Differential Diagnosis

• Single most likely diagnosis
  • Tuberculous Lymphadenitis: The patient's symptoms, including swollen tonsils with white spots, neck lymphadenopathy that reduced significantly after a course of antibiotics but then developed hardness and swelling, suggest a possible infection. The fact that the lymphadenopathy reduced by 90% after antibiotic treatment but then progressed to hardness and swelling over the previously enlarged lymph nodes could indicate a partially treated bacterial infection or, more likely, a mycobacterial infection such as tuberculosis, which is common in India and can cause lymphadenitis.
• Other Likely diagnoses
  • Reactive Lymphadenitis: This condition could have been triggered by the initial infection (possibly streptococcal given the tonsillar symptoms) and could explain the lymph node enlargement and subsequent reduction with antibiotic treatment. However, the persistence and hardness of the lymph nodes might suggest a more chronic or specific infection.
  • Lymphoma: Although less likely given the initial response to antibiotics, lymphoma cannot be ruled out without further investigation, especially given the persistence of lymph node abnormalities. The intermittent ear pain and headache could be non-specific symptoms but also warrant consideration of a more serious underlying condition like lymphoma.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • HIV Infection: Given the patient's symptoms of recurrent infections (tonsillitis, possible otitis media suggested by ear pain), it's crucial to consider HIV as an underlying immunocompromised state that could predispose to opportunistic infections, including TB, and affect the lymph nodes.
  • Sarcoidosis: Although less common, sarcoidosis can cause lymphadenopathy and could be considered in the differential, especially if other systemic symptoms are present.
• Rare diagnoses
  • Kikuchi-Fujimoto Disease: A rare, self-limiting condition that causes lymphadenitis, more common in young Asian women but can occur in anyone. It might be considered if other diagnoses are ruled out.
  • Kimura Disease: Another rare condition that causes lymphadenopathy and eosinophilia, more common in Asian males. It's characterized by the presence of eosinophilia and IgE elevation, which might not be directly suggested by the current symptoms but could be a consideration in a differential diagnosis.

Each of these diagnoses requires further investigation, including imaging studies (e.g., ultrasound or CT scan of the neck), blood tests (e.g., complete blood count, erythrocyte sedimentation rate, interferon-gamma release assay for TB), and potentially a lymph node biopsy to establish a definitive diagnosis.