Dermatology Online Journal

Unilateral laterothoracic exanthem with coincident evidence of Epstein-Barr virus reactivation: Exploration of a possible link
Vijay Zawar MD¹, Antonio Chuh MD²
Dermatology Online Journal 14 (1): 24

1. Department of Dermatology, NDMVPS Medical College, Nashik, India
2. Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong. achuh@iohk.com

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We read with admiration the paper by Scheinfeld on possible endogenous reactivation of Epstein-Barr virus (EBV) in a 35-year-old woman with clinical diagnosis of unilateral laterothoracic exanthem (ULE) [1]. We reported the first few cases of ULE and its variants in Asia [2, 3, 4, 5]. We entirely agree that ULE is the most appropriate diagnostic label for the patient concerned.

We cast doubts, however, on the methodology of the virological investigations. The EBV early antigen ELISA value dropped from 81.9 to 2.1 (reference: 0.0-19.9) 4 weeks apart. The IgM and IgG against EBV viral capsid antigen saw no change in both specimens (IgM at 2.8 and 2.8, reference: 0.0-19.9; IgG at >20 and >20, reference: 0.0-19.9). Antibodies against EBV nuclear antigen dropped from 87.0 to 2.1 (reference: 0.0-19.9). The author admitted that polymerase chain reaction was not performed to detect viral DNA in plasma or peripheral blood mononuclear cells, and that a skin disease concomitantly occurring with viral reactivation does not necessarily imply the latter being the aetiology of the former. However, there was no mention in this case report that the serological investigations were performed in parallel.

We agree that DNA-sequence-based methods are not absolutely necessary to document reactivation of herpesviruses. We have previously reported a case-control study for the detection of cytomegalovirus, EBV and parvovirus B19 DNA in plasma of patients with pityriasis rosea [6]. From our experience, documenting endogenous viral reactivation with full facilities for polymerase chain reaction and serologies is a difficult-enough task, not to say detecting such with serology alone. We have also highlighted the limitations of establishing antibody avidities to differentiate primary infection and endogenous reactivation of viruses [7]. However, even such was not attempted in this case report.

Depending on serology alone to substantiate reactivation of herpesvirus can be acceptable if they investigators have limited resources. However, whether the antibody titres were assessed in parallel should be explicitly stated. It is well known that serological results for EBV have low rest-retest reliability, in-between different laboratories but also within the same laboratory [8, 9]. Such is related to many factors including an element of subjectivity for the investigators to judge the level of fluorescence in indirect immunofluorescence tests [8].

We thus write in alerting the readers of this journal the importance of proper conduction and interpretation of serological and other laboratory results in validly substantiating reactivation of EBV or other herpesviruses.

References

1. Scheinfeld N. Unilateral laterothoracic exanthema with coincident evidence of Epstein Barr virus reactivation: Exploration of a possible link. Dermatol Online J. 2007; 13(3): 13.

2. Zawar V. Asymmetric periflexural exanthema: a report in an adult patient. Indian J Dermatol Venereol Leprol. 2003 Nov-Dec;69(6):401-4. PubMed

3. Chan PKS, To KF, Zawar V, Lee A, Chuh AAT. Asymmetric periflexural exanthem in an adult. Clin Exp Dermatol 2004 May;29(3):320-1. PubMed

4. Chuh AAT. Asymmetric periflexural exanthem - report of the first patient in Asia and its novel variants. 2nd Chinese/Anglo Dermatology Congress, and National Academic Conference of Dermatology and Venereology. November 2004, Guangzhou, China.

5. Chuh AAT, Chan HHL. Unilateral mediothoracic exanthem - a variant of unilateral laterothoracic exanthem - original description of two patients. Cutis 2006 Jan;77(1):29-32. PubMed

6. Chuh AAT. The association of pityriasis rosea with cytomegalovirus, Epstein-Barr virus and parvovirus B19 infections - a prospective case control study by polymerase chain reaction and serology. Eur J Dermatol 2003 Jan-Feb;13(1):25-8. PubMed

7. Chuh AAT, Kempf W. The identification of primary human herpesvirus 7 infection in young adults with pityriasis rosea by investigating avidity of antibodies. J Eur Acad Dermatol Venereol 2006 May;20(5):629-30. PubMed

8. Centers for Disease Control and Prevention. Epstein-Barr virus and infectious mononucleosis. National Center for Infectious Diseases. Available at: www.cdc.gov/ncidod/diseases/ebv.htm. Accessed on 13 November 2007.

9. Centers for Disease Control and Prevention. Chronic fatigue possibly related to Epstein-Barr virus - Nevada. MMWR Morb Mortal Wkly Rep 1986 May:35(21);350-2. PubMed

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