Can I issue a fit‑for‑work certificate to a patient with herpes zoster because she is not infectious?

Work Clearance for Herpes Zoster Patients

You can issue a fit-for-work certificate to an immunocompetent patient with localized herpes zoster if all lesions are completely dried and crusted, but not before—the statement that "she is not infectious" requires verification of complete lesion crusting, as patients remain contagious until this occurs. 1

Understanding Contagiousness Timeline

The critical issue is determining whether your patient is truly non-infectious:

• Herpes zoster remains contagious from 1-2 days before rash onset until all lesions have completely dried and crusted, typically 4-7 days after rash appearance 1, 2
• Transmission occurs primarily through direct contact with fluid from active vesicles, though airborne transmission is possible in healthcare settings 2
• Herpes zoster is approximately 20% as contagious as chickenpox, making it significantly less transmissible but still infectious until lesions crust 1, 2

Work Clearance Criteria

For General Workers (Non-Healthcare)

Complete work clearance without restrictions is appropriate when:

• All lesions have completely dried and crusted 1
• For non-crusting lesions (macules/papules), no new lesions have appeared within 24 hours 1, 3

However, even with clearance, the patient must avoid:

• Pregnant women, neonates, and immunocompromised individuals until all lesions are crusted 1, 2
• Swimming pools, gyms, and contact sports until complete crusting 1

For Healthcare Workers

The criteria are more stringent 4:

• Healthcare workers with localized herpes zoster may work if lesions are completely covered AND they avoid caring for high-risk patients (immunocompromised, pregnant women, neonates) until all lesions crust 4, 1
• Standard precautions with complete lesion coverage are mandatory 4
• Restriction from high-risk patient contact typically lasts 7-10 days after rash onset until complete crusting 1

Common Pitfalls to Avoid

Do not assume antiviral therapy makes the patient immediately non-contagious—viral shedding continues until lesions are fully crusted regardless of treatment 2. This is a critical error that could lead to premature work clearance.

Verify lesion status by direct examination:

• Inspect all lesions for complete crusting 1
• Assess for any new lesion formation 1
• Confirm no fluid-filled vesicles remain 2

Special Considerations

Immunocompromised Patients

If your patient is immunocompromised, exercise greater caution 4:

• New lesions may continue appearing for 7-14 days (versus 4-6 days in healthy hosts) 2
• Healing is slower, extending the contagious period 2
• Risk of disseminated infection is 10-20% without prompt antiviral therapy 2

Workplace Risk Assessment

Consider the patient's work environment 1:

• High-risk workplaces (healthcare, childcare, facilities with immunocompromised individuals): Stricter criteria apply
• Standard workplaces: Clearance once lesions are crusted with education about avoiding high-risk contacts
• Ability to keep lesions completely covered during work hours 4

Patient Education for Return to Work

Provide clear instructions 1:

• Use separate towels and pillows from household members
• Maintain meticulous hand hygiene
• Avoid direct contact with high-risk individuals until complete crusting
• Report any new lesion formation immediately

The key determination is objective verification that all lesions are completely dried and crusted—only then is the patient truly non-infectious and appropriate for unrestricted work clearance.