Treating common skin infections in children
Skin infections commonly affect children of all ages. Although more common in those with underlying skin disorders such as atopic dermatitis, the infections can also occur in children without a history of skin disorders. Some skin infections are self-limiting (eg, molluscum contagiosum) and resolve even without treatment. Others such as impetigo may be managed in the primary care setting.
Rarely, skin infections may lead to morbidity and even mortality in children (eg, eczema herpeticum and staphylococcal scalded skin syndrome). The role of a primary care physician is to not only be able to treat simple skin infections but also to identify more dangerous conditions in time for tertiary referral. Outlined below are some common skin infections seen in children, along with suggestions for their diagnosis and treatment.
Molluscum contagiosum (MC) is caused by a member of the poxvirus family. It is a common skin infection in children and adolescents. Spread by direct contact, it presents with single or multiple skin-colored, dome-shaped papules, commonly with a central umbilication (Figure 1).
MC is usually a self-limiting condition and can be left to self-involute over 6-12 months. An eczematous rash appearing around the lesions usually heralds self-involution over the next few weeks or months.
Treatment options, if required, include topical applications (eg, tretinoin or imiquimod), curettage, cryotherapy, pricking and expressing, and electrocautery.1,2
Viral warts, caused by the human papillomavirus (HPV), are a very common skin condition in children and adults.3 Warts are spread by direct contact, and can occur on almost any area of the skin, but most commonly occur on the hands and feet. On the palms and soles, they appear as papules with overlying thickened skin, punctuated by thrombosed capillaries and loss of overlying skin lines. Plane warts, most commonly occurring on the face, present as skin-colored, flat-topped papules, sometimes in a linear configuration (Koebner’s phenomenon). Warts on other areas of the body can appear as filiform tumors (Figure 2).
A simple home-based treatment is the nightly use of a keratolytic agent, such as Duofilm or Verrumal. After application, the wart can be covered by a strip of duct tape which is removed in the morning. This should be done for 4 to 6 weeks before assessing treatment response. Other treatment options in the clinic include cryotherapy, electrocautery and ablative laser therapy.
However, these procedures may cause significant pain and distress to a young child. The use of a topical anesthetic cream before treatment may reduce the severity of pain. In children, warts may resolve spontaneously, although this may take up to 2 years.4
Herpes simplex virus infections
Herpes simplex virus (HSV) infections in children are most commonly caused by HSV I, and less commonly by HSV II. Herpes gingivostomatitis is the most common type of primary herpes in children, presenting as multiple, grouped, small blisters and erosions over an erythematous base.
It can involve the lips, gums and tongue. Associated systemic symptoms include fever, lethargy and irritability. Severe infections can lead to poor food intake and dehydration in a young child. Herpes labialis (“cold sores”) are common in children and adults and present as a localized, small-grouped, painless or painful blisters and erosions on the lips and around the mouth. Eczema herpeticum is herpes infection occurring in patients with underlying skin disease, most commonly atopic dermatitis.5
Patients present with worsening of their underlying skin disease, accompanied by small, punctate, grouped erosions and blisters (Figure 3). Lesions can become generalized. Mild herpetic infections can be treated with saline or potassium permanganate soaks, and application of an anti-bacterial or anti-septic cream to prevent secondary bacterial infection. Severely affected patients may require inpatient supportive treatment and treatment with systemic anti-virals (eg, acyclovir or valacyclovir). Topical acyclovir cream can be used to shorten the duration of cold sores.6
The varicella-zoster virus causes chickenpox and herpes zoster (shingles). Chickenpox is a common childhood exanthema and is highly contagious. Early symptoms include fever, chills, myalgia and arthalgia. Skin lesions initially appear as red macules and papules, but quickly become vesicular and crusted. Lesions first appear on the face and trunk, before spreading to the extremities. New lesions continue to appear for the first week and spontaneously resolve after 2 weeks. Children immunized with the varicella vaccine may still develop chickenpox, although the disease is usually mild.7
Zoster is uncommon in children and presents with painful, grouped vesicles and erosions in a dermatomal distribution. Uncomplicated varicella infection can be managed conservatively. More severe infections can be treated with systemic anti-virals such as acyclovir and valacyclovir.
Impetigo is a common bacterial skin infection caused by Staphylococcus aureus, and less commonly, Streptococcus spp. It can occur on normal skin but also secondarily affects patients with underlying skin disease, especially patients with atopic dermatitis and discoid eczema.
Patients present with crusted, oozy, honey-yellow scaly papules and plaques. Lesions commonly occur around body orifices, such as the nose and mouth, and flaccid, soft blisters filled with clear or purulent fluid that easily rupture may also be seen. Young infants can develop staphylococcal scalded skin syndrome as a complication of impetigo. Treatment for impetigo includes normal saline or potassium permanganate soaks and topical anti-bacterial creams for mild, localized cases. More widespread involvement requires a 1-2 week course of oral antibiotics eg, cephalexin, cloxacillin or erythromycin.8
Scabies is caused by the Sarcoptes scabii mite. It can be contagious within families and close contacts, and can occur in all age groups, even in young infants. Patients develop extremely itchy, crusted and excoriated papules. Scabetic burrows may also be seen. Common sites include the web spaces, axillae, peri-umbilical region and genitalia. For infants, scabies can also affect the scalp. Topical permethrin is recommended for the treatment of scabies in infants less than 1 year of age. For the treatment of older children and adults, topical malathion or topical permethrin is recommended. All treatments should be repeated 1 week after the first cycle of treatment. It is important to treat all family members staying in the same household, even if they are asymptomatic. All bed linen should be thoroughly washed.9
Dermatophyte infections, kn-own more commonly as “tinea” or “ringworm”, are uncommon in children but may be seen in adolescents.10 Predisposing factors include obesity, poor hygiene and diabetes. Classification is based on the site of infection eg, tinea cruris (groin), tinea capitis (scalp), tinea pedis (feet) and tinea corporis (trunk). Patients present with annular patches or plaques with a central hyper-pigmented area surrounded by erythematous, scaly papules at the periphery. Lesions are usually pruritic.
Diagnosis can be confirmed by skin scrapings for microscopic examination with potassium hydroxide mount or by fungal cultures. Treatment options include anti-fungal shampoos (eg, selenium sulfide shampoo, ketoconazole shampoo), anti-fungal creams (eg, miconazole, clotrimazole) and oral anti-fungals (eg, itraconazole, griseofulvin, terbinafine).
Tinea versicolor (TV) is caused by a fungus, Malassezia furfur, which is part of the normal skin flora. It is uncommon in children but can occur in adolescents. Patients present with well demarcated, round-to-oval, scaly macules and papules most commonly over the chest, back, neck, arms and cheeks (Figure 4). Lesions may be hypo or hyper pigmented or skin-colored.
Patients may complain of itch. Microscopy of skin scrapings will reveal the fungus in a “spaghetti and meat-ball” configuration. Patients may be treated with anti-fungal creams (eg, clotrimazole, miconazole), shampoos (eg, selenium sulfide shampoo, ketoconazole shampoo) or oral anti-fungals (eg, itraconazole, ketoconazole).11 Advice on personal hygiene is important to prevent recurrence.
A complete list of references can be obtained upon request from the editor.