Human herpesviruses 6 and 7

Association of Viral Infections With Oral Cavity Lesions: Role of SARS-CoV-2 Infection

Different viral agents, such as herpesviruses, human papillomavirus, and Coxsackie virus, are responsible for primary oral lesions, while other viruses, such as human immunodeficiency virus, affect the oral cavity due to immune system weakness. Interestingly, it has been reported that coronavirus disease 2019 (COVID-19) patients can show cutaneous manifestations, including the oral cavity. However, the association between oral injuries and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still unclear. This narrative review aimed to summarize the available literature and provide an overview of oral lesions associated with COVID-19. An online literature search was conducted to select relevant studies published up to November 2020. The results of 17 studies showed variability in oral lesions associated with COVID-19, including ulcerations, aphthous-like lesions, and macules. The tongue, lips, and palate were the most frequent anatomical locations. According to current knowledge, the etiopathogenesis of multiple COVID-19-associated lesions seems to be multifactorial. The appearance of such lesions could be related to the direct or indirect action of SARS-CoV-2 over the oral mucosa cells, coinfections, immunity impairment, and adverse drug reactions. Nevertheless, COVID-19-associated oral lesions may be underreported, mainly due to lockdown periods and the lack of mandatory dispositive protection. Consequently, further research is necessary to determine the diagnostic and pathological significance of oral manifestations of COVID-19. All medical doctors, dentists, and dermatologists are encouraged to perform an accurate and thorough oral examination of all suspected and confirmed COVID-19 cases to recognize the disease's possible early manifestations.

Roseola infantum and its causal human herpesviruses

Roseola infantum, also known as exanthem subitum or sixth disease, is a generally benign febrile exanthem of infancy. It has a characteristic clinical course of high fever followed by the appearance of an exanthem upon defervescence. Febrile seizures are a frequent complication. Roseola is caused by infection with human herpesviruses 6 or 7 (HHV-6/7), which are acquired at a young age. Diagnosis is made by serology or by virus detection in body fluids and tissues. Treatment of roseola is supportive; recovery is usually complete with no significant sequelae. However, HHV-6/7 can reactivate in immunocompetent as well as immunocompromised individuals with severe systemic consequence.

Use of high-dose acyclovir in pityriasis rosea

BACKGROUND

The association of human herpesvirus 6 (HHV-6) and HHV-7 with pityriasis rosea suggests that systemic drugs directed against HHV may hasten recovery of patients with pityriasis rosea.

OBJECTIVE

The purpose of this study was to verify the efficacy of oral acyclovir in the treatment of pityriasis rosea.

METHODS

Eighty-seven consecutive patients were treated for 1 week with either oral acyclovir (800 mg 5 times daily) or placebo. In all patients, the time of lesion clearing and the number of new lesions appearing during treatment were recorded.

RESULTS

On the 14th day of treatment, 79% of treated patients fully regressed compared with 4% of the placebo group. The lesions cleared in 18.5 days in treated patients and in 37.9 days in the placebo group. Clearance was achieved in 17.2 days in patients treated in the first week from onset and in 19.7 days in the patients treated later. On the 7th day, there were significantly fewer new lesions in patients treated in the first week than in those treated later.

LIMITATIONS

This trial was neither randomized nor double blind. Objectivity was achieved by counting the lesions.

CONCLUSION

Acyclovir may be effective in the treatment of pityriasis rosea, especially in patients treated in the first week from onset, when replicative viral activity of HHV is probably very high.

Viruses in periodontal disease - a review

The purpose of this review was to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis. An involvement in periodontal diseases has been suspected specifically for human immunodeficiency virus (HIV) and herpes viruses. An association has been demonstrated between HIV infection and some distinct forms of periodontal infection, i.e. necrotizing lesions. Furthermore, reports of increased prevalence and severity of chronic periodontitis in HIV-positive subjects suggests that HIV infection predispose to chronic periodontitis. Several studies, most of them from the same research group, have demonstrated an association of herpesviruses with periodontal disease. Viral DNA have been detected in gingival tissue, gingival cervicular fluid (GCF) and subgingival plaque from periodontaly diseased sites. In addition markers of herpesviral activation have been demonstrated in the GCF from periodontal lesions. Active human cytomegalovirus (HCMV) replication in periodontal sites may suggest that HCMV re-activation triggers periodontal disease activity. Concerns regarding sampling, methods and interpretation cast doubts on the role of viruses as causes of periodontal disease.

The role of human herpes virus 6 and 7 in the pathogenesis of pityriasis rosea

Pityriasis rosea (PR) is an acute exanthematous inflammatory skin disease in which many epidemiological studies suggest a viral infection in its pathogenesis. Several viruses such as picornaviruses, parvoviruses and herpes viruses were accused as causative agents in PR. Human herpes virus-6 (HHV-6) and HHV-7 are newly discovered members of herpesviridae family. Several diseases including roseola infantum and PR have been linked with HHV-6 and HHV-7 in dermatology. We aimed to investigate the role of HHV-6 and HHV-7 in the pathogenesis of PR. Blood samples from 35 patients with acute PR and 30 healthy volunteers were examined to obtain titres for HHV-6 and HHV-7 antibodies. Anti-HHV-6 and -HHV-7 immunoglobulin (Ig) G antibodies were detected by IFA. The high titres of anti-HHV-6 IgG were determined in four patients and anti-HHV-7 IgG in only two of four patients. In our study, we haven't found any significant relationship between HHV-6, HHV-7 and PR. Our results were supported with the data of several previous studies.