Are viruses associated with aphthae and oral vesiculo-erosive disorders?

Herpes Simplex Virus Type 1 infection: overview on relevant clinico-pathological features

Herpes Simplex Virus Type 1 (HSV-1) is a nuclear replicating enveloped virus, usually acquired through direct contact with infected lesions or body fluids (typically saliva). The prevalence of HSV-1 infection increases progressively from childhood, the seroprevalence being inversely related to socioeconomic background. Primary HSV-1 infections in children are either asymptomatic or following an incubation period of about 1 week gives rise to mucocutaneous vesicular eruptions. Herpetic gingivostomatitis typically affects the tongue, lips, gingival, buccal mucosa and the hard and soft palate. Most primary oro-facial HSV infection is caused by HSV-1, infection by HSV-2 is increasingly common. Recurrent infections, which occur at variable intervals, typically give rise to vesiculo-ulcerative lesions at mucocutaneous junctions particularly the lips (herpes labialis). Recurrent HSV-1 infection within the mouth is uncommon in otherwise healthy patients, although in immunocompromised patients, recurrent infection can be more extensive and/or aggressive. The diagnosis of common herpetic infection can usually be based upon the clinical history and presenting features. Confirmatory laboratory diagnosis is, however, required when patients are, or may be, immunocompromised.

Bacterial diversity in aphthous ulcers

INTRODUCTION

Recurrent aphthous ulcers are common lesions of the oral mucosa of which the etiology is unknown. This study aimed to estimate the bacterial diversity in the lesions and in control mucosa in pooled samples using a culture-independent molecular approach.

METHODS

Samples were collected from ten healthy individuals and ten individuals with a clinical history of recurrent aphthous ulcers. After DNA extraction, the 16S ribosomal RNA bacterial gene was amplified by polymerase chain reaction with universal primers; amplicons were cloned, sequenced and matched to the GenBank database.

RESULTS

A total of 535 clones were analyzed, defining 95 bacterial species. We identified 62 putative novel phylotypes. In recurrent aphthous ulcer lesions 57 phylotypes were detected, of which 11 were known species. Control samples had 38 phylotypes, five of which were already known. Only three species or phylotypes were abundant and common to both groups (Gemella haemolysans, Streptococcus mitis strain 209 and Streptococcus pneumoniae R6). One genus was found only in recurrent aphthous ulcer samples (Prevotella) corresponding to 16% of all lesion-derived clones.

CONCLUSION

The microbiota found in recurrent aphthous ulcers and in the control groups diverged markedly and the rich variety of genera found can provide a new starting point for individual qualitative and quantitative analyses of bacteria associated with this oral condition.

Management strategies for HIV-associated aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is the most common oral mucosal disorder found in men and women of all ages, races, and geographic regions. There are three forms of the lesions (minor, major, and herpetiform), with major aphthous ulcers causing significant pain and potential for scarring. In HIV-infected individuals, these ulcers occur more frequently, last longer, and produce more painful symptoms than in immunocompetent persons. In addition, they may be associated with similar ulcerations involving the esophagus, rectum, anus, and genitals. The diagnosis of HIV-induced RAS requires a careful history of the condition, and a thorough extra- and intra-oral examination. Oral mucosal biopsies are required for non-healing ulcers in order to exclude the possibility of deep fungal infections, viral infections, and neoplasms. The cause of the ulcers in HIV-positive persons has not been elucidated--local diseases, genetic, immunologic, and infectious factors all probably play a role. The goals of current treatments are to promote ulcer healing, to reduce ulcer duration and pain while maintaining nutritional intake, and to prevent or diminish the frequency of recurrence. Initial therapy for infrequent RAS recurrences includes over-the-counter topical protective and analgesic products. Initial therapy for frequent RAS outbreaks requires topical anesthetics, binding agents, and corticosteroids. Major RAS and non-healing minor or herpetiform RAS may require intralesional corticosteroids and systemic prednisone. Second-line immunomodulators for frequent and non-healing ulcers includes thalidomide and other immunomodulators.

Examination of the oral mucosa and peripheral blood cells of patients with recurrent aphthous ulceration for human herpesvirus DNA

OBJECTIVE

The purpose of this study was to exam the oral mucosa and peripheral blood cells of patients with recurrent aph-thous ulceration (RAU) for the presence of the following human herpesviruses: herpes simplex viruses 1 and 2, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, human herpesvirus-6, and human herpesvirus-7.

STUDY DESIGN

Fifty-eight subjects with RAU and 10 control subjects were recruited at an academic referral center and enrolled in this prospective, nonrandomized, case-controlled study. Each of the subjects with RAU was seen during an acute episode, and swab specimens from lesional (RAU-acute/lesion) and clinically normal (RAU-acute/normal) oral mucosa were obtained. Each of 2 subjects with RAU was evaluated during more than one acute episode. Three subjects with RAU were seen between active episodes, and swab specimens were taken from clinically normal (RAU-convalescent) oral mucosa. Swab specimens from clinically normal (control/normal) oral mucosa were obtained from the control subjects. Peripheral blood specimens were obtained from subjects with RAU and control subjects at the time the swab specimens were performed. Through use of polymerase chain reaction, all swab and peripheral blood specimens were examined for the presence of human herpesvirus DNA. Statistical significance was determined by means of chi(2) analysis.

RESULTS

Herpes simplex virus and human herpesvirus-6 were found in a higher percentage of mucosal specimens from the control subjects (herpes simplex virus, 4/10; human herpesvirus-6, 5/9) than from the subjects with RAU (RAU-acute/lesion: 3/45 herpes simplex virus, 13/53 human herpesvirus-6; RAU-acute/normal: 7/48 herpes simplex virus, 9/53 human herpesvirus-6). No difference was demonstrated between RAU-acute/lesion, RAU-acute/normal, and RAU-convalescent mucosal specimens for any of the human herpesviruses. Different human herpesviruses were identified from individual subjects with RAU during subsequent episodes of disease. Epstein-Barr virus (6/35), human herpesvirus-6 (3/40), and human herpesvirus-7 (7/43) were detected in the peripheral blood mononuclear cells during acute RAU but not in RAU-convalescent or control peripheral blood mononuclear cells.

CONCLUSIONS

The detection of human herpesvirus DNA from the oral mucosa and peripheral blood mononuclear cells of patients with RAU appears to represent normal viral shedding rather than a direct causal mechanism in this disorder.

Recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is one of the most common oral mucosal disorders. Nevertheless, while the clinical characteristics of RAS are well-defined, the precise etiology and pathogenesis of RAS remain unclear. The present article provides a detailed review of the current knowledge of the etiology, pathogenesis, and management of RAS.