Enteroviruses cause most summer colds. The enteroviruses include echoviruses, coxsackieviruses, numbered enteroviruses, and the polioviruses. Most summer colds seen in private practice are self limited, presenting with fever alone or clinically distinctive pictures such as hand-foot-and-mouth disease (HFMD), herpangina, or pleurodynia. However, enteroviruses also cause serious illnesses such as meningitis, myocarditis, encephalitis, and neonatal sepsis. Enterovirus infections often are confused with bacterial infections and treated unnecessarily with antibiotics.
Enteroviral infections spread predominantly by the fecal-oral route. Contaminated swimming pools also may serve as a source of transmission. Enteroviruses colonize the respiratory and the gastrointestinal tract. The infection spreads to the lymph nodes, where the virus replicates and an initial viremia occurs on approximately the third postexposure day. The viremia results in subsequent spread to the throat (herpangina), and/or hands and feet (HFMD), lungs (pleurodynia), heart (myocarditis) or meninges (viral meningitis). Infection at the secondary sites corresponds to the onset of clinical symptoms 4-6 days after exposure. The clinical manifestations of enteroviral infections result from the damage caused by the virus at the secondary sites of infection.
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Enterovirus pharyngitis starts abruptly and often is accompanied by fever. Younger children may present with increased drooling, hands in the mouth, and refusal to eat. Older children complain of sore throat as well as headache, myalgias, and malaise. Mild vomiting and diarrhea commonly accompany the respiratory symptoms. Herpangina is a specific syndrome of enterovirus pharyngitis; children with this syndrome have fever and characteristic papulovesicular lesions on the anterior tonsillar pillars, soft palate, uvula, tonsils, and pharyngeal wall. The lesions are discrete and average five per patient. They do not appear in the anterior part of the mouth.
Hand-foot-and-mouth disease is well recognized by clinicians who care for young children. The child presents with fever and papulovesicular lesions within the mouth that quickly become ulcerated and papulovesicular lesions on the palms and soles. The palms and soles often are puffy and red, and the child may act as though her hands and feet hurt, refusing to use her hands or walk. The fever accompanying herpangina and HFMD usually lasts 3 or 4 days, but fever that persists for a week is not uncommon. The pharyngitis follows a pattern similar to the fever.
Pleurodynia has a sudden onset of pain in the chest or upper abdomen. The pain appears to be muscular in origin; its intensity varies. It can be excruciatingly severe and accompanied by sweating and pallor. Older children describe the pain as sharp and stabbing. It occurs in spasms that can last for a few minutes to a few hours. During spasms, the patient has rapid, shallow respirations that suggest pneumonia. The symptoms usually last 1 or 2 days, but the illness can be biphasic, with symptoms resolving only to reappear a few days later.
Gastrointestinal manifestations are almost universal in enterovirus infections. The most common symptoms are anorexia, nausea, vomiting, and diarrhea. They usually are not severe and often occur in combination with other symptoms, such as fever and sore throat. Abdominal pain may be the only manifestation of infection; when severe, it can mimic appendicitis.
Enterovirus infections once were thought to be mild diseases that lasted 2-3 days. But a study of 380 children aged 4-18 years during July to October from private pediatric practices found that illness is prolonged in many patients (Pediatrics. 1998 Nov;102[5]:1126-34). The mean duration of illness was found to be 10 days for myalgia-malaise syndrome, 7 days for herpangina, and 7 days for HFMD.
Spread of enteroviral infections within a household was common. More than 50% of children studied had a family member with enterovirus illness. Half of siblings and 25% of adults within the household of the index case contracted an enteroviral infection. Some had the same presentation as the index patient, but it was not uncommon for other household members to have quite different presentations. For example, the first child seen might present with hand-foot-and-mouth disease, and a few days later a sibling might be brought for care with myalgia-malaise, and the parent might appear ill and complain of pleurodynia.
Summer colds can be costly to families. The duration of the illness and the multitude of nonspecific symptoms sometimes leads to concern about a possible bacterial cause, which prompts a diagnostic workup, including laboratory tests and empiric treatment with antibiotics. The direct costs vary with the syndrome; stomatitis and HFMD are the least expensive to treat because the clinical picture is diagnostic with a single office visit, but a severe manifestation such as aseptic meningitis are expensive to treat with associated emergency department visits, spinal tap, and sometimes hospitalization.
Dr. Michael E. Pichichero
Dr. Pichichero is a specialist in pediatric infectious diseases and director of the Research Institute at Rochester (N.Y.) General Hospital. He reported having no conflicts of interest. Email him at pdnews@mdedge.com.