Candidiasis

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Candidiasis is an opportunistic fungal infection caused by Candida species, affecting mucosal surfaces, skin, and systemic organs in immunocompromised individuals.

Aetiology

  • Most commonly caused by Candida albicans.
  • Other species: Candida glabrata, Candida tropicalis, Candida parapsilosis.
  • Endogenous infection from normal flora in immunosuppressed individuals.

Pathophysiology

  • Candida overgrowth occurs when host defences are impaired.
  • Biofilm formation enhances resistance to antifungals.
  • Systemic dissemination can lead to invasive candidiasis affecting the bloodstream and organs.

Risk Factors

  • Immunosuppression (HIV, chemotherapy, corticosteroids).
  • Diabetes mellitus (poor glycaemic control).
  • Recent antibiotic use (disrupts normal flora).
  • Prolonged hospitalisation, central venous catheters.
  • Neonates and elderly patients.

Signs and Symptoms

  • Oropharyngeal candidiasis (oral thrush): white plaques on the tongue and buccal mucosa.
  • Oesophageal candidiasis: dysphagia, odynophagia, retrosternal pain.
  • Vulvovaginal candidiasis: pruritus, thick white discharge, erythema.
  • Candidal skin infections: intertrigo, diaper rash.
  • Invasive candidiasis: fever, hypotension, multi-organ involvement.

Investigations

  • Microscopy and culture: KOH preparation shows budding yeasts and pseudohyphae.
  • Blood cultures: positive in disseminated candidiasis.
  • Endoscopy: for oesophageal candidiasis if symptoms persist.

Management

1. Localised Candidiasis:

  • Oropharyngeal candidiasis: topical nystatin or miconazole gel.
  • Vulvovaginal candidiasis: clotrimazole pessary or oral fluconazole.

2. Systemic or Invasive Candidiasis:

  • First-line: IV echinocandins (caspofungin, micafungin) or fluconazole.
  • Remove any central venous catheters if present.

3. Prevention:

  • Optimise glycaemic control in diabetics.
  • Minimise unnecessary antibiotic use.
  • Maintain good oral and skin hygiene.

4. Referral:

  • Infectious diseases: for invasive or recurrent candidiasis.
  • Gynaecology: for persistent vulvovaginal candidiasis.
  • Gastroenterology: for oesophageal involvement requiring endoscopy.
Infectious DiseasemypanotesCandidiasis