Guidelines for Diagnosis and Prognosis of EBV‑Associated Cutaneous Proliferative Disorders

1. Diagnostic Workup

Perform a skin biopsy with comprehensive virological (EBER ISH, PCR) and immunophenotypic studies to determine whether the EBV‑infected cells are of T‑cell, NK‑cell, or B‑cell lineage, as this dictates prognosis and therapeutic planning. 1
Obtain adequate tissue for routine histopathology to evaluate the pattern and composition of the infiltrate (e.g., atypical lymphoid infiltrates, ulceration, necrosis). 1
Use in‑situ hybridization for EBV‑encoded RNAs (EBER) as the gold‑standard method for detecting EBV within tissue sections. 1
Apply double‑staining techniques that combine EBER detection with immunophenotypic markers (CD20/CD79a for B cells; CD3/CD4/CD8 for T cells; CD56 for NK cells) to definitively identify the infected cell population. 1
Perform immunohistochemistry for EBV latent proteins (EBNA, LMP‑1) to further characterize viral latency patterns. 1
Conduct PCR for EBV DNA on tissue sections, especially in regions where co‑infection with Borrelia is endemic. 6
Assess clonality by T‑cell receptor or immunoglobulin gene rearrangement studies to distinguish reactive from neoplastic proliferations. 1

Measure anti‑VCA IgG (≥ 1:640) and anti‑EA IgG (≥ 1:160); the combined pattern supports chronic active EBV infection. 3
Detect IgA antibodies to VCA and/or EA, which are frequently present in chronic active EBV. 4
Recognize that antibody titers vary between laboratories; interpretation should prioritize the overall pattern rather than absolute titers. 5
Perform quantitative PCR on peripheral blood mononuclear cells; viral loads >10²·⁵ copies/mg DNA (or ≥ 10,000 IU/mL in whole blood) are diagnostic for chronic active EBV. 1
Understand that healthy individuals may have occasional positive qualitative PCR results; quantitative assessment is essential to avoid false‑positive diagnoses. 4

Order a complete blood count with differential; cytopenias—particularly thrombocytopenia—signal a poorer prognosis. 3
Include a comprehensive metabolic panel with liver function tests to assess organ involvement. 1
Measure lactate dehydrogenase (LDH) levels as a marker of disease activity. 6
Perform serum protein electrophoresis to exclude an underlying monoclonal gammopathy. 6
Conduct HLA‑DR typing and peripheral blood marker analysis for additional immunogenetic information. 1
Document the classic triad of persistent/recurrent fever, lymphadenopathy, and hepatosplenomegaly, which characterizes systemic EBV disease. 3
Evaluate for specific cutaneous manifestations such as hypersensitivity to mosquito bites, hydroa vacciniforme‑like eruptions, or mucocutaneous ulcers. 1
Screen for systemic complications, notably hemophagocytic lymphohistiocytosis. 3
Obtain contrast‑enhanced CT of the chest, abdomen, and pelvis to rule out systemic lymphoma or nodal disease. 6
Consider PET/CT when available, recognizing that chronic wounds and reactive lymph nodes may produce nonspecific uptake. 8

Do not diagnose chronic active EBV solely on elevated antibody titers or a positive blood PCR; tissue confirmation of EBV and identification of the infected cell type are mandatory to differentiate benign reactive processes from potentially lethal T/NK‑cell lymphoproliferative disorders. 3
Infection of T‑cells or NK‑cells by EBV is associated with a significantly worse prognosis and a higher risk of progression to extranodal NK/T‑cell lymphoma or aggressive T‑cell lymphoproliferative disease, underscoring the importance of precise lineage identification. 1