal a possible rare cause like milk-alkali syndrome, vitamin D or A intoxication, lithium intake, or immobilization. 25-OH-D levels were normal. 1.25(OH)2 vitamin D assay is not available in our center. We immediately searched for the 2 most frequent etiologies, which are primary hyperparathyroidism and cancer. A low parathyroid hormone excluded the first one, so we focused our investigation on neoplastic diseases. Search for myeloma was negative. The thoracic and abdominal computed tomography scan revealed small axillary and inguinal lymph nodes. Positron emission tomography scan revealed mild uptake of axillary and inguinal lymph nodes (Figure). A right axillary lymph node biopsy showed nonspecific inflammation. Even though the lymph node sample did not reveal a classic granuloma, sarcoidosis and other granulomatous diseases now needed consideration. A self-remitting sarcoidosis is very unlikely, considering his normal chest radiograph, rapid spontaneous remission without corticosteroids, and low angiotensin-converting enzyme serum level. Skin examination revealed excoriated erythematous papules of the limbs, trunk, groins, and genitals. There were interdigital burrows on the hands. A diagnosis of scabies was made by identification of mites and eggs on skin scrapings. Treatment with permethrin was started. Granulomas have been described in association with scabies. They often arise weeks to months after the beginning of the infection.5Wilsmann-Theis D. Wenzel J. Gerdsen R. Uerlich M. Bieber T. Granuloma annulare induced by scabies.Acta Derm Venereol. 2003; 4: 318Crossref Scopus (5) Google Scholar There also are some reports of scabetic nodules with a histological resemblance to malignant lymphoma.6Desmons F. Bombart M. Desurmont B. Scabietic granuloma in infants and young children [French].Dermatologica. 1977; 155: 169-171PubMed Google Scholar The mechanism responsible for hypercalcemia in granulomatous diseases is increased conversion of calcitriol (1.25[OH]2D) from calcidiol. Activated macrophages have a higher activity of their 1-α-hydroxylase that transforms 25(OH)D into active Vitamin D. Exposure to ultraviolet rays is a known risk factor for hypercalcemia in granulomatous diseases.1Shepard M.M. Smith J.W. Hypercalcemia.Am Med Sci. 2007; 334: 381-385Crossref PubMed Scopus (31) Google Scholar Our patient's skin problem had begun 4 months prior. He had been diagnosed in another center with pytriasis rosea and recently was being treated with phototherapy. This ultraviolet source probably triggered the hypercalcemia and the ensuing acute renal failure. Over the years, 4 more positron emission tomography scans were done and became completely normal (Figure). His serum calcium levels have remained normal throughout the 6 years of follow-up. In conclusion, scabies should be added to the list of infectious diseases that can induce hypercalcemia. We would like to thank Dr. Bruno Maynard, dermatologist, Dr. Jean Verreault, Nuclear Medicine Specialist, and Dr. Khun Visith Keu, resident in Nuclear Medicine.