7.2 Pediatric Infectious Diseases and Common Childhood Illnesses

Introduction to Pediatric Infectious Diseases & Common Childhood Illnesses

In pediatric nursing, managing infectious diseases and common childhood illnesses represents a cornerstone of clinical practice and is a heavily tested domain on the Philippine Nurse Licensure Examination (PNLE). Under Republic Act No. 9173 (The Philippine Nursing Act of 2002), Section 28, registered nurses are legally and professionally mandated to initiate independent nursing assessments, implement nursing care, administer prescribed medical treatments, monitor clinical responses, and provide comprehensive health education.

In the Philippines, the Department of Health (DOH) integrates the World Health Organization's (WHO) Integrated Management of Childhood Illness (IMCI) guidelines. IMCI provides a systematic, evidence-based approach to assessing, classifying, and managing the most common causes of childhood morbidity and mortality, including measles, diarrhea-induced dehydration, and acute respiratory infections. This section delivers a detailed clinical analysis of these major childhood conditions, focusing on nursing assessment, pathophysiology, transmission prevention, and evidence-based management.

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Common Viral Exanthems in Pediatrics

Viral exanthems are eruptive skin rashes associated with systemic viral infections. They require precise clinical differentiation to apply correct isolation precautions and prevent hospital-acquired transmissions.

1. Measles (Rubeola)

• Causative Agent & Transmission: Caused by the Measles virus, a paramyxovirus of the genus Morbillivirus. Transmission is highly contagious and occurs via airborne droplets or direct contact with nasal and throat secretions. The virus can remain suspended in the air of a room for up to two hours after the infected individual has left.

• Clinical Presentation: The prodromal phase features a high fever and the classic "3 Cs":

  1. Coryza: Acute rhinitis and nasal inflammation with profuse drainage.
  2. Cough: Severe, harsh, hacking, non-productive cough.
  3. Conjunctivitis: Inflamed, watery eyes with severe photophobia.

  A pathognomonic finding is Koplik spots—tiny, irregular, bluish-white spots on an erythematous background on the buccal mucosa opposite the lower molars, appearing 2 to 3 days before the generalized rash. The measles rash is an erythematous maculopapular eruption that typically begins at the hairline or behind the ears and spreads cephalocaudally (downwards to the face, neck, trunk, and eventually the extremities). As the rash fades, it undergoes brownish desquamation and fine scaling.

• Nursing and Medical Management:

  • Strict Isolation: Immediately place the patient on Airborne Precautions. This requires a negative-pressure isolation room and the use of a fit-tested N95 respirator mask by all healthcare workers entering the room.
  • Vitamin A Supplementation: Essential for all children diagnosed with measles. DOH guidelines recommend oral Vitamin A administration (dose based on age: 50,000 IU for infants <6 months; 100,000 IU for infants 6-11 months; 200,000 IU for children ≥12 months, given immediately on diagnosis and repeated the following day). Vitamin A therapy reduces the severity of ocular damage, prevents blindness, and significantly decreases overall mortality from measles-associated complications such as pneumonia and croup.
  • Supportive Care: Provide cool-mist humidification for cough, keep room lights dimmed to manage photophobia, and administer non-salicylate antipyretics (acetaminophen) for fever.

2. Rubella (German Measles)

• Causative Agent & Transmission: Caused by the Rubella virus (a togavirus). It is transmitted via nasopharyngeal secretions through direct contact or Droplet Precautions.
• Clinical Presentation: Typically a mild disease in children, presenting with a low-grade fever, lymphadenopathy (prominently postauricular, suboccipital, and cervical nodes), and a pinkish-red, non-confluent maculopapular rash that spreads rapidly downward from the face.
• Congenital Rubella Syndrome (CRS): While rubella is benign in children, it has severe teratogenic risks if contracted by a pregnant woman during the first trimester. CRS features include:
  • Sensorineural deafness (most common defect).
  • Ophthalmic defects (cataracts, microphthalmia, congenital glaucoma).
  • Cardiac defects (patent ductus arteriosus [PDA], pulmonary artery stenosis).
  • Neurological deficits (microcephaly, developmental delay).
• Nursing Management: Implement Droplet Precautions. Because of the extreme teratogenic danger, pregnant healthcare workers must never be assigned to care for clients with suspected or confirmed Rubella. Educate parents on the importance of the MMR (Measles, Mumps, Rubella) vaccine, administered under the DOH National Immunization Program (NIP) at 9 months and 12-15 months of age.

3. Varicella-Zoster Virus (Chickenpox)

• Causative Agent & Transmission: Caused by the Varicella-Zoster Virus (VZV), a herpesvirus. Transmission occurs via direct contact with ruptured vesicular fluid, airborne secretions, or contaminated items.
• Clinical Presentation: The rash progresses rapidly in stages: macules $\rightarrow$ papules $\rightarrow$ clear, fluid-filled vesicles (often described as "dewdrops on a rose petal") $\rightarrow$ pustules $\rightarrow$ crusts. The lesions are highly pruritic and appear in successive crops, meaning lesions in multiple stages of development are simultaneously present on the child's body.
• Nursing Management & Isolation:
  • Isolation Precautions: Implement strict Airborne and Contact Precautions. The patient remains contagious from 1-2 days before the rash appears until all lesions have completely crusted and scabbed over.
  • Scratch Prevention: Apply calamine lotion, administer antihistamines as prescribed, keep the child’s fingernails cut short and clean, and utilize mittens or soft elbow restraints if necessary. Preventing scratching is critical to avoid secondary bacterial infections (such as Staphylococcus aureus or Streptococcus pyogenes cellulitis), which can lead to permanent scarring and sepsis.
  • Aspirin Contraindication: Never administer aspirin (acetylsalicylic acid) or products containing salicylate to children with varicella (or any viral infection). Doing so is strongly linked to Reye's Syndrome, a rare but life-threatening condition characterized by acute encephalopathy and fatty degeneration of the liver. Use acetaminophen for fever management instead.

4. Mumps (Epidemic Parotitis)

• Causative Agent & Transmission: Caused by the Mumps rubulavirus. It is transmitted via saliva and respiratory secretions through Droplet Precautions or direct contact.
• Clinical Presentation: Characterized by fever, headache, malaise, and unilateral or bilateral painful swelling of the salivary glands, most commonly the parotid glands (parotitis). The swelling can obscure the angle of the jaw and is aggravated by chewing or swallowing acidic foods.
• Complications:
  • Orchitis: Painful testicular inflammation, occurring in post-pubertal males; it is usually unilateral, but bilateral involvement can lead to sterility.
  • Oophoritis: Ovarian inflammation in post-pubertal females.
  • Aseptic Meningitis: Manifests as nuchal rigidity, headache, and lethargy.
  • Sensorineural Hearing Loss: Can be sudden and permanent.
• Nursing Management: Implement Droplet Precautions. Provide pain management, apply warm or cold compresses to the swollen neck/jaw area, encourage hydration, and offer a soft, bland diet. Avoid acidic, spicy, or sour foods (such as citrus juices) as they stimulate saliva production, which causes intense pain.

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Pediatric Gastroenteritis and Dehydration

Acute gastroenteritis is a leading cause of pediatric hospitalizations and mortality in developing countries. Dehydration occurs rapidly in young children due to their higher percentage of total body water, higher metabolic rate, and immature renal conservation mechanisms.

Degrees of Dehydration Assessment

Nurses must rapidly assess the degree of dehydration using the following clinical indicators:

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Rehydration Protocols: ORT and IV Resuscitation

The management of pediatric dehydration is determined by the severity classification:

1. Oral Rehydration Therapy (ORT) for Mild to Moderate Dehydration

ORT is the primary, most cost-effective clinical intervention recommended by DOH and WHO.

• ORS Composition: The WHO-recommended low-osmolarity Oral Rehydration Salts (ORS) formula consists of:

  • Sodium: 75 mEq/L
  • Glucose: 75 mmol/L (provides cotransport of sodium across the intestinal lumen)
  • Chloride: 65 mEq/L
  • Potassium: 20 mEq/L
  • Citrate: 10 mmol/L

  The low osmolarity (245 mOsm/L) is crucial because it matches physiological osmolarity, preventing osmotic drag of water back into the intestinal lumen, thereby reducing stool volume and emesis.

• Administration Guidelines:

  • Mild Dehydration: Administer 50 mL/kg of ORS over 4 hours.
  • Moderate Dehydration: Administer 100 mL/kg of ORS over 4 hours.
  • Method of Delivery: Administer in frequent, small amounts (e.g., 5 to 15 mL every 5 to 10 minutes) using a spoon, syringe, or small cup. Giving large volumes at once can trigger vomiting due to gastric distension.
  • Ongoing Losses: For each diarrheal stool or episode of vomiting, add 10 mL/kg of ORS for infants, and 100-200 mL for older children.
  • Emesis Protocol: If the child vomits during administration, pause ORT for 10 minutes to allow gastric irritation to subside, then resume at a much slower rate (e.g., 1 teaspoon or 5 mL every 2 to 3 minutes).
  • Note: Avoid clear liquids with high sugar content (soda, apple juice, sports drinks) as their high osmolarity draws fluid into the bowel, worsening diarrhea.

2. Intravenous (IV) Fluid Resuscitation for Severe Dehydration

Severe dehydration is a medical emergency that can lead to hypovolemic shock.

• Indications: Indicated when the child is lethargic, comatose, has an altered level of consciousness (aspiration risk), has an intestinal ileus, or shows signs of shock (hypotension, cold extremities).
• Fluid Choice: Always utilize isotonic crystalloids, specifically 0.9% Normal Saline (NS) or Lactated Ringer's (LR). Never use hypotonic solutions (e.g., 0.45% NS or D5W) for bolus resuscitation, as they can cause rapid shifts of water into brain cells, leading to cerebral edema and seizures.
• Bolus Volume & Infusion Protocol:
  • Administer an initial bolus of 20 mL/kg of the isotonic crystalloid over 10 to 20 minutes (or as a rapid push in severe shock).
  • Reassess clinical markers (heart rate, capillary refill, mental status, blood pressure) immediately after the bolus.
  • If signs of shock or severe dehydration persist, repeat the bolus of 20 mL/kg up to a total of 60 mL/kg (three boluses).
• Nursing Monitoring:
  • Strictly monitor for signs of fluid overload (e.g., development of pulmonary crackles, tachypnea, hepatomegaly, or a gallop heart rhythm).
  • Evaluate urinary output: target a minimum output of 1 to 2 mL/kg/hour in infants and 1 mL/kg/hour in older children.
  • Once the intravascular volume is restored and the child's mental status improves, transition them to ORT as tolerated.

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Pediatric Acute Respiratory Infections

Acute respiratory tract infections are another major focus of DOH child survival programs. Two common conditions frequently tested on the board are Bronchiolitis and Croup.

1. Bronchiolitis

• Causative Agent & Pathophysiology: Bronchiolitis is an acute inflammatory obstruction of the lower airway (bronchioles), most commonly caused by Respiratory Syncytial Virus (RSV). The virus invades the bronchiolar epithelial cells, causing cellular necrosis, mucosal edema, and mucus accumulation. This leads to airway narrowing, hyperinflation, air trapping, and patches of atelectasis.
• Clinical Presentation: Typically affects infants under two years of age (peaking at 2-6 months). Symptoms start with mild upper respiratory signs (rhinorrhea, low-grade fever) and progress to lower respiratory distress characterized by tachypnea, expiratory wheezing, crackles, nasal flaring, and intercostal/subcostal retractions.
• Nursing Interventions & Isolation:
  • Precautions: Implement Contact and Droplet Precautions. RSV is highly stable and can survive on surfaces and hands for hours, making meticulous hand hygiene and disinfection vital.
  • Oxygenation: Administer humidified oxygen (via nasal cannula, high-flow nasal cannula, or oxygen hood) to maintain SpO2 above 90% to 92%.
  • Hydration: Monitor hydration status closely. If the infant's respiratory rate is greater than 60 breaths/minute, oral feeding should be withheld (NPO status) to prevent aspiration. In these cases, hydration must be maintained via intravenous fluids or nasogastric tube feeding.
  • Nasal Suctioning: Perform gentle bulb or wall suctioning of the nasal passages before feedings and before sleep. Because infants are obligate nose breathers, nasal mucus obstruction significantly impairs their ability to feed and breathe.

2. Croup (Laryngotracheobronchitis)

• Causative Agent & Pathophysiology: Croup refers to a group of conditions characterized by inflammation of the larynx, trachea, and bronchi, most commonly caused by the Parainfluenza virus. The swelling of the subglottic mucosa leads to upper airway obstruction.
• Clinical Presentation: Characterized by a sudden onset, often at night, of a paroxysmal "barking" or "seal-like" cough, hoarseness, and inspiratory stridor. Mild to moderate cases show suprasternal retractions; severe cases can progress to respiratory failure.
• Nursing and Medical Management:
  • Keep the Child Calm: Agitation and crying significantly increase negative intrathoracic pressure, causing the floppy airway to collapse further and worsening the stridor. Encourage parents to hold the child.
  • Cool Mist Therapy: Exposure to cool mist (via a humidifier or by taking the child into a steam-filled bathroom or outside into cool night air) helps soothe the inflamed airway mucosa and liquefy secretions.
  • Nebulized Epinephrine (Racemic Epinephrine): Prescribed for moderate to severe stridor at rest. Epinephrine acts as a rapid-acting mucosal vasoconstrictor (alpha-1 agonist), which decreases subglottic edema. Nursing Alert: Monitor the child closely for at least 2 to 4 hours post-administration for a rebound effect (recurrence of severe airway obstruction once the medication wears off).
  • Corticosteroids: Administer a single dose of Dexamethasone (oral, IM, or IV) as prescribed to reduce airway edema. Its long half-life helps prevent recurrence of symptoms.