Infectious diseases in children: Herpes simplex

Herpes simplex is a common infection in childhood but often goes unrecognised. In this article, we explain what it is, the important differential diagnoses and, most importantly, how to provide good care and helpful advice

Childhood herpes simplex infection is common, and it will often present to the practice nurse, usually as a poorly child with a sore mouth. It often goes undiagnosed, and this misses a chance for useful supportive advice and care. Importantly, though, it also misses opportunities for advice about limitation of spread. Moreover, understanding and management of those few children who need secondary care help may be delayed as a result.

WHAT IS HERPES SIMPLEX?

Herpes simplex is a virus. There are two herpes simplex viruses, type 1 and 2. Most oral herpes is still type 1, particularly in children. Adult genital herpes, which is sexually transmitted, used to be considered mainly type 2, but in fact there is much more mixing than this – about a third of genital herpes is type 1 and some oral herpes is type 2. However most herpes simplex gingivostomatitis is type 1, referred to as HSV1.¹

Primary herpes simplex infection is most commonly asymptomatic, but when it does cause symptoms, they are predominantly gingivostomatitis in young children and pharyngitis in teenagers. After infection, like another familiar herpes virus (herpes zoster) the virus likes to hide away in nerves and is famous for reactivating at a later stage, in the case of herpes simplex, as a cold sore.

There are a few other manifestations of the virus – herpetic whitlow, eczema herpeticum and herpes simplex encephalitis. These are discussed below – but while important and serious, these are relatively rare.¹

HOW COMMON IS IT?

Herpes simplex is widespread – the great majority of UK adults have serological evidence of having had the infection, but most never get cold sores.

Primary infection is usually in childhood and the most common presentation is as gingivostomatitis, which occurs in 10-25% of primary infections. It is most common in preschool children: peak incidence is at 2-4 years of age.

TRANSMISSION

HSV1 is spread through saliva. Kissing, using the same eating utensils and sharing personal items such as flannels can transfer the virus from one person to the next. The virus then gets into the body through mucous membranes such as the lips and nasal lining. Incubation period is 3-10 days.

Little children catch herpes simplex through being kissed by parents and friends, sharing face flannels, and from contact with other children.

Because adults may shed herpes simplex virus in the saliva without an active cold sore (it can be shed before a cold sore appears, for up to two months after it has gone, or without ever having a cold sore at all) then herpes simplex is passed on silently. It is probably much less infectious when there’s no cold sore – but transmission can still occur. It’s so widespread that it’s difficult to do much about it. Moreover only about 10% of affected children get the obvious gingivostomatitis that characterises primary HSV infection, so for the most part it is silent and essentially harmless.^1,2

HERPETIC GINGIVOSTOMATITIS

This occurs in 10-25% of children at the time of their first infection with herpes simplex type 1. It causes an acutely sore mouth, with sore red gums and often lots of punched out ulcers and – earlier in the infection – vesicles on the gums, tongue and tongue. There may be bleeding from sore inflamed gums, and the blisters often join up to form large ulcers. HSV gingivostomatitis typically lasts 2-3 weeks, although the worst of the soreness usually lasts only a week or so.

Herpes simplex mouth infection is very unpleasant for the child, whose entire mouth is extremely painful. They often have a temperature and lymphadenopathy, and they are systemically unwell, so the differential diagnoses are important to consider (see Box 1). They are typically drooling as even dealing with saliva is painful – and breath often smells bad.

However, the main problems are usually soreness of the mouth and reluctance to eat and – more importantly for short-term health – to drink in children who may be too young to understand why they need to try. Dehydration is therefore the commonest complication needing admission to hospital

The important things for parents to know are that this condition cures itself, but that it is extremely contagious to uninfected individuals (mainly other young children). So children may need to be kept at home.

Support for the parent and practical suggestions to help the child maintain a fluid and calorie intake are very important. See ‘Advice to parents’.

DIAGNOSIS

Suspect primary HSV infection in any child with mouth ulcers, particularly if multiple or severe. Differential diagnosis is shown in Box 1.

TREATMENT

In most cases the management is mainly supportive with particular emphasis on keeping the child well hydrated. The oral lesions are painful and topical acyclovir makes little difference. In any case most children are very distressed by attempts to touch the lesions.

Oral antivirals are not routinely recommended,^3,4 as the risk of side effects is felt to outweigh the benefit (although there is evidence that they slightly reduce duration of the episode if given in the first three days). They are sometimes used for children admitted to hospital with dehydration secondary to gingivostomatitis

ADVICE TO PARENTS

An explanation of the condition is enormously helpful, together with information for the parent on what to expect in terms of severity and duration.

Parents need tips and advice for mouth care in their child and for maintenance of drinking, and they need to know when to seek help if things get worse.

Pain relief

• Paracetamol seems to be of little benefit, ibuprofen may be a little better.
• Anaesthetic mouthwashes might be helpful but children don’t tolerate anything in the mouth well, and as these may sting they are of limited benefit.^3,4

Food and drink

Advise parents as follows:

• Fluids are vital.
• Calories can be liquid: lack of a balanced diet or solid food for two weeks is not important if the child can’t eat, where as lack of fluids is a problem.
• A straw may help, particularly with blisters on the tongue
• Ice creams, iced drinks and cold foods such as jelly and yogurt are tempting to most children
• Cold drinks help soothe the mouth and numb the pain.
• Good choices are milk, milkshakes, and clear liquids. Avoid citrus or carbonated drinks, as they will cause the child’s mouth to hurt more.
• The child may not feel like eating solid foods. Offer soft foods such as mashed potatoes, yogurt, and ice cream. Avoid salty, spicy, and hard foods.
• After each meal, rinse the child’s mouth with warm water.
• Wash toys that the child puts in his or her mouth before and after they are played with.
• Don’t let the child share his or her toothbrush, drinks, or food with others. He or she should also wash hands before eating and after going to the bathroom.
• Children will not develop bad eating habits just because they have milkshake when unwell

Rehydration

Oral rehydration sachets may help a child who is getting dry – but if the child won’t drink anything at all then ice creams and ice lollies may be a more effective way of getting them to take fluids.

When to seek help

Advise parents to seek medical help if:

• The child has a temperature of 100.4° F (38° C) or higher.
• The child is dehydrated from not getting enough fluids. This may be suspected if:
  • He or she has not urinated in 8 hours.
  • The soft spot on the top of the head is sunken (in babies).
  • He or she has no tears when crying.
  • Lips are dry and cracked.
  • He or she is weak or sleepy and hard to wake up.

OTHER HSV1 INFECTIONS IN CHILDREN¹

Generalised herpes simplex infection in the newborn

This is very serious, overwhelming herpes infection that occurs when a mother with active genital herpes of type 1 or 2 passes the infection to her baby during vaginal birth. It can cause a disseminated viral infection affecting internal organs, or affect the central nervous system and lead to encephalitis (see below). Both manifestations are associated with high morbidity and mortality.

Eczema herpeticum

Eczema herpeticum is a severe primary herpes skin infection that may occur in individuals with eczema. There are widespread herpetic lesions over the affected skin and areas of rapidly worsening, painful eczema. There are clustered blisters and punched-out ulcerated lesions, usually 1–3 mm across, which may coalesce and crust. The child may have fever and be lethargic and visibly ill. Admission to hospital is needed for intravenous antivirals, antibiotics and specialist nursing care.

Herpetic whitlow

This is a painful cutaneous infection that usually affects the distal third of the fingers. It is caused by herpes simplex virus (HSV) types I or II either as the primary infection or a secondary recurrence. It is often seen in children due to autoinoculation from oral herpes e.g. in thumb suckers with gingivostomatitis or recurrent cold sore.

Herpes simplex encephalitis

Herpes simplex encephalitis is a rare but devastating complication of the virus. The very young and the immunosuppressed are more at risk. Encephalitis is inflammation of the substance of the brain – in this case due to infection. Children have fever, altered consciousness and often seizures. Most affected children do not have other outward signs of herpes infection such as oral ulceration. Treatment is, obviously, in hospital.

SUMMARY

Primary oral herpes simplex is common, but often missed. Parents may be upset to know the diagnosis and cause, as most UK adults who are HSV positive are unaware they have ever been exposed to the virus.

The practice nurse is well placed to diagnose and manage this condition, to offer clear explanations and supportive care, and to offer to review those children who seem to have the potential to need hospital admission.

REFERENCES

1. Lissauer T and Clayden G. Illustrated Textbook of Paediatrics. 4th edition. London; Mosby: 2007

2. NICE Clinical Knowledge Summaries. Herpes simplex – oral. Available at: http://cks.nice.org.uk/herpes-simplex-oral

3. Cunningham A, Griffiths P, Leone P et al. Current management and recommendations for access to antiviral therapy of herpes labialis. J Clin Virol. 2012 Jan;53(1):6-11. 2011

4. Clinical Practice Guidelines: HSV Gingivostomatitis. Available at: http://www.rch.org.au/clinicalguide/guideline_index/HSV_Gingivostomatitis/