hi
Welcome to HCM
i had gone through your father's history and i can understand your concern towards your dad Madavi,
Candidiasis  is a 
fungal infection caused by yeasts from the genus Candida. Candida albicans is the predominant cause of the disease.
Esophageal candidiasis
Patients with esophageal candidiasis may be asymptomatic or may have 1 or more of the following symptoms:
Normal oral mucosa (>50% of patients)
Dysphagia
Odynophagia
Retrosternal pain
Epigastric pain
Nausea and vomiting
Treatment 
1 Esophagial Candidiasis requires systemic therapy with fluconazole for 14-  
    21 days.
2  Parenteral therapy with fluconazole may be required initially if the patient  
    is unable to take oral medications. 
3 Daily suppressive antifungal therapy with fluconazole 100-200 mg/d is 
 effective for preventing recurrent episodes, but it should be used only if 
 the recurrences become frequent or are associated with 
malnutrition due to
  poor oral intake and wasting syndrome. 
4 Recommended alternatives for fluconazole-refractory disease include 
itraconazole, 
voriconazole, caspofungin, micafungin, anidulafungin, and 
amphotericin B.
I hope i have cleared your query
thank you 
take care