Pyrexia of unknown origin | Figure 1

Pyrexia of Unknown Origin

A 45-year-old male presented with a complaint of fever for 45 days, which is high grade with no focus of fever found on history. Clinical examination revealed a temperature of 104°F and a pulse of 120 beats per minute. He was normotensive and had normal glycemic levels. All systemic examinations were unremarkable.

Initial lab investigations showed:

Tests for Hepatitis B and C were negative, liver function tests (LFTs) were normal, renal function tests (RFTs) were normal, serum electrolytes were normal and blood cultures were negative. Brucella antibodies were within normal limits; ECG and echo results were normal. ANA was positive, but ENA profile was negative. HRCT of the chest revealed interstitial pneumonitis. Vitamin B12 levels were low, while folic acid levels were normal. Bone marrow examination showed hypocellular aplasia.

The patient was initially treated with:

However, the fever persisted. Antibiotic coverage was administered along with antimalarial treatment, but the fever and bicytopenia persisted.

Similar Cases:

  1. Female patient, 14 years old
    Presented at 6 months with high-grade fever, resistant microcytic hypochromic anemia, failure to thrive, and huge splenomegaly. Also suffered from:

    • Exam: Pallor, weight, and height were below the 3rd percentile, absence of secondary sexual characters.
    • Investigations: Microcytic hypochromic anemia, normal ferritin with low iron levels, negative hemolysis tests, normal kidney and liver functions, normal bone marrow examination, elevated immunoglobulin levels, negative Leishmania antibodies, and normal thyroid and growth hormone levels.

  2. 33-year-old male
    Initially diagnosed with malaria falciparum 2 weeks ago and treated with anti-malarials. He presented again with continuous fever for 20 days. Lab results indicated:

    • Peripheral smear showed:
      • Hb: 8.9 g/dl
      • TLC: 2.28
      • Platelet: 45
      • MCV: 88
      • Anisocytosis
      • RDW: 13.5
      • Dengue negative
    • Creatinine: 4; GFR: 17.8
    • LFTs showed total bilirubin 0.95, ALT 119, and albumin 3.04.
    • Urine r/e showed 3 red cells and ++ albuminuria; LDH raised to 3599, calcium 8, uric acid 9, ultrasound revealed mild splenomegaly.

  3. 27-year-old female
    G2P1001, in the second trimester of current pregnancy, complained of fever, fatigue, and chin numbness for the last week, confirmed by physical examination. Hepatosplenomegaly was noted. Laboratory tests reported the presence of blasts in the peripheral smear, confirmed as Pre-B-ALL based on flow cytometry results and positive cytogenetics workup for t(9;22).

  4. 52-year-old man
    Presented with a 20-minute history of chest pain radiating to the left shoulder and neck, associated with dyspnea and diaphoresis. He had a history of hypertension and long-term smoking. Physical examination revealed bibasilar crackles. An ECG was performed and he was promptly referred to the emergency department.

  5. 28-year-old woman
    Presented with 3-day history of intense pruritus over the lower back, caring for dogs rescued from the streets. Examination revealed multiple small vesicles on the lumbar region and left gluteal area.

  6. 4-month-old male infant
    Presented with skin lesions localized to the chin for 3 days, revealed multiple pustules with surrounding inflammatory signs.

  7. Late teenage patient
    Presented after a collapse, with no chest pain or previous cardiac history.

This document outlines various cases with pyrexia of unknown origin, differing in presentation and laboratory findings, indicating the need for tailored diagnostic and therapeutic approaches.