Treatment for a 16-Year-Old with Sore Throat, Fever, Cold, and Body Ache (2 Days)

Step 1 - Assess the Likely Cause

• Rhinovirus, adenovirus, influenza, EBV (mono), parainfluenza, coronavirus
• Suggested by the presence of cold/coryza + body aches (viral features)
• Most self-limited, resolving within 1 week

• Peak incidence in ages 5-15 years; still relevant at 16
• Abrupt onset of fever, sore throat, submandibular lymphadenopathy
• Absence of cough/coryza is more typical for GABHS

Key point: Coryza/cold symptoms here actually make viral etiology more likely. However, 16 years old is the right age for strep, so testing is warranted.

Step 2 - Clinical Decision Making: Use the Centor Criteria

• Score 0-1: GABHS unlikely. No testing, no antibiotics.
• Score 2+: Do a rapid antigen detection test (RADT). If positive - treat. If negative in adolescent - send throat culture.

Also consider infectious mononucleosis (EBV) - presents with fever, exudative pharyngitis, posterior cervical lymphadenopathy, malaise. Do a monospot test if suspected (note: can be falsely negative in first week).

Step 3 - Treatment

For Viral Pharyngitis (no confirmed GABHS) - Symptomatic Treatment:

Most viral pharyngitis resolves spontaneously within 3-7 days. Antibiotics are not indicated.

For Confirmed GABHS Pharyngitis (positive rapid test or culture):

Goals of antibiotic therapy: Shorten illness duration (by ~16 hours), prevent transmission, prevent suppurative complications (peritonsillar abscess, otitis media, sinusitis), and prevent rheumatic fever.

Treatment can safely be delayed up to 9 days after symptom onset and still prevent rheumatic fever - so waiting for culture results is appropriate if the rapid test is negative.

Step 4 - Special Concern: Infectious Mononucleosis (EBV)

• Do a Monospot test (note: may be negative in first week - has ~75% sensitivity at this age)
• Avoid amoxicillin/ampicillin - causes a classic florid maculopapular rash in mono patients
• If mono confirmed: avoid contact sports until splenomegaly resolves (risk of splenic rupture)
• Treatment is supportive (rest, analgesia, hydration)

Step 5 - Red Flags Requiring Urgent Evaluation

• Stridor, drooling, muffled voice, trismus - suggests deep space infection (peritonsillar abscess, epiglottitis)
• Toxic appearance, unable to swallow, high unremitting fever
• Neck stiffness (consider meningitis)
• Rash + fever (consider scarlet fever)

Summary Table

Cetirizine (Zyrtec) - When to Take It

Indications - When You Should Take It

Note: For the 16-year-old with cold symptoms and runny nose from the previous question - cetirizine can help with nasal symptoms only if allergic in origin. It does not treat viral infections directly.

Dosing Schedule

• Can be taken with or without food
• Best time: Evening/night is preferred by most - it lasts 24 hours and mild sedation is then less disruptive
• Onset: Within 1 hour; effects last 24 hours

When NOT to Take It (Cautions)

• Avoid if allergic to cetirizine or hydroxyzine
• Pregnancy: Category B (relatively safe, but consult a doctor)
• Avoid alcohol - can worsen sedation
• Driving/machinery: Though less sedating than older antihistamines, some people still feel drowsy
• Renal impairment: Dose reduction needed (renally cleared)
• Do not use for URI/cold in children under 2 years - FDA warns against this due to fatality reports

Side Effects to Know

• Headache
• Dry mouth
• Mild sedation/drowsiness
• GI upset (nausea, stomach discomfort)
• Pharyngitis
• Rare: aggressive reactions, convulsions

Unlike older antihistamines (e.g., diphenhydramine), cetirizine does not cause cardiac arrhythmias when combined with drugs like ketoconazole or erythromycin - making it safer in combination therapy.