Common skin infections in children: Folliculitis and herpes

In the fourth part of our series about common skin infections in children, Michael J Sladden and Graham A Johnston review folliculitis and herpes

Childhood skin infections are commonly seen in both primary care and dermatology practice worldwide. They consume considerable resources and need careful management. However, education and reassurance of patients and parents, combined with simple treatment and self management, play a vital part in successful treatment. We recently reviewed six common childhood skin infections: molluscum contagiosum, cutaneous viral warts, impetigo, tinea capitis, scabies, and head lice. We now review two more skin infections commonly seen in children, des­cribing the epidemiology, clinical features, and treatment of each. For conditions with limited evidence, we provide pragmatic advice and ­recommendations.

Sources and selection criteria

We searched Medline, Embase, and the Cochrane Library by using the terms "folliculitis," and "herpes simplex virus." We included randomised trials, reviews, meta-analyses, and guidelines.

Folliculitis

Folliculitis is a superficial inflammation of the hair follicles. It is common and can occur at any age.¹ It is usually caused by bacteria, particularly Staphylococcus aureus, but can also be caused by Pityrosporum. Persistent bacterial folliculitis can be caused by diabetes, friction from tight jeans, occlusive dressings, and shaving.

Folliculitis begins as inflammation of the follicular ostium and can be pruritic or painful. The lesions develop into 1-5 mm yellow-grey papules or pustules, with surrounding erythema, confined to the follicular ostia (fig 1). They can be grouped or discrete and usually occur on the scalp, face, buttocks, and extremities. There are usually no systemic symptoms.

Fig 1 Grouped yellow-grey papules and pustules of
folliculitis, surrounding the erythema

Uncomplicated folliculitis is managed by removing causative factors and cleansing with topical antiseptics. Antiseptics, including chlorhexidine, triclosan, and povidone-iodine, can be used as creams or lotions, soap substitutes, and bath additives. Emollient-antiseptic combinations, such as Dermol (Dermal Laboratories) and Oilatum Plus (Stiefel Laboratories), may be particularly useful in children to reduce skin irritation.

Resistant lesions respond to topical mupirocin or fusidic acid. Resistance to fusidic acid is increasing, however, and it should be used only for short periods (2 weeks).

For severe or refractory folliculitis, we recommend that systemic antibiotics should be used empirically, as for impetigo, depending on local bacterial resistance patterns and individual tolerability.¹ Gram stain, culture, and sensitivity of lesion exudate confirm the diagnosis and guide treatment. If the infection of the follicle is deeper and involves more follicles it develops into the furuncle and carbuncle stages and usually needs incision and drainage.¹ Nasal swabs should be taken from the patient and immediate relatives to identify asymptomatic carriers of S aureus.² Nasal mupirocin is particularly effective at eliminating nasal carriage.

Cold sores (herpes simplex virus)

Herpes simplex virus (HSV) infection is very common and typically results in mucocutaneous disease.³ It is transmitted by mucosal or skin contact from an infected person shedding virus. HSV-1 usually causes orofacial disease, and HSV-2 causes genital infection. In this review, we focus on cold sores (Herpes labialis) and exclude genital and neonatal HSV.

Primary herpetic gingivostomatitis is self limiting but can range in severity from virtually asymptomatic to severe infection with oral ulceration, sore throat, lymphadenopathy, pain, and fever. We recommend treatment of symptoms, topical aciclovir, and, if indicated, systemic aciclovir for 7-10 days.

Cold sores occur when latent HSV is reactivated. A prodrome of tingling and itching is followed by development of an erythematous plaque with grouped vesicles. Cold sores are usually localised and self limited, but they can be recurrent. Although they usually occur on the lip, they can occur anywhere on the face or body and are more difficult to diagnose at these sites. HSV is the most common cause of erythema multiforme,⁴ but, more importantly, it can cause eczema herpeticum in patients with pre-existing atopic eczema.

Prophylactic oral antiviral agents may reduce the frequency and severity of cold sore attacks in adults.⁵ Although no trials of prophylactic treatment have been done in children, those with confirmed frequent recurrences may also benefit from suppressive treatment. We suggest oral aciclovir 400 mg twice daily (half this dose for children under 2 years) for 6-12 months, depending on response. Topical aciclovir does not prevent recurrent attacks.⁶

Erythema multiforme is an acute, self limiting, feverish eruption characterised by vesiculo-bullous target lesions (fig 2) in a symmetrical and acral distribution.⁷ Spontaneous resolution occurs in a few weeks, but recurrences are frequent and oral involvement can impair quality of life. In recurrent erythema multiforme, early treatment of HSV with oral acyclovir may prevent erythema multiforme, but often treatment is started too late. For these children, prophylactic oral aciclovir may prevent episodes of both HSV and erythema multiforme, even when HSV is not the obvious precipitant of erythema multiforme.^8-9

Fig 3 Typical targetoit of lesions of erythema multiforme

Eczema herpeticum (Kaposi's varicelliform eruption) is a widespread HSV infection superimposed on pre-existing (often mild) atopic eczema. Widespread vesicles and erosions (fig 3), fever, and malaise occur. The first episode is the worst, and it can be recurrent. Mild cases can be treated with oral acyclovir, but more severe cases need admission to hospital for intravenous antiviral treatment. Treatment of the primary skin disease is essential (although topical steroids should be withheld during the acute phase), and antibiotics are indicated for secondary bacterial infection. Prophylactic oral aciclovir is indicated for recurrent disease.

Fig 3 Classical eczema herpeticum,showing extensive vesicles and erosions

Competing interests: MJS has been co-investigator in trials sponsored by Merck, Sharp and Dohme; this included speakers' honorariums and travel expenses. GAJ has received speakers' honorariums and travel expenses from Galderma, UCB Pharma, Shire, Leo, and Steifel. He has acted as a consultant to Novartis in a peer review of drug trial protocols. He has been co-investigator in a trial sponsored by 3M Pharmaceuticals.

Michael J Sladden, clinical epidemiologist and specialist registrar in dermatology,
Email: m.sladden@doctors.org.uk

Graham A Johnston, consultant dermatologist, Department of Dermatology, Leicester Royal Infirmary, University Hospitals of Leicester NHS Trust

This article is adapted from one first published in the BMJ (2005;330:1194-8).

studentBMJ 2005;13:265-308 July ISSN 0966-6494