Management of Chickenpox in Elderly Patients
Elderly patients with chickenpox should receive oral acyclovir 800 mg five times daily for 7-10 days, initiated within 24 hours of rash onset to reduce complications and accelerate healing. 1, 2
Immediate Antiviral Treatment
- Start oral acyclovir 800 mg five times daily (every 4 hours while awake) immediately upon diagnosis, ideally within 24 hours of rash onset 1, 2
- Treatment efficacy decreases significantly if initiated beyond 24 hours, though some benefit may still occur if started within 48-72 hours 1, 3
- Continue therapy for 7-10 days or until all lesions have completely crusted 2, 4
- Adults are at substantially higher risk than children for severe complications including pneumonia, hepatitis, encephalitis, and death 5, 6
When to Escalate to Intravenous Therapy
Switch to intravenous acyclovir 10 mg/kg every 8 hours if any of the following occur: 1, 2
- Signs of pneumonitis (dyspnea, cough, hypoxemia, chest pain)
- Neurological involvement (altered mental status, seizures, focal deficits)
- Hemorrhagic or disseminated rash
- Severe immunocompromise or inability to tolerate oral medications
- Failure to improve within 7-10 days of oral therapy
Renal Dose Adjustments
Elderly patients frequently have reduced renal function requiring dose modification: 2
- Creatinine clearance 25-50 mL/min: 800 mg every 8 hours (3 times daily)
- Creatinine clearance 10-25 mL/min: 800 mg every 8 hours
- Creatinine clearance <10 mL/min: 800 mg every 12 hours
- Monitor renal function during therapy, particularly in patients with baseline impairment 7
Critical Complications to Monitor
Examine daily for signs of bacterial superinfection, the most common complication requiring hospitalization: 8
- Expanding erythema around lesions with warmth and tenderness
- Purulent drainage from vesicles
- Increasing pain or systemic toxicity (fever, tachycardia, hypotension)
- Invasive group A streptococcal infection is the most frequent serious bacterial complication 8
Watch for viral complications: 8, 6
- Pneumonitis (most common serious viral complication in adults)
- Encephalitis or cerebellar ataxia
- Hepatitis
- Hemorrhagic complications (thrombocytopenia, disseminated intravascular coagulation)
Infection Control Measures
- Isolate the patient until all lesions have completely crusted over, typically 5-7 days 8, 1
- The patient remains contagious and can transmit varicella-zoster virus to susceptible contacts during this period 7
- Advise susceptible household contacts (particularly pregnant women without immunity, immunocompromised persons) to avoid contact 1
Post-Exposure Prophylaxis for Contacts
For susceptible high-risk contacts exposed to the patient: 1
- Administer varicella-zoster immune globulin (VZIG) within 96 hours of exposure to immunocompromised contacts, pregnant women without immunity, or neonates 8, 1
- If VZIG unavailable, consider oral acyclovir 10 mg/kg four times daily for 7 days starting 7-10 days after exposure 1
- Susceptible immunocompetent contacts may receive varicella vaccine within 3-5 days of exposure for possible disease prevention or modification 5, 8
Important Clinical Caveats
- Chickenpox is significantly more severe in adults than children, with higher rates of pneumonia, hospitalization, and death 5, 6
- Treatment does not eradicate latent virus or affect subsequent risk of herpes zoster 1, 2
- Most adults (85-95%) with negative or unknown history of chickenpox are actually immune; however, elderly patients from certain geographic regions (particularly tropical areas) may have higher susceptibility rates 5
- Acyclovir can be administered with or without food 2
Prevention for Future
- All adults aged 50 years and older should receive recombinant zoster vaccine (Shingrix) after recovery to prevent herpes zoster, administered as two doses 2-6 months apart 5, 7
- Natural chickenpox infection provides lifelong immunity to varicella but does not prevent later herpes zoster reactivation 8