Antibiotic Management, Prevention, and Care of Pertussis in Children

First‑Line Antibiotic Therapy

Azithromycin is recommended as the first‑line macrolide for all children with suspected pertussis, using age‑adjusted dosing (10 mg/kg on day 1, then 5 mg/kg daily for days 2‑5 in children ≥ 6 months; 10 mg/kg daily for 5 days in infants < 6 months). – Centers for Disease Control and Prevention (CDC) [MMWR] [@1]
In infants younger than 1 month, azithromycin is preferred over erythromycin because it carries a markedly lower risk of infantile hypertrophic pyloric stenosis (IHPS). – CDC [@1]
For infants 1–5 months, azithromycin or clarithromycin may be used as first‑line agents, based on demonstrated in‑vitro activity, safety profile, and convenient dosing schedules. – CDC [@1]
Children ≥ 6 months and adults receive azithromycin 500 mg on day 1 followed by 250 mg daily on days 2‑5; pediatric dosing follows the regimen above. – CDC [@1]
When macrolides are contraindicated, trimethoprim‑sulfamethoxazole (TMP‑SMZ) is an acceptable alternative for patients older than 2 months. – CDC [@1]

Antibiotics should be started immediately on clinical suspicion, without awaiting culture results; treatment during the catarrhal phase (first ≈ 2 weeks) clears B. pertussis from the nasopharynx, reduces coughing paroxysms by ~50 % and lowers complication rates. – Praxis [@3]
If therapy is begun after ≈ 3 weeks of cough (paroxysmal phase), symptom improvement is modest, but treatment remains essential to prevent onward transmission because 80‑90 % of untreated patients naturally clear the organism within 3‑4 weeks. – Praxis [@2]
Macrolide therapy eradicates B. pertussis from the nasopharynx irrespective of when treatment is initiated, supporting its use for infection control even in late disease. – Praxis [@3]

β‑agonists, antihistamines, systemic corticosteroids, and pertussis‑specific immunoglobulin have not shown benefit in reducing cough episodes or improving outcomes and should not be used. – Praxis [@3]

Clinicians should watch for weight loss, sleep disturbance, post‑tussive vomiting, and pressure‑related injuries (e.g., pneumothorax, epistaxis, subconjunctival hemorrhage, rib fracture). – Praxis [@3]
Infectious complications such as primary/secondary bacterial pneumonia and otitis media, as well as serious neurological events (seizures, hypoxic encephalopathy), require prompt evaluation. – Praxis [@3]

Infants < 12 months—particularly those < 4 months—have the highest risk of severe or fatal outcomes (apnea, pneumonia, seizures, death) and should be strongly considered for admission. – Praxis [@4]
Infants < 1 month receiving macrolides must be monitored for IHPS and other serious adverse events. – CDC [@1]
Older children and adolescents have a markedly lower risk of severe disease (≈ 1‑2 % hospitalization rate) but remain important sources of transmission. – Praxis [@3]

Household isolation should continue for 5 days after the start of antibiotics; secondary attack rates exceed 80 % among susceptible contacts, underscoring the need for prompt isolation. – Praxis [@3]
If antibiotics cannot be administered, isolation must be maintained for 21 days from cough onset. – Praxis [@3]
In health‑care facilities, confirmed pertussis patients should be placed in private rooms or cohorted with other pertussis cases after the first 5 days of antimicrobial therapy. – CDC [@5]
Health‑care workers should wear a surgical mask when within 3 feet of a confirmed or suspected pertussis patient, in addition to standard precautions. – CDC [@5]

All household and close contacts should receive macrolide prophylaxis within 21 days of exposure, regardless of age or vaccination status, using the same dosing regimens as for treatment. – CDC [@1]
Priority groups for PEP include: all household members, infants < 12 months (especially < 4 months), pregnant women in the third trimester, and health‑care workers with known exposure. – CDC [@1]
The goal of prophylaxis is eradication of B. pertussis from the nasopharynx of both symptomatic and asymptomatic carriers to prevent secondary transmission. – Praxis [@4]
Asymptomatic contacts who receive prophylaxis may continue normal activities; routine laboratory testing is not required—clinical monitoring suffices. – Praxis [@4]

Pertussis vaccination does not provide lifelong immunity; protection wanes after 5‑10 years, allowing breakthrough infections. – Praxis [@3]
Routine DTaP vaccination should be maintained for siblings and other household contacts who are not up‑to‑date, because immunity diminishes over time and neither vaccination nor natural infection confers permanent protection. – Praxis [@3]
No additional pertussis vaccine doses are recommended for children with a documented pertussis episode (culture‑positive or epidemiologically linked). – CDC [@5]
Children with confirmed pertussis should complete their remaining series with DT vaccine to ensure diphtheria and tetanus protection. – Praxis [@3]

Obtain a nasopharyngeal aspirate or Dacron swab for culture and/or PCR; culture remains the only definitive diagnostic method. – Praxis [@2]
Suspect pertussis in any child with a cough lasting ≥ 2 weeks accompanied by paroxysms, post‑tussive vomiting, or inspiratory “whoop,” even if fully vaccinated. – Praxis [@3]
Perform diagnostic testing promptly in hospitalized patients to enable the earliest possible de‑escalation of infection‑control precautions. – CDC [@5]

Do not rule out pertussis solely on the basis of vaccination status; breakthrough cases can present atypically and may lack the classic “whoop.” – Praxis [@3]
Avoid delaying testing or treatment while awaiting classic symptoms; early intervention can cut transmission and may shorten the disease course by ~50 %. – Praxis [@3]
CDC recommends azithromycin for infants < 6 months despite the lack of FDA licensure for this age group, because the benefit of preventing severe disease outweighs potential medication risks. – Praxis [@2]
Erythromycin should be avoided in infants < 6 months due to its strong association with IHPS; azithromycin presents a substantially lower risk. – CDC [@1]
Antibiotic prophylaxis provides only short‑term protection; sustained prevention relies on maintaining up‑to‑date vaccination. – Praxis [@4]