Oral Candidiasis

Oral candidiasis is an opportunistic fungal infection affecting the oral mucosa caused predominantly by Candida albicans, a commensal organism normally present in the oral cavity. Disease occurs when local or systemic immunity becomes impaired, allowing fungal overgrowth.

Acute oral candidiasis (thrush) commonly affects neonates, malnourished individuals, immunocompromised patients (especially HIV/AIDS), patients receiving prolonged antibiotic therapy, corticosteroids, chemotherapy, or individuals using poorly fitting dentures.

Chronic forms may lead to persistent keratinized white plaques and mucosal inflammation.

Pathophysiology

Candida albicans exists in yeast and hyphal forms. Under normal conditions, host immunity and oral microbial flora prevent pathogenic proliferation.

Predisposing factors disrupt this balance through:

• Reduction of cellular immunity (HIV infection, malignancy)

• Altered oral microbiome following antibiotic therapy

• Reduced salivary flow (xerostomia)

• Hyperglycemic environment in diabetes mellitus

• Local mucosal trauma from dentures

• Immature immune system in neonates

The organism adheres to epithelial cells, transforms into invasive hyphae, and penetrates mucosal surfaces causing inflammation, epithelial desquamation, and formation of pseudomembranous plaques.

Risk Factors

Systemic Factors

• HIV/AIDS

• Diabetes mellitus

• Malnutrition

• Extremes of age (neonates and elderly)

• Malignancy

• Immunosuppressive therapy

• Long-term corticosteroid therapy

• Broad-spectrum antibiotic use

Local Factors

• Poor oral hygiene

• Denture use

• Xerostomia

• Smoking

• Inhaled corticosteroids

• Oral mucosal trauma

Clinical Classification

1. Pseudomembranous Candidiasis (Thrush)

• Creamy white plaques resembling curdled milk

• Easily wiped off leaving erythematous or bleeding surface

• Common on:

  • Tongue

  • Buccal mucosa

  • Palate

  • Oropharynx

2. Erythematous (Atrophic) Candidiasis

• Diffuse red inflamed mucosa

• Burning sensation

• Loss of papillae on tongue

• Often follows antibiotic therapy

3. Hyperplastic (Chronic) Candidiasis

• Thick white leukoplakia-like plaques

• Not easily scraped off

• May carry premalignant potential

• Requires biopsy if persistent

4. Angular Cheilitis

• Painful fissures at mouth angles

• Erythema and maceration

• Often associated with:

  • Denture stomatitis

  • Nutritional deficiency

  • HIV infection

Signs and Symptoms

• White or yellow oral patches

• Burning mouth sensation

• Cotton-like feeling in mouth

• Oral soreness or pain

• Dysphagia or odynophagia

• Loss or alteration of taste

• Cracked lips or angular fissures

• Dry mouth

Neonates may present with:

• Feeding difficulty

• Irritability during breastfeeding

Diagnostic Criteria

Diagnosis is primarily clinical.

Typical findings:

• Removable white plaques

• Erythematous mucosa after scraping

• Associated risk factors

Persistent lesions require further evaluation.

Investigations

Routine investigations are not required in uncomplicated cases.

Indications for Investigation

• Recurrent infection

• Treatment failure

• Suspicion of malignancy

• Immunosuppression

Recommended Tests

• Oral swab microscopy and culture

• Potassium hydroxide (KOH) preparation

• Biopsy (chronic hyperplastic lesions)

• Endoscopy (suspected esophageal candidiasis)

• Blood glucose testing

• HIV testing where indicated

Management

A. Non-Pharmacological Management

• Maintain good oral hygiene

• Clean dentures daily and remove at night

• Sterilize feeding bottles and pacifiers

• Rinse mouth after inhaled steroid use

• Reduce sugar intake

• Control underlying diseases (e.g., diabetes)

• Nutritional rehabilitation

B. Pharmacological Treatment

(According to Tanzania Standard Treatment Guidelines – 2022)

First-Line (Topical Therapy)

Nystatin oral suspension

• 100,000 IU/ml

• 1 ml held in mouth ≥3 minutes before swallowing

• 4 times daily after feeds

• Continue 5–7 days after clinical cure

OR

Miconazole oral gel

• 25 mg/ml

• Apply 5–10 ml in mouth

• Hold ≥60 seconds before swallowing

• 4 times daily

Second-Line / Severe Disease

Fluconazole

• Adults: 150 mg orally once daily for 7–14 days

• Children: 3–6 mg/kg/day

OR

Itraconazole

• 200 mg orally once daily for 7–14 days

Special Populations

Neonates

• Nystatin suspension preferred

• Treat breastfeeding mother's nipples if infected

HIV/AIDS Patients

• High recurrence rate

• Follow national HIV management guidelines

• Consider systemic antifungal therapy

Denture Wearers

• Apply antifungal to denture surface

• Overnight denture removal mandatory

Complications

• Esophageal candidiasis

• Feeding difficulty in infants

• Chronic mucosal inflammation

• Malnutrition

• Recurrent infection in immunocompromised patients

Prevention

• Proper oral hygiene practices

• Glycemic control in diabetics

• Judicious antibiotic use

• Mouth rinsing after steroid inhalers

• Regular denture cleaning

• Early HIV screening in recurrent cases

• Adequate nutrition

Patient Education

• Complete full course of treatment

• Do not stop medication after symptom improvement

• Clean mouth after meals

• Avoid self-medication

• Seek care if symptoms persist beyond 7–10 days

• Replace or adjust ill-fitting dentures

Prognosis

With appropriate therapy, oral candidiasis usually resolves within 7–14 days. Recurrence indicates underlying systemic disease requiring evaluation.