Makindo Medical Notes

Candida is an almost ubiquitous commensal found on the skin, in the oral cavity, and in the genital tract. Invasive disease can be subtle in critically ill or immunocompromised patients, particularly in those on broad-spectrum antibiotics, with central lines, or those ventilated in intensive care units. Vigilance is required, especially if Candida is isolated from a normally sterile site, such as a blood culture. Early use of systemic antifungals should be considered under expert guidance.

About

• Opportunistic Infection: Candida infections are primarily caused by Candida albicans, though other species (e.g., Candida glabrata, Candida krusei) can also lead to similar syndromes.
• At-Risk Populations: Common in immunocompromised patients, particularly those on intensive care units, undergoing chemotherapy, or who are intravenous drug users.
• Endophthalmitis: An important early sign of disseminated candidiasis, particularly in patients with candidaemia.

Aetiology

• Ubiquitous Fungus: Candida species are widespread in the environment and human flora, primarily found in the gastrointestinal tract, skin, and mucous membranes.
• Most Common Fungal Pathogen: Candida species are the leading cause of fungal infections in humans, particularly in hospital settings.

Clinical Presentations

• Localised Mucosal Infections (e.g., Thrush):
  • Commonly affects the oropharyngeal or vaginal mucosa, presenting with white plaques or redness.
  • Risk factors include diabetes, denture use, immunosuppression (e.g., HIV), antibiotic therapy, and xerostomia.
  • Oesophageal candidiasis (especially in AIDS) may cause odynophagia and dysphagia.
• Acute Disseminated Candidiasis:
  • Occurs in immunocompromised patients, especially those with central lines, recent abdominal surgery, or on parenteral nutrition.
  • Presents with fever, malaise, and potentially endophthalmitis (retinal cotton wool spots).
• Chronic Disseminated (Hepatosplenic) Candidiasis:
  • Common in patients with neutropenia; symptoms persist even after neutrophil recovery.
  • May involve spleen, liver, or kidneys, often visible as abscesses on imaging.
• Chronic Mucocutaneous Candidiasis:
  • Associated with immune disorders, often presenting with severe oral thrush, nail infections, and recurrent vaginitis.
  • Can be part of polyglandular autoimmune syndrome type I.
• Invasive Complications:
  • Candida can cause endocarditis, pyelonephritis, meningitis, and osteomyelitis, particularly in immunocompromised patients.

Investigations

• Mucocutaneous Disease: Scrapings or smears from the affected area (skin, nails, oral, or vaginal mucosa) should be examined microscopically for yeast, hyphae, or pseudohyphae.
• Urine Cultures: Candida growth in urine can indicate candiduria, especially in catheterized patients.
• Blood Cultures: Positive cultures should prompt further evaluation, as candidaemia indicates invasive infection.
• Hepatosplenic Disease: May present with elevated alkaline phosphatase levels.
• Imaging:
  • CXR: May show bronchopneumonia suggestive of Candida.
  • OGD (Oesophagogastroduodenoscopy): Useful for diagnosing oesophageal candidiasis.
  • Abdominal Imaging (CT/USS): Can identify solid organ abscesses.
  • Echocardiography: Essential for detecting fungal endocarditis.

Management

• Diabetes Management: Optimal blood glucose control is essential.
• Catheter Removal: Any indwelling catheter or device suspected as the infection source should be removed promptly.
• Mucocutaneous Disease:
  • Topical clotrimazole cream (1%) or nystatin for local application, typically for 14 days.
  • For vaginal candidiasis, use vaginal pessaries or fluconazole tablets.
  • Oral fluconazole for cases unresponsive to topical treatments or in immunosuppressed individuals.
  • Other agents include itraconazole and terbinafine.
• Systemic Candidiasis:
  • Administer IV antifungals such as amphotericin B or lipid formulations for severe cases.
  • Alternative agents include fluconazole or echinocandins (e.g., caspofungin, micafungin).
  • Treatment duration typically extends to 14 days post-culture clearance.
  • Consult microbiology or infectious disease specialists for optimal treatment strategies.