Management of Post-Influenza Rash in Children
Most rashes occurring after flu in children are viral exanthemas from the influenza infection itself rather than drug reactions, and management focuses on supportive care with antipyretics and hydration while monitoring for signs of serious complications requiring hospitalization. 1, 2
Initial Assessment and Diagnosis
The key challenge is distinguishing between viral exanthema (from influenza itself) versus drug hypersensitivity in children who received medications during their illness:
- Influenza B specifically has been documented to cause morbilliform and other rash presentations in schoolchildren, though this association is infrequently described 2
- In the vast majority of cases, differentiation between virus-induced versus drug-induced rash during the acute phase is not possible clinically 1
- Approximately 10% of viral exanthemas are mistakenly perceived as drug allergies, most commonly implicating beta-lactams and NSAIDs 1
Home Management for Mild Cases
For children with rash but no concerning features:
- Administer antipyretics (acetaminophen or ibuprofen) to manage fever and discomfort 3, 4
- Never give aspirin due to Reye's syndrome risk 4
- Ensure adequate oral fluid intake to prevent dehydration 3, 4
- Monitor for development of warning signs requiring medical evaluation 5
Red Flags Requiring Immediate Medical Evaluation
Seek urgent medical attention if the child develops:
- Breathing difficulties, markedly raised respiratory rate, grunting, intercostal recession, or breathlessness 5
- Cyanosis 5
- Severe dehydration or inability to maintain oral intake 5
- Altered level of consciousness or drowsiness 5
- Prolonged or complicated seizures 5
- Signs of septicemia including extreme pallor, hypotension, or floppy infant 5
- Vomiting lasting 24 hours or more 5
- Severe earache 5
Hospital Management Criteria
Children meeting admission criteria require:
- Oxygen therapy to maintain saturation >92% via nasal cannula, head box, or face mask 5, 3
- Intravenous fluids at 80% basal levels if unable to maintain oral intake 5
- Antibiotic coverage for S. pneumoniae, S. aureus, and H. influenzae 5
Antiviral Therapy Considerations
Oseltamivir should be considered if the child has acute influenza-like illness with fever >38.5°C and has been symptomatic for ≤2 days 5:
- Dosing for children ≥12 months: weight-based (30-75 mg twice daily for 5 days) 5
- For severely ill hospitalized children, oseltamivir may be used if symptomatic <6 days, though evidence is limited 5
- Oseltamivir is NOT effective for parainfluenza viruses, which can present similarly 3
Diagnostic Testing in Hospital
For hospitalized children with rash and influenza:
- Full blood count with differential, urea, creatinine, electrolytes, liver enzymes, and blood culture 5
- Chest X-ray if hypoxic, severely ill, or deteriorating 5
- Pulse oximetry for all children being assessed for admission 5
- Molecular assay (RT-PCR) for influenza confirmation in hospitalized patients 5
- Nasopharyngeal aspirate or nose/throat swabs for viral identification 5
Discharge Criteria
Children can be safely discharged when:
- Clearly improving and physiologically stable 5
- Can tolerate oral feeds 5
- Respiratory rate <40/min (<50/min in infants) 5
- Awake oxygen saturation >92% in room air 5
Important Caveats
- Drug provocation testing is the gold standard for confirming drug hypersensitivity but is not preferred acutely 1
- Serological and PCR testing can identify concurrent viral infections, but this does not exclude drug hypersensitivity 1
- The presence of rash alone does not change influenza management unless accompanied by signs of anaphylaxis or severe systemic reaction 6
- Children with underlying neurological disorders, prematurity, sickle cell disease, immunosuppression, diabetes, or age <2 years are at higher risk for complications and warrant closer monitoring 7