What is the likely diagnosis and appropriate management for a generally healthy adult with negative HIV tests, normal imaging and laboratory studies, resting tachycardia, persistent dizziness, fatigue, hypersomnolence, subjective fever, polyuria, and depressive symptoms?

Diagnosis and Management of Somatic Symptoms Following Prolonged HIV-Related Anxiety

Primary Diagnosis

You are experiencing major depressive disorder with somatic symptoms following a prolonged period of severe health anxiety, not an undiagnosed medical condition. Your extensive negative HIV testing (4th generation, RNA, and DNA tests), normal imaging studies, and normal laboratory results definitively rule out HIV infection and other serious organic pathology 1. The constellation of persistent dizziness, fatigue, hypersomnolence, subjective fever without objective temperature elevation, polyuria, persistent low mood, and anhedonia meets diagnostic criteria for major depressive disorder, which requires at least 2 weeks of depressed mood or loss of interest plus additional symptoms including fatigue, sleep disturbance, and difficulty concentrating 2.

Understanding Your Symptoms

Psychiatric Manifestations

• Depression is extremely common among individuals with prolonged health anxiety and is characterized by the exact symptoms you describe: persistent fatigue, excessive sleepiness, loss of interest in activities, and low mood 1.
• Your symptoms emerged after 3-4 months of severe anxiety, which represents the typical threshold for anxiety-related exhaustion to manifest as clinical depression 2.
• The subjective fever without objective temperature elevation (your actual temperature is 36.6°C, which is normal) is a classic somatic manifestation of anxiety and depression, not infectious disease 1.

Physical Examination Findings

• Your elevated resting heart rate (90+ bpm) is consistent with persistent anxiety and does not indicate cardiac pathology given your normal blood pressure and absence of other cardiovascular symptoms 1.
• Frequent urination in the context of anxiety and depression often represents psychogenic polydipsia or anxiety-related bladder sensitivity rather than metabolic disease, especially given your normal comprehensive metabolic panel and renal function 1.

Immediate Management Algorithm

Step 1: Initiate Antidepressant Therapy

• Start escitalopram 10 mg daily, which is FDA-approved for major depressive disorder and generalized anxiety disorder 2.
• Escitalopram specifically addresses both the depressive symptoms (fatigue, anhedonia, low mood) and the underlying anxiety that precipitated your condition 2.
• Expect 4-6 weeks for full therapeutic effect, though some improvement in anxiety symptoms may occur within 2 weeks 2.

Step 2: Cognitive Behavioral Therapy

• Engage in cognitive behavioral therapy (CBT) specifically targeting health anxiety and somatic symptom disorder, as this addresses the cognitive distortions that maintain your symptoms even after negative medical testing 1.
• CBT will help you reframe the catastrophic thinking patterns that developed during your 3-4 months of HIV-related anxiety 1.

Step 3: Sleep Hygiene and Fatigue Management

• Your hypersomnolence represents depression-related hypersomnia, not a primary sleep disorder, and will improve with antidepressant treatment 2.
• Maintain consistent sleep-wake times and avoid excessive daytime sleeping, which paradoxically worsens fatigue in depression 2.

Step 4: Reassurance and Education

• Accept that your extensive negative testing definitively excludes HIV infection: multiple 4th generation tests, RNA tests, and DNA tests provide >99.9% certainty of your HIV-negative status 1.
• Understand that continued medical testing will not resolve your symptoms and may perpetuate health anxiety 1.

What NOT to Do: Critical Pitfalls

• Do not pursue additional HIV testing or other infectious disease workup, as this reinforces health anxiety and delays appropriate psychiatric treatment 1.
• Do not attribute your symptoms to undiagnosed medical illness, as your comprehensive evaluation (head CT, chest CT, abdominal ultrasound, gastroscopy, complete blood count, comprehensive metabolic panel, liver/kidney function) has excluded serious pathology 1, 3.
• Do not wait for symptoms to resolve spontaneously, as untreated major depressive disorder typically persists for 6-12 months and significantly impairs quality of life 2.
• Avoid benzodiazepines for long-term anxiety management, as they carry dependence risk and do not address the underlying depression 2.

Monitoring and Follow-Up

• Schedule follow-up at 2 weeks after starting escitalopram to assess tolerability and early response, then monthly until symptom resolution 2.
• Monitor for worsening depression or emergence of suicidal ideation, particularly in the first 4-8 weeks of antidepressant treatment 2.
• Your elevated heart rate should normalize as anxiety and depression improve; no cardiac workup is needed given normal blood pressure and absence of chest pain or palpitations 1.

Expected Outcome

• With appropriate treatment, expect significant improvement in fatigue, mood, and somatic symptoms within 6-8 weeks 2.
• The subjective fever sensation, dizziness, and polyuria will resolve as your depression and anxiety improve 2.
• Continue antidepressant therapy for at least 6-12 months after symptom resolution to prevent relapse 2.