Special Considerations in a Patient with Easy Bruising and Recurrent Shingles
This clinical presentation mandates immediate evaluation for underlying immunodeficiency or hematologic disorder, as recurrent herpes zoster is a red flag for compromised cellular immunity. 1, 2
Initial Diagnostic Workup
Hematologic Evaluation for Easy Bruising
If easy bruising or bleeding problems are present, obtain the following screening tests 1:
- Complete blood count (CBC) with platelet count to evaluate for thrombocytopenia 1
- Platelet function studies to assess for qualitative platelet defects 1
- von Willebrand screen to exclude von Willebrand disease 1
- Refer to hematology if any abnormalities are detected 1
Immunodeficiency Screening for Recurrent Shingles
Critical clinical clues indicating underlying immunodeficiency include: recurrent herpes zoster during a short period, disseminated herpes zoster, new lesions appearing more than a week after presentation, prolonged course despite antiviral medications, history of recurrent/invasive/prolonged infections by other pathogens, and family history of immunodeficiency or consanguinity 2.
Initial immunologic evaluation should include 1:
- Confirmation of normal newborn screening for profound T-cell immunodeficiency (if available) 2
- Complete blood count with differential to assess lymphocyte populations 1, 2
- Quantitative serum immunoglobulins (IgG, IgA, IgM) to evaluate humoral immunity 1, 2
- Lymphocyte subset analysis (CD4, CD8, NK cells) via flow cytometry to enumerate T-cell and NK cell populations 1, 2
- IgG antibodies to varicella-zoster virus to confirm prior exposure 2
- HIV testing as HIV infection is associated with T-cell immune defects predisposing to herpes zoster 1, 2
Additional Screening Based on Clinical Context
Consider screening for conditions that compromise cellular immunity 2:
- Diabetes mellitus (fasting glucose or HbA1c) 2
- Tuberculosis (if risk factors present) 2
- Malignancy screening (age-appropriate cancer screening, particularly hematologic malignancies) 2
- Nutritional assessment if malnutrition suspected 2
Management of Acute Herpes Zoster Episodes
Antiviral Therapy
For immunocompetent patients with uncomplicated herpes zoster: oral valacyclovir 1 gram three times daily or acyclovir 800 mg five times daily for 7-10 days, continuing until all lesions have completely scabbed 3, 4, 5.
For immunocompromised patients or disseminated disease: intravenous acyclovir 10 mg/kg every 8 hours is mandatory, continuing for at least 7-10 days until clinical resolution 3. Consider temporary reduction in immunosuppressive medications if applicable 3.
Monitoring During Treatment
- Renal function monitoring is essential during IV acyclovir therapy, with dose adjustments needed for renal impairment 3
- Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy 3
- If lesions fail to resolve within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 3
Prevention Strategies
Vaccination
The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 3. This is particularly important for patients with recurrent shingles to prevent future episodes 3.
Post-Exposure Prophylaxis
If the patient is exposed to active varicella-zoster infection and is immunocompromised 3:
- Varicella zoster immune globulin (VZIG) or intravenous immunoglobulin within 96 hours of exposure 3
- If immunoglobulin unavailable or >96 hours have passed, give 7-day course of oral acyclovir beginning 7-10 days after exposure 3
Common Pitfalls to Avoid
Do not dismiss recurrent shingles as simply "bad luck" - this pattern strongly suggests underlying immune dysfunction requiring investigation 2. Isolated, uncomplicated childhood or adult herpes zoster may not indicate immunodeficiency, but recurrent episodes are concerning 2.
Do not delay antiviral therapy while awaiting laboratory results - treatment is most effective when initiated within 48-72 hours of rash onset 3, 6.
Do not use topical antivirals as they are substantially less effective than systemic therapy 3.
Do not stop antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed - treatment should continue until clinical resolution 3.
Referral Criteria
Refer to hematology if: abnormal CBC, platelet dysfunction, or positive von Willebrand screen 1.
Refer to immunology/infectious disease if: recurrent herpes zoster, disseminated disease, abnormal lymphocyte subsets, hypogammaglobulinemia, or other concerning features suggesting primary immunodeficiency 1, 2.