A previously healthy 2-year-old boy is brought to the clinic with fever and mouth pain that began yesterday. He has consumed an adequate amount of fluids but refuses to eat due to the pain. The patient has no medical problems and takes no medications. Physical examination reveals swollen gums and vesicular, inflamed lesions on his hard palate and lips. He has enlarged and tender cervical lymph nodes. Which of the following is most likely responsible for this patient's condition?

Question

A previously healthy 2-year-old boy is brought to the clinic with fever and mouth pain that began yesterday.  He has consumed an adequate amount of fluids but refuses to eat due to the pain.  The patient has no medical problems and takes no medications.  Physical examination reveals swollen gums and vesicular, inflamed lesions on his hard palate and lips.  He has enlarged and tender cervical lymph nodes.  Which of the following is most likely responsible for this patient's condition?

Quizplus · Accepted Answer

11ec160b_3835_bd6c_9249_973dc79a0475_MD0001_00 Primary herpes simplex virus type 1 (HSV-1) infection is characterized by the gingivostomatitis (vesicles on the lips and hard palate, fever, lymphadenopathy) seen in this young patient. Recurrent HSV-1 infection causes lip lesions that are typically less severe due to existing cellular and humoral immunity from prior infection. HSV-1 and other herpesviruses are enveloped and possess double-stranded DNA genomes. Transmission is usually by direct contact with infected oral secretions or lesions. Inoculation occurs on mucosa or skin where the virus replicates rapidly in the host cell nucleus and causes abnormal cell division, resulting in intranuclear inclusion bodies and multinucleated giant cells visible on Tzanck smear. The vesicular lesions result from cell lysis and necrosis as well as tissue destruction, inflammation, and fluid accumulation between the dermis and epidermis. (Choice B) Most DNA viruses are double-stranded. They are enveloped (ie, surrounded by a lipid layer) or non-enveloped (ie, lacking a surrounding lipid layer). Adenovirus is a non-enveloped, double-stranded DNA virus that typically causes self-limited upper respiratory infection or gastroenteritis. (Choice C) Parvovirus is a single-stranded, non-enveloped DNA virus that causes erythema infectiosum, or fifth disease. Patients classically present with fever, cough, and rhinorrhea followed by a "slapped-cheek" and lacy, reticular truncal rash. (Choice D) Rotavirus, a type of reovirus, is a double-stranded, positive-sense, non-enveloped RNA virus. Rotavirus infection is a vaccine-preventable disease characterized by profuse, watery diarrhea in children. (Choices E and F) Most RNA viruses are single-stranded and can be classified as negative- or positive-sense viruses. Positive-sense viruses can be directly translated into proteins, but negative-sense stranded viruses must first have their RNA converted into positive-sense strands before translation. Coxsackievirus, a single-stranded, positive-sense RNA virus of the enterovirus family, causes hand, foot, and mouth disease, which presents with vesicular lesions on the buccal mucosa, tongue, and soft palate. The gums and hard palate are usually involved in HSV gingivostomatitis, not hand-foot-mouth disease. Educational objective: Primary herpes simplex virus type 1 (HSV-1) infection in children causes gingivostomatitis (vesicular lesions on the lips and hard palate). HSV-1 and other herpesviruses are double-stranded, enveloped DNA viruses. __________ References: The RNA synthesis machinery of negative-stranded RNA viruses. (http://www.ncbi.nlm.nih.gov/pubmed/25824479) Ultrastructure of the replication site of positive-stranded RNA viruses. (http://www.ncbi.nlm.nih.gov/pubmed/25746936)

A Previously Healthy 2-Year-Old Boy Is Brought to the Clinic