Syndrome of inappropriate secretion of antidiuretic hormone in elderly patients with rheumatoid arthritis associated with infections: report of two cases

SIADH with Severe Hyponatremia in an Elderly Man with Herpes Zoster Infection: A Causal or Casual Association?

Syndrome of inappropriate antidiuretic hormone (SIADH) secretion is the most common cause of hypotonic hyponatremia in hospitalized patients. An elderly man with severe symptomatic hyponatremia (109 mEq/L) was diagnosed with SIADH that was likely secondary to large cutaneous herpes zoster (HZ) infection. Hypertonic saline and tolvaptan improved the patient's sodium levels and clinical condition. A one month after discharge, tolvaptan was withdrawn, due to inadequate prescription criteria, after which hyponatremia relapsed several times and was properly treated; eventually fever and sopor occurred and the patient died. SIADH secondary to HZ may induce life-threatening and long-lasting hyponatremia, which requires a prompt diagnosis and treatment.

Looking back to move forward: a twenty-year audit of herpes zoster in Asia-Pacific

Background

Herpes zoster (HZ) is a prevalent viral disease that inflicts substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable patients. Although widely recommended, vaccination against HZ is not routine; barriers in Asia-Pacific include long-standing neglect of adult immunisation and sparse local data. To address knowledge gaps, raise awareness, and disseminate best practice, we reviewed recent data and guidelines on HZ from the Asia-Pacific region.

Methods

We searched PubMed, Scopus, and World Health Organization databases for articles about HZ published from 1994 to 2014 by authors from Australia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, New Zealand, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. We selected articles about epidemiology, burden, complications, comorbidities, management, prevention, and recommendations/guidelines. Internet searches retrieved additional HZ immunisation guidelines.

Results

From 4007 retrieved articles, we screened-out 1501 duplicates and excluded 1264 extraneous articles, leaving 1242 unique articles. We found guidelines on adult immunisation from Australia, India, Indonesia, Malaysia, New Zealand, the Philippines, South Korea, and Thailand.

HZ epidemiology in Asia-Pacific is similar to elsewhere; incidence rises with age and peaks at around 70 years – lifetime risk is approximately one-third. Average incidence of 3–10/1000 person-years is rising at around 5% per year. The principal risk factors are immunosenescence and immunosuppression. HZ almost always causes pain, and post-herpetic neuralgia is its most common complication. Half or more of hospitalised HZ patients have post-herpetic neuralgia, secondary infections, or inflammatory sequelae that are occasionally fatal. These disease burdens severely diminish patients’ quality of life and incur heavy healthcare utilisation.

Conclusions

Several countries have abundant data on HZ, but others, especially in South-East Asia, very few. However, Asia-Pacific countries generally lack data on HZ vaccine safety, efficacy and cost-effectiveness. Physicians treating HZ and its complications in Asia-Pacific face familiar challenges but, with a vast aged population, Asia bears a unique and growing burden of disease. Given the strong rationale for prevention, most adult immunisation guidelines include HZ vaccine, yet it remains underused. We urge all stakeholders to give higher priority to adult immunisation in general and HZ in particular.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2198-y) contains supplementary material, which is available to authorized users.

Staphylococcus simulans osteitis in a diabetic patient

Staphylococcus simulans was identified as the aetiological agent of osteitis in a diabetic woman. Its identifying characteristics and antibiogram were confirmed. Diabetic foot frequently becomes infected and the spread of infection to bone is a major causal factor behind lower-limb amputation. Early diagnosis and appropriate treatment are essential in such cases.

Syndrome of inappropriate secretion of antidiuretic hormone associated with localized herpes zoster ophthalmicus

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with localized herpes zoster is rarely reported and may be under-appreciated. We describe two diabetic men with herpes zoster ophthalmicus (HZO) who developed hyponatremia (114 and 116 mmol/L) during acute illness. Both were euvolemic and had elevated urine osmolality (435 and 368 mmol/kg.H(2)O) and sodium (Na(+)) concentration (61 and 63 mmol/L) along with normal cardiac, renal, liver, and endocrine function consistent with the diagnosis of SIADH. Thorough investigation for other causes of SIADH, including detailed physical examination, laboratory studies, and computed tomography of the brain, chest, and abdomen, were negative. Despite antiviral therapy (acyclovir) for herpes zoster, ophthalmoplegia, keratitis, and post-herpetic neuralgia (PHN) developed. Even with fluid restriction and high salt diet, SIADH lasted for 3 to 4 months and resolved concomitantly with resolution of PHN, suggesting an association between SIADH and HZO. These two cases raise the potential for herpes zoster infection, especially HZO, to involve the regulatory pathway of ADH secretion, contributing to SIADH. The presence of PHN, which reflects greater neural damage may, at least in part, explain the prolonged ADH secretion and hyponatremia.

Syndrome of inappropriate secretion of antidiuretic hormone and thrombocytopenia caused by cytomegalovirus infection in a young immunocompetent woman

We report the first case of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with cytomegalovirus (CMV) infection. A 32-year-old woman was admitted to our hospital because of pandysautonomic signs and symptoms. Thrombocytopenia and hyponatremia were present. Serum anti-CMV IgM and IgG antibodies were positive. Despite hyponatremia, urinary osmolality exceeded plasma osmolality and plasma vasopressin levels related to plasma osmolality were high. Restriction of water intake and administration of dimethylchlorotetracycline improved hyponatremia, suggesting this patient had SIADH. In this patient, SIADH may have been caused by acute pandysautonomia that developed following CMV infection.

Vertebral osteomyelitis and prosthetic joint infection due to Staphylococcus simulans

Staphylococcus simulans, a coagulase-negative staphylococcus, is a common animal pathogen that is rarely encountered in human infections. We describe a 70-year-old man who developed multifocal vertebral osteomyelitis and late prosthetic joint infection caused by this pathogen. The patient was a farmer who had daily contact with cows and drank unpasteurized milk, although the portal of the pathogen's entry remains speculative. Culture of the vertebral disk biopsy specimen and cultures during resection arthroplasty yielded S. simulans. A review of the literature suggests that S. simulans may be more virulent than other species of coagulase-negative staphylococci. Accurate identification of S. simulans isolates would facilitate studies to further define its pathogenic role in human infections.