Rapid detection and distinction of cutaneous herpesvirus infections by direct immunofluorescence

Microbiology laboratory and the management of mother-child varicella-zoster virus infection

Varicella-zoster virus, which is responsible for varicella (chickenpox) and herpes zoster (shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella (particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times: (1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection; (2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear (atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation; (3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and (4) when the baby is born and it is necessary to confirm a diagnosis of varicella (and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn.

The clinical spectrum and therapeutic challenge of eczema herpeticum

We present 5 cases of eczema herpeticum in patients with severe recalcitrant atopic dermatitis to illustrate the range of possible clinical findings and supporting laboratory data that can obscure the diagnosis and complicate treatment. Major issues include: the need for aggressive laboratory evaluation (molecular diagnostics, viral cultures, skin biopsy, serology); the possibility of recurrent or chronic infection; the value of empiric antiviral therapy; the possibility of infection with thymidine-kinase resistant strains; and the importance of achieving control over the dermatitis with nonmyelosuppressive immunomodulating agents such as intravenous immunoglobulin or interferon gamma for dermatitis that requires systemic treatment.

Comparison of the Tzanck test and polymerase chain reaction in the diagnosis of cutaneous herpes simplex and varicella zoster virus infections

BACKGROUND

Although the diagnosis of herpes simplex virus (HSV) and varicella zoster virus (VZV) infections is usually made clinically, the Tzanck test, electron microscopy, viral culture, polymerase chain reaction (PCR), and serologic tests can be utilized to verify the diagnosis.

METHODS

We conducted a study on a total of 98 patients (77 patients with recurrent herpes simplex and 21 patients with herpes zoster) to evaluate the reliability and reproducibility of the Tzanck test in comparison with PCR.

RESULTS

In herpes virus infections, the general positivity rates of the Tzanck test and PCR were 61.2% and 79.6%, respectively. The difference between the positivity rates of the two tests was statistically significant. The positivity rates of the tests differed according to the type and duration of the lesions.

CONCLUSIONS

Although PCR was superior to the Tzanck test, the Tzanck test has also been proven to be a reliable diagnostic method, with a sensitivity of 76.9% and a specificity of 100%. We recommend the use of this easy, quick, reproducible, and inexpensive diagnostic test more often in dermatologic practice, especially in cutaneous herpes virus infections.

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

Herpesviruses: emerging nosocomial pathogens?

BACKGROUND

Herpesviruses are ubiquitous pathogens that are known to cause infection in humans and animals. It is likely that more than 90% of adults have been infected by one or more herpesviruses. As hospitalized patients become increasingly immunosuppressed by virtue of illness or therapies, it is increasingly likely that human herpesvirus infection will become manifest in the hospital. Whether these manifestations represent manifestations of reactivated latent disease or true nosocomial infections is an open question.

METHODS

Review of the pertinent English-language literature.

RESULTS

There are eight known herpesviruses that cause disease in humans. Herpesviruses are double-stranded DNA viruses. The prototypical structure consists of an inner DNA core that is encased within a nucleocapsid that is icosahedral in configuration and consists of capsomere subunits. Herpesvirus infection generally occurs when virus is transmitted in oral secretions from an infected to a naive host. Clinical reactivation syndromes can occur in transplant patients, cancer chemotherapy patients, and patients with acquired immunodeficiency syndrome. Life-threatening infections are most closely associated with human herpesvirus-5 (cytomegalovirus), whereas the relationships between human herpesvirus-7 and clinical disease are largely undefined.

CONCLUSION

Clinical expressions of herpesvirus in surgical patients are not nosocomial infections, but are in the vast majority of cases the reactivation of latent infection. Reactivation disease can be lethal to the immunosuppressed host.

Viral diseases of the oral mucosa

A wide variety of both DNA and RNA viruses affect the oral cavity. When considered in conjunction with cutaneous features, careful examination of the oral mucosa and oropharynx aids the clinician in making a diagnosis. Examination of the oral cavity should be incorporated as a regular component of the dermatologic examination because diagnostic clues are readily available to assist in the evaluation of infectious processes.

Herpes zoster of the penis: an unusual location for a common eruption

Herpes zoster is an acute vesiculobullous eruption estimated to affect 10% to 20% of the population. The diagnosis usually can be based on clinical features alone, but laboratory studies may be needed for definitive diagnosis, particularly in atypical presentations.

Detection of herpes simplex virus DNA in serum and oral secretions during acute recurrent herpes labialis

Although herpes simplex virus (HSV) has been detected in the peripheral blood of immunocompromised patients and in neonates with disseminated disease, the extent to which the virus may be present in the blood during a localized infection in otherwise healthy patients is still unknown. Literature on patterns of HSV shedding into the oral cavity at the prodromal stage of the disease, during recurrences, and also during asymptomatic periods is still lacking. The present study aims at the detection of HSV DNA in the serum and oral secretions during acute herpes labialis using a highly sensitive technique, the polymerase chain reaction (PCR). The study included 10 patients with acute herpes labialis and five healthy controls. Using PCR, herpes simplex virus DNA was detected in the serum of seven patients (70%) and in the saliva of nine patients (90%). One of the control cases showed positive HSV DNA in the saliva (20%). There was good statistical agreement between the presence of HSV DNA in the serum and saliva. Frequency of attacks, patient's age, and gender had no statistically significant effect on the presence of the virus in serum or in saliva. It is concluded that HSV viremia during attacks of recurrent herpes simplex is more frequent than previously appreciated.

Evidence-based medicine in dermatology

EBM is the use of the best current evidence in making decisions about the care of individual patients. Practicing EBM requires five steps: (1) formulating well-built clinical questions, (2) finding the best evidence to answer the questions, (3) critically appraising the evidence, (4) applying the evidence to specific patients, and (5) saving the critically appraised evidence. The Cochrane Library is the best source for finding the best evidence about treatment. The second best method for finding evidence about treatment and the best source for finding most other types of best evidence in dermatology is by searching the MEDLINE database using the PubMed Clinical search engine of the National Library of Medicine (http://++www.ncbi.nlm.nih.gov/PubMed/clin ica l.html). MEDLINE searches have inherent software and operator limitations that make their reliability quite variable. The quality (strength) of evidence is based on a hierarchy of evidence: results of systematic reviews of well-designed clinical studies, results of one or more well-designed clinical studies, results of large case series, and expert opinion. Once the best evidence has been found, the EBM approach involves critically appraising the quality of the evidence, determining its magnitude and precision, and applying it to the specific patient. Guidelines to appraise critically and apply evidence are available. The clinical question, best evidence, and its critical appraisal should be saved in a format that can be easily retrieved for future use.

The clinical characteristics of intraoral herpes simplex virus infection in 52 immunocompetent patients

OBJECTIVE

Intraoral herpes simplex virus infection is commonly mistaken for recurrent aphthous stomatitis. The purpose of this study was to describe the clinical features of intraoral herpes simplex virus infection.

STUDY DESIGN

Fifty-two immunocompetent patients with culture-positive intraoral herpes simplex virus infection were studied.

RESULTS

The median age of the patients was 42 years. One third of the patients exhibited single ulcers; the remaining patients displayed multiple lesions. In 47 of 52 cases, the ulcers occurred on keratinized surfaces of the oral cavity; however, 5 patients had persistent ulcerations on nonkeratinized mucosa, a typical feature of herpetic ulcers in immunosuppressed patients. Of 27 patients with histories of recurrences, 22 were previously incorrectly diagnosed with recurrent aphthous stomatitis.

CONCLUSIONS

Herpes simplex virus infection of the oral cavity can usually be differentiated from other causes of recurrent oral ulcerations on the basis of its clinical appearance and distribution. The recognition of atypical features may prevent unnecessary and costly treatments for unrelated though clinically similar-appearing disorders.

What is new in clinical research of viral diseases of the skin

Viral diseases of the skin have become a much more serious problem with the increasing number of patients immunosuppressed by either AIDS or cancer chemotherapy. The emphasis in research on the diagnosis and treatment of these diseases is similar to that on the bacterial diseases several decades ago.

Herpes simplex: evolving concepts

A large body of molecular biologic research has begun to clarify some basic aspects of viral latency and reactivation. The clinical definition of herpes simplex virus infection is expanding, with the recognition that the disease is largely asymptomatic and that most transmission occurs during periods of asymptomatic viral shedding. With this awareness, serologic diagnosis has become increasingly important. New treatment modalities are now available, and other promising treatments are in development.