What is the recommended treatment for chickenpox in adults, particularly those with compromised immune systems or underlying conditions such as chronic lung disease or heart disease?

Treatment of Chickenpox in Adults

For immunocompetent adults with chickenpox, initiate oral acyclovir 800 mg five times daily for 7-10 days, starting within 24 hours of rash onset for maximum benefit. 1

Immunocompetent Adults

Standard Treatment Protocol

• Oral acyclovir 800 mg every 4 hours (5 times daily) for 7-10 days is the FDA-approved regimen for acute herpes zoster and is the standard treatment for adult chickenpox 1
• Treatment should be initiated within 24 hours of rash onset for optimal efficacy, though benefit may still occur if started within 72 hours 1, 2
• Acyclovir significantly reduces duration of acute infection, lesion healing time, pain duration, and new lesion formation 1

Adults with Chronic Conditions

For adults with chronic lung disease (COPD, emphysema, asthma) or chronic heart disease (excluding isolated hypertension), the same acyclovir regimen applies, but these patients require closer monitoring as they are at significantly higher risk for severe disease and complications including pneumonitis 3, 4, 5

Adults with diabetes mellitus also warrant the standard acyclovir treatment, as they have 1.4-5.9 times increased risk for invasive pneumococcal disease and complications 3

Immunocompromised Adults

Critical Management Differences

Immunocompromised patients require intravenous acyclovir, not oral therapy 1

This includes adults with:

• HIV infection with CD4 count considerations 3
• Hematologic malignancies (leukemia, lymphoma, Hodgkin disease, multiple myeloma) 3
• Solid organ transplant recipients 3
• Iatrogenic immunosuppression (long-term systemic corticosteroids, chemotherapy, radiation therapy) 3
• Congenital or acquired immunodeficiencies (B- or T-lymphocyte deficiency, complement deficiencies, phagocytic disorders) 3
• Functional or anatomic asplenia (including sickle cell disease) 3
• Chronic renal failure or nephrotic syndrome 3

Mortality Risk

Mortality in adults requiring intensive care for chickenpox is approximately 25%, with significantly higher risk in patients over 65 years old and those with immunocompromising conditions 4

Renal Dosing Adjustments

For patients with renal impairment receiving oral acyclovir 800 mg regimen 1:

• Creatinine clearance >25 mL/min: 800 mg every 4 hours (5 times daily)
• Creatinine clearance 10-25 mL/min: 800 mg every 8 hours
• Creatinine clearance 0-10 mL/min: 800 mg every 12 hours
• Hemodialysis patients: Administer additional dose after each dialysis session 1

Key Clinical Pitfalls

Age-Related Severity

Adults, particularly those over 65 years, experience significantly more severe disease than children, with higher rates of pneumonitis, ARDS, and mortality 4, 5, 6

Timing of Treatment

The critical window is within 24 hours of rash onset—treatment initiated later than 24 hours shows diminished efficacy, though some benefit persists if started within 72 hours 1, 2

Misclassification of Risk

Do not underestimate risk in adults with seemingly minor chronic conditions—even controlled asthma or diabetes increases pneumococcal disease risk substantially and warrants aggressive antiviral treatment 3

Pregnancy Considerations

Pregnant women face higher risk of fulminant disease and require specialist consultation, as varicella vaccine is contraindicated during pregnancy 3, 6

Prevention in High-Risk Adults

Adults with chronic lung disease, chronic heart disease, or immunocompromising conditions should receive pneumococcal vaccination (PCV20 alone or PCV15 followed by PPSV23 ≥1 year later) due to increased risk of secondary bacterial pneumonia 3

For adults with no evidence of varicella immunity, a 2-dose varicella vaccine series 4-8 weeks apart is recommended for prevention, except in those with severe immunocompromising conditions where the vaccine is contraindicated 3