Enteroviral infections

Author: Vanessa Ngan, Staff Writer, 2008. Updated by Dr Jannet Gomez, Postgraduate Student in Clinical Dermatology, Queen Mary University, London, United Kingdom; Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, December 2016.


What are enteroviral infections?

Enteroviral infections cover a wide range of illnesses that are caused by a group of viruses called enteroviruses (EVs). They are members of the picornaviridae family which are small, icosahedral, single-stranded, positive-sense RNA viruses.

The most well known of the enteroviruses is the poliovirus (PV) but this has largely been eradicated. Other enteroviruses are the coxsackie A and B viruses (CVA and CVB) and the echoviruses (ECHO: enteric cytopathic human orphan).

How are enteroviruses classified?

Enteroviruses have been classified into 5 groups based on their molecular properties.

1. Poliovirus

  • PV1–PV3
  • Polio

2. Human EV A (HEV-A)

3. Human EV B (HEV-B)

  • CVA9
  • CVB1–CVB6
  • E1–E7, E9, E11–E21, E24–E27, E29–E33
  • EV69
  • CVBs are associated with epidemic pleurodynia, epidemic myalgia, myocarditis and pericarditis
  • E16 is the cause of Boston exanthema disease
  • E25 and E32 cause eruptive pseudoangiomatosis

4. Human EV C (HEV-C)

  • CVA1, CVA11, CVA13, CVA15, CVA17–CVA22, CVA24
  • CVAs are the main cause of herpangina and hand-foot-and-mouth disease

5. Human EV D (HEV-D)

  • EV68, EV70, EV73–EV75, EV77–EV78
  • HEV-Ds have been associated with gastrointestinal and respiratory illnesses

Enteroviruses are the cause of many illnesses including the common cold. Some of the coxsackieviruses, echoviruses and EV71 cause exanthems (skin rash or skin eruption as a symptom of a more general disease) or enanthems (rash on the mucous membranes). Cutaneous manifestations may be severe and atypical in some cases.

Who gets enteroviral infections?

Enteroviral infections are very common and it is estimated that more than one billion people worldwide are affected annually. In the United States 30,000 to 50,000 hospitalisations each year are due to enteroviral infections. People at risk include:

  • Infants and children
  • Neonates  acquiring  infection  from mothers
  • Immunocompromised patients
  • People in lower socio-economic groups.  

How are enteroviral infections spread? 

Enteroviral infections are highly contagious. Enteroviruses spread from person-to-person via:

  • Oral–oral routes; for example viruses are carried in respiratory droplets and transmitted when someone coughs and sneezes
  • Oral–faecal transmission
  • Direct contact with fluid from skin lesions
  • From mother to child in the peripartum period.

The incubation period for enteroviruses is usually 2–5 days. Once someone is infected the enterovirus implant and replicate in the alimentary tract.

If the infection remains local there is usually no symptoms. However, if the virus passes into the lymphatic system, generalised symptoms of un-wellness may develop. If the virus spreads into the bloodstream then more severe symptoms are experienced.

Cutaneous features of enteroviral infections 

Many enteroviruses cause diseases that have associated skin or mucous membrane reactions. 

Herpangina

  • Caused by Coxsackie group A , Coxsackie B, enterovirus 71, and echovirus
  • Lesions develop on the mucous membranes, most often on the anterior tonsils, uvula, and soft palate of the mouth
  • Lesions are characterised by grey-white tiny papulovesicles about 1–2 mm in diameter
  • Lesions are self-limiting and resolve over 5-10 days
  • Generalised symptoms include high fever, headache, sore throat, difficulty swallowing, vomiting and abdominal pain

Hand-foot-and-mouth

  • Caused by Coxsackievirus sA16 and enterovirus 71 
  • Oral lesions develop anywhere inside the mouth but most frequently appear on the hard palate, tongue, cheek and gums
  • Oral lesions begin as erythematous macules and papules (flat, inflamed red spots) 2–8 mm in diameter. These progress to form thin-walled vesicles (blisters) that burst and form painful ulcers surrounded by a red halo. These heal without treatment over 5–10 days.
  • Skin lesions appear along with or shortly after oral lesions develop. There may be a few lesions or more than 100 lesions and occur on the hands and the feet.
  • Skin lesions begin as erythematous macules or papules which quickly turn into small, grey vesicles surrounded by a red halo. These lesions resolve spontaneously over 7–10 days without scarring.

Boston exanthem disease

  • Caused by echovirus 16
  • After a short fever, pink macules and papules suddenly erupt on the face, trunk, and less commonly the extremities.
  • Small ulcers may also be found on the soft palate and tonsils.

Eruptive pseudoangiomatosis

  • Echovirus 25 and 32, coxsackie B, Epstein-Barr virus, and CMV
  • Cherry red lesions, usually no more than 10, develop on the face, trunk and extremities.
  • Lesions are 2–4 mm in diameter and red papules resembling cherry angiomas.
  • They resolve spontaneously within 10 days.

Below is a list of other cutaneous features that have been associated with the following enteroviruses.

What are the complications of enteroviral infections?

Less than 1% of enteroviral infections result in serious symptomatic illness. Occasionally, enteroviruses can cause severe heart and nervous system complications such as myocarditis, aseptic meningitis, meningoencephalitis and paralysis. 

How are enteroviral infections diagnosed?

Diagnosis is primarily based on the clinical findings.

Enteroviral PCR assays are helpful in confirming the pathogens.

Serologic testing and culture of virus are done in rare cases.

What is the treatment of enteroviral infections?

Treatment is limited to supportive therapy.

  • Hand washing (especially after diaper change) and personal hygiene
  • Disinfecting surfaces and objects 
  • Avoiding close contact 
  • Hydration with plenty of fluids
  • Antipyretics such as paracetamol for fever
  • Mouthwashes containing topical anaesthetics (lidocaine 2%) and antihistamines (eg, diphenhydramine hydrochloride) to relieve mouth pain.

Intravenous immunoglobulin has been used for the treatment of enterovirus  infection in symptomatic infants.

The antiviral drug pleconaril has shown to be effective treatment in some severe enteroviral infections. This is not available in New Zealand (December 2016).

What is the outcome of enteroviral infections?

Most enteroviral infections heal spontaneously within 7–10 days. Cutaneous lesions heal without scarring.

 

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