A little boy is hospitalised with a widespread, severe and distressing rash.
CASE HISTORY
A boy with a history of eczema was admitted to hospital the day before his second birthday.
The child had first developed eczema at the age of three months. There was no history of eczema or atopy in the immediate family.
His mother described his eczema as moderate to severe and worse in the flexures of his upper and lower limbs. She used topical steroids and paraffin gauze dressings at home to manage his skin condition.
Born by caesarean section at 36 weeks due to his mother having idiopathic thrombocytopaenia, his immunisations were up to date and he was thriving.
Neither the child nor any of his immediate family had a history of cold sores.
Five days prior to admission, his mother noted a flare of his eczema, with the formation of widespread vesicles and pustules. At this time the child was quite well, with a normal oral intake, no fevers and only minimal distress.
His concerned mother took him to the local emergency department, but he was discharged for outpatient follow-up.
Over the ensuing days, the child became febrile and increasingly distressed. He refused any solid intake and was only tolerating small amounts of fluid. Oral antihistamines and paracetamol provided minimal relief and his mother returned with him to the emergency department.
Figure 1.
Figure 2.
Figure 3.
CLINICAL PRESENTATION
On examination, the child had a widespread vesicular rash on an erythematous base with pustules and secondary changes of excoriation with weeping and crusting (Figures 1 and 2).
The rash was worse over the dorsum of the hands (Figure 3) and in the flexures, with relative sparing of the face.
A provisional diagnosis of eczema herpeticum was made, and swabs of the lesions were taken for bacterial culture and sensitivity, viral culture, herpes simplex virus (HSV) direct immunofluorescence (DIF) and HSV polymerase chain reaction (PCR).
Intravenous access was obtained and blood samples were sent for HSV serology, full blood count, C-reactive protein, urea, creatinine and electrolytes.
While awaiting investigation results, the child was commenced on intravenous aciclovir and cephazolin. Topical treatment with glucocorticoids, sorbolene and wet dressings three times daily was instituted along with oral antihistamines.
The DIF and later PCR confirmed HSV1 infection, and treatment with oral valaciclovir was then instituted. The wet dressings, moisturisers and topical steroids were continued.
DISCUSSION
Eczema in children
Eczema, also referred to as atopic dermatitis, is estimated to affect 15%-20% of children, and its prevalence is said to be increasing.
Eczema usually develops before one year of age, and in most cases before five years of age. It commonly initially develops on the face, followed by the flexures. There is often sparing of the nappy area.
It is characterised in infancy by pruritic, red, scaly and crusted lesions. In children, secondary lichenified plaques are often present in the antecubital and popliteal fossae, volar aspect of the wrists, ankles and neck.1
Complications of eczema
- Superimposed bacterial infection – most commonly Staphylococcus aureus and streptococcal species≤/li>
- Superimposed viral infection – most commonly HSV
- Sleep disturbance and secondary behavioural problems as a consequence of nocturnal pruritus
- Stress – experienced by parents/carers dealing with this condition
- Anxiety (in older children) over physical appearance.
Eczema herpeticum
Aetiology
Eczema herpeticum is a herpes simplex virus (type 1 or 2) infection with disseminated skin involvement occurring in a patient with atopic dermatitis.
It is characterised clinically by disseminated monomorphic vesiculopustules, crusted papules and erosions often accompanied by fever, malaise and lymphadenopathy.2
It can be caused by both primary and secondary HSV infection.
Eczema herpeticum can range in severity from localised, mild disease to disseminated and fatal disease. Ocular disease (e.g. ulcerative keratitis) may accompany the condition and cause visual loss as a result of corneal ulceration.3
Clinical presentation
The diagnosis is mainly clinical and should be considered in patients presenting with exacerbation of atopic dermatitis not responding to simple measures, especially if they have systemic symptoms.
Recent contact with a herpes-infected person is relevant in primary HSV infection, as is a personal history of herpes for reactivation of latent infection in the individual.3
Investigations
Laboratory tests to support the diagnosis include PCR for HSV, viral DNA on blister fluid, immunofluorescence for viral antigens, swabs in viral medium for viral culture, and viral serology.4
Bacterial swabs should also be taken since bacterial superinfection often accompanies eczema herpeticum and is also a differential diagnosis.
Management
As eczema is so common in infants and children, it is important for all general clinicians to be aware of the general principles of management of the condition and signs that complications have developed.
The management of uncomplicated eczema involves education, avoidance of triggers and allergens, and the liberal use of emollients.
Mild flares can usually be managed with topical steroids, cool compresses and wet dressings and the use of antihistamines at night.5
The recommended treatment for eczema herpeticum is oral aciclovir/valaciclovir in mild cases. If the child is unwell, febrile or less than three months of age, intravenous (IV) aciclovir should be used initially.
The duration of IV therapy should be determined on an individual basis, but the course of antiviral therapy (IV and oral) should run for 10 days.5
Suspected bacterial infection should be treated with oral cephalexin or flucloxacillin unless the child is very unwell, febrile, less than six months of age or there is threatened eye involvement. In these cases, IV therapy is required, the duration of which is determined on an individual basis.
Patients should complete a combined 10-day course of antibiotic after IV therapy is changed to oral.5
Antiseptic (triclosan 2%) bath oils can control recurrent bacterial infections.
REFERENCES
1. Habif TP. Atopic Dermatitis (chapter 5). In Clinical Dermatology: A Color Guide To Diagnosis And Therapy. Mosby, Edinburgh 2004; pp105-128.
2. Wollenberg A, Zoch C, Wetzel S, Plewig G, Przybilla B. Predisposing factors and clinical features of eczema herpeticum: a retrospective analysis of 100 cases. Journal of the American Academy of Dermatology 2003;49(2):198-205.
3. Feye F, Halleux CD Gillet JB, Vanpee D. Exacerbation of atopic dermatitis in the emergency department. European Journal of Emergency Medicine 2004;11(6):360-62.
4. Klein RS. Clinical manifestations and diagnosis of herpes simplex virus type 1 infection. UpToDate, June 2006, http://patients.uptodate.com/topic.asp?file=viral_in/5714.
5. King E, Lee O, Orchard D, Su J, Varigos G. Eczema Management. Clinical Guidelines, Royal Children’s Hospital, Melbourne, 2006, http://www.rch.org.au/rchcpg/index.cfm?doc_id=9971 (accessed 23 October 2007).
Dr Michelle Julian, MBBS, RMO, Department of Dermatology, St George Hospital, and Associate Professor Dedee F Murrell MA(Cambridge), BMBCh(Oxford), FAAD(USA), MD(UNSW), Head, Department of Dermatology, St George Hospital, UNSW, Sydney.