Differential Diagnosis for a 47-year-old Male with UC

Single Most Likely Diagnosis

• Oral Thrush (Candidiasis): Given the patient's history of ulcerative colitis (UC) and recent gastrointestinal symptoms, followed by weakness, altered taste, and specific oral findings (white patches on the tongue and a red hard palate), oral thrush is a highly plausible diagnosis. The use of corticosteroids or other immunosuppressive medications for UC could predispose him to fungal infections like candidiasis.

Other Likely Diagnoses

• Nutritional Deficiencies: The patient's symptoms of weakness and altered taste, combined with a history of vomiting and diarrhea, suggest possible nutritional deficiencies, particularly of vitamins and minerals like B12, iron, or zinc, which are crucial for taste and overall health.
• Medication Side Effects: Given the patient's UC, he may be on medications that could cause side effects like altered taste or oral changes, such as sulfasalazine or other immunosuppressants.
• Gastrointestinal Infection: Although the patient's vomiting and diarrhea have resolved, a recent gastrointestinal infection could still be contributing to his current symptoms, especially if the infection was caused by a pathogen that can lead to prolonged or secondary infections.

Do Not Miss Diagnoses

• Adrenal Insufficiency: This is a potentially life-threatening condition that could occur in patients on long-term corticosteroid therapy for UC. Symptoms like weakness could be indicative of adrenal insufficiency, making it crucial not to miss this diagnosis.
• Sepsis: Although less likely given the resolution of the gastrointestinal symptoms, sepsis is a condition that must always be considered, especially in immunocompromised patients, as it can present with non-specific symptoms like weakness and can be life-threatening if not promptly treated.

Rare Diagnoses

• Oral Lichen Planus: This is an inflammatory condition that can affect the mucous membranes inside the mouth and could potentially cause some of the patient's symptoms, although it is less likely given the acute onset and specific findings.
• Pemphigus: A rare autoimmune disease that causes blistering of the skin and mucous membranes, which could potentially explain some of the oral findings, though it is much less common and would typically present with more widespread and severe symptoms.