Systemic candidiasis is an invasive fungal infection caused by the yeast, Candida, resulting in its dissemination in the blood (candidemia) and/or an involvement of other organs (disseminated candidiasis).
Depending on the site of infection by Candida species (mostly Candida albicans), systemic candidiasis can be broadly classified into 2 entities: candidemia, a bloodstream candidial infection, or disseminated candidiasis, characterized by the infection of one or more organs.
Candidemia is mostly nosocomial in origin and manifests primarily as fever that is unresponsive to antibiotics  . Risk factors lowering the immune defense of the individual are frequently present, such as prolonged intravenous catheterization, prosthetic valves, drug abuse, etc . Some patients may also show associated deep-seated infections (disseminated candidiasis) or occasionally features of septic shock.
Disseminated candidiasis may present with fever originating from an unknown source and frequently involves one or more of the following organs: the eyes, central nervous system (CNS), kidneys, heart, musculoskeletal system, etc.
Candida endophthalmitis may arise either from an external source via iatrogenic/ accidental injury or as a consequence of candidemia. Patients may be asymptomatic or may present with pain or visual symptoms such as photophobia, floaters, or scotomas. Fundoscopy may reveal one or many off-white pinhead lesions in the vitreous, extending onto the retina.
The CNS manifestations of disseminated candidiasis vary widely, with meningitis, parenchymal infections, abscesses, mycotic aneurysms, and vasculitis being reported in patients. The usual presenting features include fever, confusion, coma, nuchal rigidity and different sensory/motor symptoms.
Candidial musculoskeletal infections may involve the joints, muscles or bones, with the vertebral column and knees amongst the common sites affected. The sternum, ribs and lower limbs may also be frequently involved.
A positive fungal culture forms the mainstay of diagnosis for systemic candidiasis. However, cultures from non-sterile sites such as the mouth, vagina, stool, sputum or skin are not beneficial in establishing a diagnosis. They may, however, serve as an indication to begin empirical antifungal therapy in clinically susceptible patients.
A positive blood culture helps in the diagnosis but is only seen in 50-60 % of patients with systemic candidiasis   . Cultures from other sterile sites such as the pericardium or the cerebrospinal fluid are diagnostic of invasive disease and should be followed by a prompt initiation of appropriate therapy.
A nonculture assay measuring the serum β-glucan, a component of the fungal cell wall, shows a high specificity for systemic candidiasis . A negative assay reduces the chances of the patient suffering from an invasive disease.
An ophthalmological examination is to be conducted in patients showing manifestations of candidial endophthalmitis as well as in all patients suffering from candidemia. Urinalysis and a subsequent kidney biopsy may help in establishing the diagnosis of renal candidiasis.