Infection Viral

Adenovirus. Adenovirus is the most common cause of viral pharyngitis. It is a double-stranded DNA virus. Serotypes 3,4, and 7 are frequently associated with viral pharyngitis. It is transmitted by either respiratory droplets or direct contact. School-aged children are most commonly affected. The classic presentation includes fever, sore throat, coryza, and red eyes. Adenovirus is cytolytic to the epithelial cells it invades and induces a localized inflammatory response in the surrounding tissues. Nasopharyngeal swabs can be obtained for viral cultures and a negative monospot test should be confirmed. It is usually self-limiting and lasts five to seven days. Treatment is supportive. Severe morbidity and mortality are rare and only seen in patients with altered immune function. Complications of adenovirus infection include keratoconjunctivitis (pink eye), acute hemorrhagic cystitis/nephritis, and gastroenteritis. Ribavirin has been advocated in several case reports when systemic infection occurs.

Upper Respiratory Viruses. Pharyngitis is a frequent component of the common cold. It may be caused by several upper respiratory viruses. Rhinovirus is the most common pathogen. Others viruses include parainfluenza virus, influenza virus, and coronavirus. The common cold will occur in any age group but extremes of age, immunosuppressed, and immunocompromised persons are most susceptible. The average healthy adult experiences cold-like symptoms at least twice a year. Transmission of viral particles occurs by inhaling respiratory particles or from direct contact. Signs and symptoms of viral pharyngitis are similar to those of bacterial pharyngitis. The incidence of laryngeal involvement is more common with viral infection when compared with bacterial infection and may help distinguish between the two etiologies. Other upper respiratory complaints include rhinorrhea, postnasal drip, nasal congestion, hoarseness, and cough. When associated with the influenza virus, gastrointestinal (GI) complaints such as stomach cramping and diarrhea are common.

Specific identification of the offending viral pathogen is not necessary, because symptoms are usually self-limiting and last approximately one week. There is no cure for the common cold or the flu, so treatment is targeted at symptom palliation. Some studies have demonstrated that zinc and vitamin C may decrease the length of viral-associated symptoms. Amantadine may decrease the duration of symptoms resulting from influenza virus infection when taken early in the prodromal stage.

Epstein-Barr Virus. Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is a double-stranded DNA virus in the herpesvirus family. It is transmitted by direct contact or by aerosolized viral particles. The virus infects B lymphocytes, and symptom manifestation consists of the triad of fever, lymphadenopathy, and pharyngitis. A white exudate on the tonsils is characteristic of EBV infection, and a skin rash may occur in patients treated with antibiotics, especially amoxicillin. Other symptoms include hepatosplenomegaly, hepatomegaly, encephalitis, pericarditis, and autoimmune hemolytic anemia. In rare cases, patients may present to an otolaryngologist with airway obstruction or cranial nerve palsies.

Diagnosis is made by the presence of heterophil antibodies detected on a monospot test. IgM antibodies to EBV viral capsid antigens can be screened if monospot tests are negative. Treatment for EPV is supportive, and symptoms may last for weeks to months. Splenomegaly is present in approximately 50% of infected patients and hepatomegaly is present in an additional 10% to 20%. Infected persons should be counseled to avoid contact sports for two to four months because of the risk of solid organ injury or rupture. In severe cases of mononucleosis, glucocorticoids may be used to diminish tonsillar hypertrophy and lymphadenopathy that may compromise the airway.

EBV is discussed in further detail in Chapter 10.

Cytomegalovirus. Cytomegalovirus (CMV) is a double-stranded DNA virus in the herpesvirus family. CMV presents similarly to EBV and patients are commonly misdiagnosed with mononucleosis when acutely infected. CMV is transmitted by direct contact of mucosal surfaces, blood transfusion or organ transplant, maternal breast milk consumption, and rarely by aerosolized viral particles. Symptoms predominantly include fever, lymphadenopathy, and less commonly pharyngitis. Ulceration of the pharynx or esophagus may be present in severe cases, especially in immunocompromised patients with human immunodeficiency virus (HIV). CMV infection during pregnancy may result in fetal hearing loss, visual impairment, and diminished mental and/or motor capabilities.

Diagnosis is made by a rise in CMV antibody titers and a negative monospot test. Enzyme-linked immunosorbent assay (ELISA) antibody tests for CMV IgM antibodies are also available. Treatment is typically supportive because most cases are self-limiting. Ganciclovir has excellent activity against CMV and may be required in cases of severe infections, debilitated patients, and immunosuppressed or immunocompromised persons. Acyclovir, valacyclovir, famciclovir, cidofovir, and foscarnet may also be used.

Coxsackie Virus. Coxsackie viruses are members of the enterovirus genus and are further divided into coxsackie A viruses and coxsackie B viruses. Coxsackie A viruses are important pathogens in the head and neck because they cause herpangina and hand-foot-and-mouth disease. There are 24 serotypes of coxsackie A viruses. Coxsackie viruses are spread by direct contact or fecal oral contamination. Diagnosis is made clinically although serological tests are available. ELISA IgM assays, cell cultures, and polymerase chain reaction (PCR) tests are all available.

Herpanginais caused by coxsackie A serotypes 2, 3,4,5,6, 8, and 10. It is characterized by the presence of gray-white papulovesicles found on the structures of the oropharynx. These papulovesicles are surrounded by erythematous halos and progress to become ulcerative lesions. Lesions are usually present for five to seven days and resolve spontaneously. Hand-foot-and-mouth disease is most frequently caused by serotype 16. Patients present with ulcerated vesicles surrounded by erythematous halos. Oral lesions are usually the first to appear and are most commonly found on the tongue, palatal, buccal, and gingival mucosa. The oropharynx is rarely affected. Skin lesions appear one to two days after the oral lesions are present. They form as a maculopapular lesion surrounded by a red halo and are more common on the hands than the feet. Lesions usually resolve spontaneously in 5 to 10 days.

Oral lesions are often painful and may require symptomatic relief. Viscous lidocaine mouth rinses or mouthwashes containing combinations of bismuth, benadryl, carafate, or steroids may palliate localized symptoms. Acyclovir may reduce the duration of symptoms when prescribed during initial presentation.

Herpes Simplex Virus. Herpes simplex virus (HSV) is a DNA virus with two distinct subtypes: HSV-1 and HSV-2. Classically, HSV-1 occurs more frequently in the head and neck regions and HSV-2 occurs more commonly in the genitourinary regions, but either virus may be detected in either location. The virus is transmitted by direct contact with infected mucus or saliva. Gingivostomatitis and pharyngitis are the most common head and neck symptoms of acute infection and may be accompanied by nonspecific complaints of fever, malaise, myalgia, and lymphadenopathy. Vesicular lesions on an erythematous base are the classic finding on physical exam. These most frequently are present at the vermillion borders and may be triggered by ultraviolet light exposure, hormonal changes, or stress. These lesions are often termed "cold sores." Lesions are less commonly present on the buccal mucosa, tonsils, and pharyngeal walls. The acute infection lasts 7 to 10 days and both lesions and symptoms resolve spontaneously. The virus is then thought to lie dormant in the dorsal root ganglion, and periodic reactivation of the virus results in recurrent infections.

Historically, diagnosis can be made by taking a vesicular scraping and performing a Tzanck smear, which is accurate in approximately 60% to 75% of infected patients. Viral cultures can also be grown and take approximately 48 hours for adequate inoculation and incubation. More recently, PCR techniques have replaced older techniques for rapid detection and viral subtyping. Antivirals such as acyclovir, valacyclovir, and famciclovir are used for treatment of herpes outbreaks. These drugs are most commonly taken orally, but a topical option is available for orolabial lesions and may decrease viral shedding. These medications are effective at limiting duration of symptoms but do not cure patients of the virus. These same medicines, used in a preventative fashion, prolong symptom-free disease recurrence in approximately 50% of infected patients.

Please refer to Chapter 10 for a more detailed discussion of herpes simplex.

Measles. Measles is single-stranded RNA virus in the paramyxovirus family. The incidence of this disease has been greatly reduced by the institution of vaccination programs in most developed countries. Rare cases of vaccine failure can occur and not all persons accept immunization recommendations. This disease is transmitted by direct contact of aerosolized particles. Symptoms usually begin one to two weeks after exposure and consist of cough, coryza, conjunctivitis, pharyngitis, lymphadenopathy, and fever. Mucosal lesions consisting of gray-white spots surrounded by an erythematous base are the hallmark physical exam finding and are referred to as Koplik's spots. Shortly after these initial presenting symptoms develop, a maculopapular rash begins on the head and neck and progresses toward the extremities. Diagnosis is clinical in most cases. The virus can be cultured if needed, and serological tests are available. Treatment is supportive and symptoms are self-limiting, lasting around two weeks. Bacterial superinfections should be treated accordingly. Vaccination for disease prevention is currently recommended and commonly given as a triad with mumps and rubella.

Human Immunodeficiency Virus. HIV is a retrovirus that infects CD4+ lymphocytes and monocytes. It is transmitted by sexual contact, blood transfusions, needle-stick injuries, maternal/fetal transmission across the placenta, and maternal breast milk consumption. Acute prodromes of HIV infection include fever, malaise, cervical lymphadenopathy, and pharyngitis. Initial presentation is often confused with infectious mononucleosis and diagnosis is often delayed. These symptoms are usually self-limiting and resolve in approximately 7 to 10 days. Opportunistic infections with diseases such as HSV, CMV, and candida are the hallmark of this infection as CD4+ counts plummet.

There are several tests available for HIV. The most commonly used are ELISA and immunoblotting (Western blots). PCR techniques and viral cultures are also used and may be more sensitive than traditional ELISA and Western blot assays. Newer tests utilize buccal mucosal swabs in place of serum. Treatment of HIV itself consists of multiple antiviral regimens combined in a "cocktail" protocol. Treatment of coinciding opportunistic infections is performed as indicated, and preventative medications are often used when CD4+ counts are decreased. Symptomatic relief with topical anesthetics or special mouthwashes containing combinations of steroids, carafate, benadryl, and Maalox may be beneficial when symptoms of pharyngitis persist.

HIV is discussed in detail in Chapter 16.

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