History of Present Illness (HPI)

The patient is an 18-year-old female with a history of systemic sclerosis, currently on CellCept, and suppression therapy for cold sores. She presents with a one-day history of sinus congestion, swollen glands, fever of 101.0, chills, body aches, diarrhea, constipation, and a headache. She reports having an elevated temperature earlier in the morning and denies taking any medication for her current symptoms.

Differential Diagnosis

• Single Most Likely Diagnosis
  • Viral upper respiratory infection (e.g., common cold, influenza): The patient's symptoms of sinus congestion, swollen glands, fever, chills, body aches, and headache are consistent with a viral upper respiratory infection, which is a common and likely diagnosis given the acute onset and combination of symptoms.
• Other Likely Diagnoses
  • Bacterial pharyngitis: The presence of swollen glands and fever could suggest a bacterial infection, although the absence of a sore throat makes this less likely.
  • Gastroenteritis: The patient's symptoms of diarrhea and constipation could indicate a gastrointestinal infection, possibly viral in nature.
  • Sinusitis: The sinus congestion and headache could be indicative of sinusitis, which could be either viral or bacterial in origin.
• Do Not Miss Diagnoses
  • Sepsis: Although less likely given the patient's presentation, sepsis is a potentially life-threatening condition that must be considered, especially in immunocompromised patients (e.g., those on immunosuppressive therapy like CellCept).
  • Influenza: Given the time of year and the patient's symptoms, influenza is a critical diagnosis not to miss, as it can lead to severe complications, especially in patients with underlying health conditions.
  • CellCept-related complications: As the patient is on immunosuppressive therapy, there is a risk of opportunistic infections or other complications related to her medication.
• Rare Diagnoses
  • Connective tissue disease flare: Although the patient has a history of systemic sclerosis, a flare of her underlying disease could potentially explain some of her symptoms, though this would be less likely given the acute onset and nature of the symptoms.
  • Immunocompromised-related infections: Given the patient's immunosuppressed state, rare opportunistic infections could be considered, though these would be less likely without additional specific symptoms or findings.