Paediatrics: Skin infection: viral and bacterial

Skin infection: viral and bacterial

Viral

Warts

Very common. Caused by infection with human papilloma virus. May affect any age, but mainly school-aged children. Warts exists as painless firm papules with rough hyperkeratotic surface. Capillary ends can usually be seen superficially. Typically affect hands, knees, face, and feet. Usually resolve spontaneously within 3yrs.

·  Plantar warts (verrucae) may be painful due to pressure-induced in growing.

·  Genital or perianal warts (condyloma acuminata) may occur and, although sexual abuse should be considered, causation is commonly innocent.

Treatment

Not usually needed. If painful or embarrassing:

·  keratolytic agent (e.g. salicylic acid);

·  liquid nitrogen cryotherapy;

·  immunotherapy;

·  surgical removal.

Molluscum contagiosum

Herpes simplex

Most cases due to type I HSV. Type II HSV typically causes genital herpes.

Co-infection with active atopic eczema causes eczema herpeticum.

Primary infection

Typically occurs in pre-school children with sore throat, stomatitis, vesicles or ulceration involving mouth, lip, face, and fever. It resolves within 2wks.

·  s bacterial infection frequently occurs.

·  Treat with antipyretics, analgesic mouthwashes, or throat lozenges, topical aciclovir cream. Consider NGT fluids if child becomes dehydrated due to reluctance to swallow. Treat any bacterial s infection.

Secondary reactivation

Manifests as initial itch or tingling followed by localized vesicles that then break down. Typically lesions are perioral (cold sore). May be idiopathic, but can be precipitated by illness, immunosuppression, menstruation. Early topical aciclovir cream aborts episode or reduces its severity.

Chickenpox (varicella)

This is a very contagious infection due to Herpes zoster. Chickenpox with fever, followed by pruritic vesicular eruption over the trunk spreading to face, mouth, and limbs. Lesions evolve at different rates so that macules, papules, vesicles, and pustules will all be present at once. Secondary bacte-rial skin infection may occur. Illness may cause life-threatening pneumonitis in congenital infection, older teenagers, or immunosuppressed. Infectivity lasts until FINAL vesicle crusts over.

Treatment

·Antipyretics.

·Oral antihistamines.

·Cooling baths.

·Topical calamine lotion.

·IM human-specific Varicella zoster immunoglobulin (VZIG) should be given early if risk of severe illness (IV aciclovir in severe illness).

Reactivation (shingles)

Can occur in childhood, particularly when varicella occurs <1yr old. May be severe in immunosuppressed. Presents with localized unilateral pain, itching, or hyperaesthesia, followed by vesicular eruption in the distribu-tion of affected dorsal root ganglia. Treat with oral aciclovir if severe and topical antibiotics if s bacterial infection.

Hand, foot, and mouth disease

Infection with coxsackie or enterovirus 71, usually in pre-school children. (Note: Completely different infection from foot and mouth disease in ani-mals!) Painful small vesicles (may be linear or oval) affect mouth (stomati-tis), palms, and soles, and occasionally nappy area. Lesions spontaneously resolve within 10 days. If uncertain a viral swab can confirm the diagnosis and also exclude potentially more serious HSV/VZV infection.

Treatment 

Symptomatic.

Bacterial

Impetigo

Erysipelas/cellulites

Furuncle (boil)

·Confluence of furuncles = a carbuncle.

·Hair follicular abscess (boil) is usually due to Staphylococcus aureus infection. Common in post-pubertal males.

·Tender superficial red papule develops into large painful inflamed pustule that ultimately discharges superficially.

·Affects mainly the back, axilla, and buttocks.

·Associated with diabetes mellitus and poor hygiene.

·Recurrent or severe furuncles require surgical drainage, oral flucloxacillin, and daily chlorhexidine baths to decrease S. aureus skin colonization.