Is human herpesvirus 7 the causative agent of pityriasis rosea?--A critical review

Overlapping Signs and Symptoms Between Recurrent Varicella and Pityriasis rosea Gibert

BACKGROUND

Pityriasis rosea Gibert (PRG) has features similar to those of common infectious childhood diseases, suggesting a viral cause, but no agent has been identified to date. We describe 4 children with PRG and 2 with recurrent varicella who were studied using photochronography, virology and immunology.

METHODS

The 6 patients with skin rashes visited our pediatric clinic from April 2012 to May 2016. Photographs of their skin lesions were taken; blood, skin lesions, and/or nasal lavage samples were collected to detect varicella-zoster virus (VZV) DNA and antibodies; and skin tests were carried out to measure cell-mediated immunity to VZV.

RESULTS

Herald patches were confirmed in 2 of 4 PRG patients. No specimen cultures were positive for infectious VZV. However, VZV-DNA was detected in skin lesions of 3 PRG patients. During the acute phase, 5 patients had IgG antibodies to VZV, and skin-test reactions were positive in 5 patients.

CONCLUSIONS

IgG antibody titers to VZV at rash onset were high, suggesting that they were already rising at the appearance of the rash and that reinfection with VZV must have occurred during the prodromal stage or several weeks before rash appearance in PRG patients whose immunity had declined below the threshold. Our study suggests a new pathogenesis of PRG that might help to address incongruities of past theories on PRG sites of viral entry and replication, incubation period and variations in the clinical course of PRG from prodrome to healing.

Atypical pityriasis rosea in a young Colombian woman. Case report

Introduction: Pityriasis rosea is an acute and self-limited exanthemfirst described by Gilbert in 1860. Its treatment is symptomatic, and although there is no conclusive evidence, it has been associated with the reactivation of the human herpesviruses 6 and 7 (HHV-6 and HHV-7). Case presentation: A 28-year-old woman, from Bogotá, Colombia, ahealth worker, attended the emergency room due to the onset ofsymptoms that began 20 days earlier with the appearance of punctiformlesions in the left arm that later spread to the thorax, abdomen, opposite arm, and thighs. The patient reported a history of bipolar II disorder and retinal detachment. After ruling out several infectious diseases, and due to the evolution of the symptoms, pityriasis rosea was suspected. Therefore, treatment was started with deflazacort 30mg for 21 days, obtaining a favorable outcome and improvement of symptoms after 2 months. At the time of writing this case report, the patient had not consulted for recurrence. Conclusion: Primary care physicians should have sufficient training indermatology to recognize and treat dermatological diseases since manyof them are diagnosed based on clinical findings. This is an atypicalcase, in which the patient did not present with some of the pathognomonic signs associated with pityriasis rosea.

Pityriasis Rosea, Gianotti-Crosti Syndrome, Asymmetric Periflexural Exanthem, Papular-Purpuric Gloves and Socks Syndrome, Eruptive Pseudoangiomatosis, and Eruptive Hypomelanosis: Do Their Epidemiological Data Substantiate Infectious Etiologies?

Many clinical and laboratory-based studies have been reported for skin rashes which may be due to viral infections, namely pityriasis rosea (PR), Gianotti-Crosti syndrome (GCS), asymmetric periflexural exanthem/unilateral laterothoracic exanthem (APE/ULE), papular-purpuric gloves and socks syndrome (PPGSS), and eruptive pseudo-angiomatosis (EP). Eruptive hypomelanosis (EH) is a newly discovered paraviral rash. Novel tools are now available to investigate the epidemiology of these rashes. To retrieve epidemiological data of these exanthema and analyze whether such substantiates or refutes infectious etiologies. We searched for articles published over the last 60 years and indexed by PubMed database. We then analyzed them for universality, demography, concurrent patients, temporal and spatial-temporal clustering, mini-epidemics, epidemics, and other clinical and geographical associations. Based on our criteria, we selected 55, 60, 29, 36, 20, and 4 articles for PR, GCS, APE/ULE, PPGSS, EP, and EH respectively. Universality or multiple-continental reports are found for all exanthema except EH. The ages of patients are compatible with infectious causes for PR, GCS, APE/ULE, and EH. Concurrent patients are reported for all. Significant patient clustering is demonstrated for PR and GCS. Mini-epidemics and epidemics have been reported for GCS, EP, and EH. The current epidemiological data supports, to a moderate extent, that PR, GCS, and APE could be caused by infectious agents. Support for PPGSS is marginal. Epidemiological evidences for infectious origins for EP and EH are inadequate. There might be growing epidemiological evidence to substantiate or to refute our findings in the future.

Virome genomics: a tool for defining the human virome

High throughput, deep sequencing assays are powerful tools for gaining insights into virus-host interactions. Sequencing assays can discover novel viruses and describe the genomes of novel and known viruses. Genomic information can predict viral proteins that can be characterized, describe important genes in the host that control infections, and evaluate gene expression of viruses and hosts during infection. Sequencing can also describe variation and evolution of viruses during replication and transmission. This review recounts some of the major advances in the studies of virus-host interactions from the last two years, and discusses the uses of sequencing technologies relating to these studies.

Study of role of streptococcal throat infection in pityriasis rosea

Background:

Pityriasis rosea is a common, acute exanthem of uncertain etiology. The exact cause of pityriasis rosea is not known but various hypotheses have been postulated incriminating infective agents such as viruses, bacteria, spirochete and noninfective etiologies such as atopy and autoimmune causes have also been investigated.

Aim:

We undertook a study to investigate the role of Streptococcus haemolyticus in the causation of pityriasis rosea and study the levels of C-reactive protein (CRP) and ASLO titer in patients with pityriasis rosea.

Materials and Methods:

The study included 20 patients with pityriasis rosea attending the outpatient dermatology department at JIPMER hospital during the period from June to December 2004. Corresponding number of age- and sex-matched controls were chosen from amongst healthy individuals and patients attending skin OPD with dermatological disorders other than pityriasis rosea.

Results:

On analyzing the data collected from 20 cases of pityriasis rosea, the average age was found to be 15.3 years and ranged from 5 years to 30 years. The male to female ratio was found to be 1.5:1. The average duration of illness was 14.5 days (median) and 29.3 days (mean). CRP was negative in all the cases as well as the controls. ASLO titer was found to be raised in 2 (10%) cases, while it remained below the critical value in all the controls. On comparing the cases and controls, the raised ASLO titer in the cases was found to be not statistically significant (p = 0.147). From the throat swab culture, Streptococcus haemolyticus was isolated from only one case and none of the controls. This finding was not statistically significant (p = 0.310).

Conclusion:

As per the findings of the present study, we arrived at conclusion that there is no association between streptococcus pharyngitis and pityriasis rosea.

Phenotypical characteristics of the immune cells in allergic contact dermatitis, atopic dermatitis and pityriasis rosea

Allergic contact dermatitis (ACD) is a cell-mediated, delayed type IV immunologic reaction. Atopic dermatitis (AD) is a chronic inflammatory skin disease that results from a complex interaction between immunologic, genetic, and environmental factors. Pityriasis rosea (PR) is a self-limited eruption of unknown etiology. Immune cell infiltrate is a constant feature in the inflammatory skin diseases. Here, we performed phenotypical characterization of the immune cells in ACD, AD and PR (ten cases each). We performed immunohistochemical stains for B cells (CD20), T cells (CD3), histiocytes (CD68) and T cells with cytotoxic activity (granzyme-B). The data were compared with findings in 20 specimens of normal skin. The results were scored as mean values of positively stained immune cells. Immunohistochemistry showed significantly high counts of immune cells in lesional skin (ACD, AD and PR) compared to the normal one (p < 0.05). In the lesional skin, the immune cells were composed predominantly of CD3(+) T lymphocytes and CD68(+) cells (histiocytes). Some of the CD3(+) cells were granzyme B(+). The counts of some immune cells (CD3(+) and CD68(+)) were high in ACD compared to AD and PR. The counts of CD20(+) and granzyme B(+) cells were high in PR compared to ACD and AD. However, these differences did not reach the level of statistical significance. The present data describe the profile of the immune cell infiltrate in AD, ACD and PR. The cell-mediated immunity seems to have critical role in the development of these lesions.

The role of human herpesvirus 6, human herpesvirus 7, Epstein-Barr virus and cytomegalovirus in the aetiology of pityriasis rosea

AIM

To identify the role of human herpesvirus 6 (HHV-6), HHV-7, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in the pathogenesis of pityriasis rosea (PR).

MATERIAL

Polymerase chain reaction with specific primers for HHV-6 and HHV-7 DNA sequences was performed on the blood and tissue samples of 25 patients with PR and on the blood samples of age- and sex-matched healthy controls. HHV-6, EBV, CMV immunoglobulin M (IgM) and IgG were analysed by enzyme-linked immunosorbent assay, HHV-7 IgM and IgG were analysed by indirect immunofluorescence on the serum samples of the study population. In the patient group, the values were studied 2 weeks later again (second control).

RESULTS

There were no differences between the first and second controls of the patients and healthy subjects regarding HHV-6 IgM, HHV-7 IgM, CMV IgM, EBV IgM results. There were significant differences between the first [HHV-6 DNA (2 of 25), HHV-7 DNA (6 of 25)] and second control [HHV-6 DNA (1 of 25), HHV-7 DNA (11 of 25)] of the patients for the blood samples in favour of HHV-7. PR patients showed higher amounts of HHV-6 and HHV-7 DNA positivity when compared with that of healthy subjects. HHV-7 seemed to be more important regarding tissue samples [HHV-6 DNA (7 of 25), HHV-7 DNA (12 of 25) first control, HHV-6 DNA (6 of 25), HHV-7 DNA (12 of 25) second control] as well as blood samples.

CONCLUSION

Though our results failed to support a causal relationship among EBV, CMV and PR, they indicated a possible role for HHV-6 and especially HHV-7 in a group of Turkish patients but other aetiological factors may exist.

The detection of human herpesvirus-8 DNA in plasma and peripheral blood mononuclear cells in adult patients with pityriasis rosea by polymerase chain reaction

BACKGROUND

Herpesvirus-like particles have been reported to be detectable by electron microscopy in lesional biopsy of patients with pityriasis rosea (PR). We report a study investigating the association of PR with human herpesvirus-8 (HHV-8) infection.

METHODS

Our setting is a teaching clinic affiliated to a university. We recruited eight patients aged 28-47 years (mean: 34.5 years) diagnosed with PR during a one-year period. We collected acute blood specimens at presentation and convalescent blood specimens three to four weeks later. We also collected skin scrapings from the herald patch where present and from truncal secondary lesions.

RESULTS

We detected HHV-8 DNA by a nested PCR (polymerase chain reaction) targeting, respectively, a 233-bp and a 160-bp fragment of ORF 26. PCR for HHV-8 DNA was negative in the peripheral blood mononuclear cells and plasma of acute and convalescent specimens of all patients, and negative in all skin scrapings. We detected anti-HHV-8 IgG and IgM antibodies by the indirect immunofluorescence. Four patients had IgG antibodies against HHV-8, but with no significant rise of titre. None were positive for anti-HHV-8 IgM antibody.

CONCLUSION

We conclude that PR is not associated with HHV-8 infection.

Lichen planus is associated with human herpesvirus type 7 replication and infiltration of plasmacytoid dendritic cells

BACKGROUND

Lichen planus (LP) is a common inflammatory skin disease of unknown aetiology. Viral causes have been suggested.

OBJECTIVES

To find candidate viruses associated with LP.

METHODS

Lesional and nonlesional skin samples, peripheral blood mononuclear cells and serum were obtained from patients with LP. Ultrastructural, viral DNA, immunohistochemical and serological analyses were performed, and comparisons were made with psoriatic and normal skin.

RESULTS

Electron microscopy revealed typical 120-200-nm enveloped particles with a 100-nm nucleus resembling human herpesvirus (HHV) virions both in dermis and in epidermis of lesional LP tissue. HHV-7 DNA was found in 11 of 18 lesional LP samples, as opposed to only one of 11 nonlesional LP samples (P =0.06), two of 11 lesional psoriasis samples (P = 0.05) and none of four normal skin samples. No relation was found between LP skin and DNA of other known HHVs (HHV-1-6 and 8). With immunohistochemistry, significantly more HHV-7+ cells were found in lesional LP epidermis than in normal epidermis. Lesional LP dermis contained significantly more HHV-7+ cells than nonlesional LP, psoriatic or normal dermis. Moreover, LP skin contained overwhelmingly and consistently more plasmacytoid dendritic cells (upregulated in virally induced conditions) than nonlesional LP samples.

CONCLUSIONS

We conclude that HHV-7 replicates in LP lesions, but not in psoriasis, another inflammatory skin condition. HHV-7 is possibly involved in the pathogenesis of LP. These preliminary data make further research on this topic of interest.