Thrush

1. Introduction

  • Definition: Thrush, or candidiasis, is a fungal infection caused by Candida species, commonly Candida albicans. It can affect the mouth (oral thrush), genital area (vaginal thrush), or other parts of the body.
  • Epidemiology: Thrush is common in individuals with weakened immunity, diabetes, or those on antibiotics or corticosteroids. Vaginal thrush affects about 75% of women at least once during their lifetime.
  • Significance: While often mild, untreated or recurrent thrush can lead to discomfort and, in severe cases, systemic infections in immunocompromised individuals.

2. Causes and Risk Factors

  • Causes:
    • Overgrowth of Candida due to disrupted microbiota balance or compromised immune defences.
  • Risk Factors:
    • Local factors: Use of broad-spectrum antibiotics, corticosteroid inhalers, or hormonal changes (e.g., pregnancy).
    • Systemic factors: Diabetes, HIV/AIDS, cancer, chemotherapy, or immunosuppressive therapy.
    • Lifestyle factors: Poor oral hygiene, smoking, or tight clothing (vaginal thrush).

3. Pathophysiology

  • Normally present as part of the microbiota, Candida overgrowth occurs when host defences are compromised or the local environment becomes favourable, leading to infection. Fungal hyphae penetrate the epithelium, causing inflammation and characteristic symptoms.

4. Symptoms and Features

  • Oral Thrush:
    • White, creamy patches on the tongue, inner cheeks, or roof of the mouth.
    • Redness, soreness, and difficulty swallowing in severe cases.
  • Vaginal Thrush:
    • Intense itching, redness, and swelling in the vaginal area.
    • Thick, white discharge resembling cottage cheese.
  • Other Areas:
    • Skin folds: Red, moist patches with scaling or fissures (intertrigo).
    • Nappy rash: Red rash with satellite lesions in infants.

5. Complications

  • Recurrent infections causing significant discomfort.
  • Secondary bacterial infections due to skin breakdown.
  • Systemic candidiasis in immunocompromised individuals, potentially life-threatening.

6. Diagnosis

  • Clinical Features: Diagnosis is primarily clinical based on appearance and symptoms.
  • Laboratory Tests:
    • Microscopic examination of swabs with potassium hydroxide (KOH) preparation.
    • Fungal cultures in recurrent or resistant cases.
    • Blood cultures in suspected systemic candidiasis.

7. Management Overview

  • Goals: Eradicate fungal infection, relieve symptoms, and prevent recurrence.
  • Approach: Localised infections are treated with topical antifungals, while systemic or severe cases may require oral or intravenous antifungal therapy.

8. Treatment Options with Cost (USD)

  • Topical Treatments:
    • Clotrimazole cream (vaginal or skin infections): ~$10–$30 per tube.
    • Nystatin suspension (oral thrush): ~$10–$20 per bottle.
  • Oral Medications:
    • Fluconazole: ~$15–$30 per course.
    • Itraconazole: ~$50–$100 per course.
  • Severe/Systemic Cases:
    • Intravenous antifungals (e.g., amphotericin B): ~$500–$1,500 per course.

9. Advanced Treatment Options with Cost (USD)

  • Refractory or Recurrent Thrush:
    • Long-term fluconazole therapy: ~$15–$30 per month.
    • Echinocandins (e.g., caspofungin): ~$1,000–$2,000 per treatment course for systemic infections.

10. Pharmacological Treatment

  • First-line: Topical antifungals (clotrimazole, nystatin) for localised infections.
  • Oral Agents: Fluconazole for vaginal thrush or recurrent oral thrush.
  • Severe Cases: Intravenous antifungals for systemic candidiasis.

11. Medication Tables

Table 1: Doses and Side Effects

DrugIndicationDoseCommon Side Effects
ClotrimazoleLocalised fungal infectionsApply 2–3 times dailySkin irritation, redness
NystatinOral thrush4–6 mL swished and swallowed 4 times dailyNausea, bitter taste
FluconazoleVaginal or recurrent thrush150 mg as a single dose or 100–200 mg daily for 7–14 daysHeadache, nausea, liver enzyme elevation
ItraconazoleResistant fungal infections200–400 mg dailyGI upset, liver dysfunction
Amphotericin BSystemic candidiasis0.5–1 mg/kg IV dailyFever, chills, kidney toxicity

Table 2: Brand Names and Approximate Costs (USD)

DrugBrand NamesApprox. Cost
ClotrimazoleLotrimin, Canesten$10–$30 per tube
NystatinMycostatin, Nystop$10–$20 per bottle
FluconazoleDiflucan$15–$30 per course
ItraconazoleSporanox$50–$100 per course
Amphotericin BFungizone$500–$1,500 per treatment course

12. Lifestyle Interventions

  • Maintain good oral and genital hygiene to prevent infections.
  • Avoid douching or use of scented products in the genital area.
  • Wear loose, breathable clothing to reduce moisture and irritation.
  • Rinse the mouth after using inhaled corticosteroids to prevent oral thrush.

13. Monitoring Parameters

  • Symptom resolution within 7–14 days for most cases.
  • Monitor liver function for patients on systemic antifungals.
  • Assess for recurrent infections, particularly in those with underlying conditions like diabetes or HIV.

14. Patient Counseling Points

  • Explain the importance of completing the entire course of antifungal therapy, even if symptoms improve.
  • Educate about triggers for thrush, such as antibiotic use or high sugar intake in diabetic patients.
  • Discuss preventive measures, including proper hygiene and maintaining a healthy diet.
  • Advise seeking medical attention for persistent or recurrent infections.

15. Special Populations

  • In Infants: Oral thrush is common and treatable with nystatin suspension; ensure breastfeeding mothers are also evaluated.
  • In Pregnancy: Topical antifungals are preferred; avoid oral fluconazole unless absolutely necessary.
  • In Immunocompromised Individuals: Higher risk of systemic infections; require aggressive treatment and monitoring.

16. Prevention

  • Use probiotics during or after antibiotic therapy to restore normal flora.
  • Ensure proper dental care, including regular cleaning of dentures.
  • Manage underlying conditions like diabetes or immunodeficiency.
  • Avoid sharing personal items like toothbrushes or towels.

17. FAQs

  1. What is thrush?
    Answer: A fungal infection caused by Candida, commonly affecting the mouth, genital area, or skin folds.
  2. What causes thrush?
    Answer: Imbalance in normal flora due to antibiotics, steroids, or weakened immunity.
  3. How is thrush treated?
    Answer: With topical or oral antifungal medications.
  4. Is thrush contagious?
    Answer: Rarely, but it can spread through close contact or shared personal items.
  5. Can thrush recur?
    Answer: Yes, especially in individuals with risk factors like diabetes or immunosuppression.
  6. How can I prevent oral thrush?
    Answer: Maintain good oral hygiene and rinse your mouth after using inhalers.
  7. What are the symptoms of vaginal thrush?
    Answer: Itching, redness, and a thick, white discharge.
  8. Can men get thrush?
    Answer: Yes, particularly as balanitis (inflammation of the penis).
  9. How long does thrush take to resolve?
    Answer: With treatment, symptoms improve within 7–14 days.
  10. Can diet affect thrush?
    Answer: Yes, high sugar intake can promote Candida growth.
  11. Are antifungal creams safe?
    Answer: Yes, for most individuals; consult a doctor if irritation occurs.
  12. Can thrush affect breastfeeding?
    Answer: Yes, oral thrush in infants can spread to the mother’s nipples.
  13. What is systemic candidiasis?
    Answer: A severe fungal infection affecting internal organs, requiring hospitalisation.
  14. When should I see a doctor for thrush?
    Answer: If symptoms persist or recur frequently.
  15. Is fluconazole safe in pregnancy?
    Answer: Topical treatments are preferred; oral fluconazole should only be used if necessary.