Overview of Infectious Mononucleosis and Treatments

Nasal Cautery

• Silver nitrate sticks are used to cauterize bleeding vessels.

Post-Treatment Care

• Naseptin Nasal Cream contains chlorhexidine and neomycin.
• Apply Naseptin Nasal Cream four times daily for 10 days.
• It is used to reduce crusting, inflammation, and potential infection.
• Do not use Naseptin Nasal Cream if the patient has a peanut or soya allergy.

Overview of Infectious Mononucleosis (IM)

• Infectious mononucleosis (IM) is caused by the Epstein-Barr virus (EBV).
• IM is commonly known as “glandular fever” or “mono.”
• The virus is spread through saliva, often by kissing or sharing items like cups or toothbrushes.
• EBV can be infectious weeks before symptoms appear and intermittently for the patient's lifetime.
• Most people contract EBV in childhood with few symptoms.
• When infection occurs in adolescents or young adults, it results in more symptomatic disease (IM).

Key Features of Infectious Mononucleosis (IM)

• Common symptoms include fever, sore throat, fatigue, swollen lymph nodes, red and swollen tonsils with white or yellow coating, and enlarged spleen.
• A distinctive itchy rash can develop in patients who take amoxicillin or cephalosporins during IM.
• This rash is an EBV reaction to the antibiotics.

Diagnosis of Infectious Mononucleosis (IM)

• Heterophile antibodies are non-specific but help confirm IM when EBV-specific tests are unavailable.
• The Monospot Test uses horse red blood cells that react with heterophile antibodies in the patient's blood.
• The Paul-Bunnell Test uses sheep red blood cells.
• Both tests have high specificity for IM (almost 100%).

Blood Loss

• The most common cause of blood loss in adults is bleeding from the gastrointestinal (GI) tract.
• In menstruating women, heavy periods (menorrhagia) are a common cause.
• In non-menstruating women and men, GI tract bleeding is often the source.
• Potential sources of GI bleeding include cancer of the stomach or bowel, oesophagitis, gastritis, peptic ulcers, inflammatory bowel disease, and angiodysplasia.

Dietary Insufficiency in Children

• High growth demands in children often exceed dietary iron intake.
• Pica (eating non-food items like soil) can be a sign of iron deficiency in children.

Absorption Mechanism

• Iron is absorbed primarily in the duodenum and jejunum.
• Iron is absorbed in its soluble ferrous (Fe2+) form.
• Stomach acid helps maintain the ferrous form.
• Low stomach acid can hinder iron absorption by converting it to insoluble ferric (Fe3+) form.
• Conditions like coeliac disease or Crohn’s disease in the duodenum or jejunum impair iron absorption.

Testing for Iron Levels

• Transferrin is a protein that binds and transports iron in the blood.
• Total Iron-Binding Capacity (TIBC) is a measure of the amount of transferrin available to bind iron.
• Transferrin Saturation is the percentage of transferrin bound with iron.
• Ferritin is a protein that stores iron within cells and acts as an acute-phase protein.
• Low Ferritin is highly indicative of iron deficiency.
• High Ferritin could indicate inflammation, liver disease, iron supplements, or haemochromatosis.
• Serum Iron levels fluctuate throughout the day and rise after meals rich in iron.

Interpretation of Iron Markers

• Iron Deficiency is indicated by increased TIBC and transferrin levels, and decreased transferrin saturation.
• Iron Overload is indicated by high serum iron, transferrin saturation, and ferritin, with low TIBC.

Iron Chelation

• Iron chelation is essential to prevent complications from iron overload.

Surgical Interventions for Infectious Mononucleosis

• Splenectomy may be needed for severe splenomegaly.
• Cholecystectomy may be needed for gallstones.

Curative Option for Infectious Mononucleosis

• Bone marrow transplant is a curative option in severe cases, particularly for thalassaemia major.

Overview of Sickle Cell Anaemia

• Sickle cell anaemia is an autosomal recessive genetic disorder.
• The disorder causes red blood cells (RBCs) to become sickle or crescent-shaped due to abnormal haemoglobin S (HbS).
• The sickle shape makes RBCs more fragile, leading to haemolytic anaemia and sickle cell crises.

Pathophysiology of Sickle Cell Anaemia

• Haemoglobin S (HbS) replaces normal adult haemoglobin (HbA) in affected individuals.
• The mutation affects the beta-globin gene on chromosome 11.
• Sickle Cell Trait occurs when an individual carries one abnormal copy of the gene (asymptomatic).
• Sickle Cell Disease occurs when an individual carries two abnormal copies of the gene (symptomatic).

Relation to Malaria

• Individuals with sickle cell trait are more resistant to malaria.
• This selective advantage explains the higher prevalence of the gene in regions with a history of malaria.

Screening for Sickle Cell Anaemia

• Newborn screening is conducted using a blood spot test at around 5 days of age.
• Antenatal screening is offered to pregnant women at high risk of carrying the sickle cell gene.

Complications of Sickle Cell Anaemia

• Anaemia
• Increased infection risk
• Chronic kidney disease
• Sickle cell crises
• Acute chest syndrome
• Stroke
• Avascular necrosis
• Pulmonary hypertension
• Gallstones
• Priapism

Sickle Cell Crisis

• Sickle cell crises are acute exacerbations of the disease, which can range from mild to life-threatening.
• Triggers for crises include dehydration, infection, stress, or cold weather.

Management of Sickle Cell Crisis

• Supportive care includes hospital admission, hydration (IV fluids), warmth, and pain management.
• Avoid NSAIDs in patients with renal impairment.

Types of Sickle Cell Crisis

• Vaso-occlusive Crisis (VOC): Sickle cells obstruct capillaries, causing distal ischaemia.
• Aplastic Crisis: Temporary decrease in RBC production.
• Splenic Sequestration Crisis: Excessive pooling of blood in the spleen.
• Hyperhemolytic Crisis: Increased rate of RBC destruction.

Small Cell Lung Cancer (SCLC)

• SCLC is primarily treated with chemotherapy and radiotherapy.
• It has a poorer prognosis than Non-Small Cell Lung Cancer (NSCLC).

Endobronchial Treatments

• Stents or debulking can provide palliative relief for airway obstruction.

Chest Drains

• Chest drains are used post-thoracic surgery to remove air and fluid, allowing lung expansion.
• The drain is placed underwater to prevent air reentry; bubbles allow air to escape while preventing backflow.
• The water in the chest drain swings with respiration due to pressure changes in the chest.

Overview of Pleural Effusion

• A pleural effusion is a collection of fluid in the pleural space between the lungs and chest wall.
• Exudative Effusion has high protein content (> 30 g/L) due to inflammatory processes.
• Transudative Effusion has low protein content (< 30 g/L) due to non-inflammatory processes.

Light’s Criteria for Exudative Effusions

• These criteria are used to determine if an effusion is exudative:
  • Pleural fluid protein / serum protein > 0.5
  • Pleural fluid LDH / serum LDH > 0.6
  • Pleural fluid LDH > 2/3 of the upper limit of normal for serum LDH

Causes of Pleural Effusion

• Exudative Causes:
  • Cancer (e.g., lung cancer, mesothelioma)
  • Infection (e.g., pneumonia, tuberculosis)
  • Rheumatoid Arthritis
• Transudative Causes:
  • Congestive Cardiac Failure
  • Hypoalbuminaemia
  • Hypothyroidism
  • Meigs Syndrome (a triad of a benign ovarian tumour, pleural effusion, and ascites)

Presentation of Pleural Effusion

• The primary symptom is shortness of breath.
• Examination findings include:
  • Dullness to percussion over the effusion area
  • Reduced breath sounds
  • Tracheal deviation away from the effusion in cases of large effusions

Investigations for Pleural Effusion

• Tests for immune response (to detect exposure, latent, or active TB) include:
  • Mantoux Test (skin test using purified protein derivative (PPD))
  • Interferon-Gamma Release Assay (IGRA) (blood test to detect immune response to TB antigens)
• Tests for active disease include:
  • Chest X-ray
  • Sputum Cultures

Diagnostic testing for Tuberculosis

• Mantoux Test:
  • A small amount of tuberculin (TB proteins) is injected into the forearm, creating a small raised bleb.
  • After 72 hours, the induration (firm swelling) at the injection site is measured.
  • An induration of ≥5mm is considered positive, indicating TB exposure or infection.
• Interferon-Gamma Release Assays (IGRA):
  • Blood is mixed with TB antigens.
  • Sensitized white blood cells from prior TB exposure release interferon-gamma.
  • A positive result indicates prior contact with M. tuberculosis.
• Chest X-Ray Findings:
  • Primary TB: Patchy consolidation, pleural effusions, and hilar lymphadenopathy.
  • Reactivated TB: Patchy or nodular consolidation with cavitation, usually in the upper lung zones.
  • Miliary TB: Characterized by "millet seed" appearance—small, uniformly distributed nodules (1-3mm) across lung fields
• Cultures:
  • Ideally collected before initiating treatment to assess drug resistance.
  • Collection methods include:
    • Sputum Cultures (three separate samples required)
    • Blood Cultures (special bottles for Mycobacterium blood cultures)
    • Lymph Node Biopsy or Aspiration
  • Special techniques for collecting sputum include:
    • Sputum induction (nebulized saline)
    • Bronchoscopy with lavage (if sputum production is low)
• Nucleic Acid Amplification Tests (NAAT):
  • Detects TB DNA for quicker diagnosis than traditional culture.
  • Employed in high-risk patients (e.g., HIV positive, children under 16) and suspected drug-resistant cases.

Treatment of Tuberculosis

• Latent TB:
  • Options include:
    • Isoniazid and Rifampicin: Taken for 3 months.
    • Isoniazid: Taken alone for 6 months.

This quiz covers key points about infectious mononucleosis, including its causes, common symptoms, and transmission methods. It also discusses treatment options such as nasal cautery and the use of Naseptin Nasal Cream for post-treatment care. Test your knowledge on this viral infection and its management.