Paediatrics: Skin and soft tissues

Skin and soft tissues

Impetigo

•   Cause: staphylococcal or streptococcal skin infection.

•   Age group: infants and young children.

•   Features: erythematous macules (later vesicular/bullous) on the face, neck and hands—often associated with pre-existing skin lesions such as eczema.

•   Infectivity: nasal carriage is often the source of infection. Auto-inoculation occurs and lesions are infectious until dry.

•   Antibiotics: topical antimicrobials are often not useful in younger children due to scratching causing further spread of bacteria; if treatment required, use oral antibiotic, taking taste and formulation into account prior to prescription (oral flucloxacillin and erythromycin are often poorly tolerated).

Boils (furuncles)

•   Cause: Staphylococcus aureus.

•   Age group: any age.

•   Features: infecton of hair follicles or sweat glands.

•   Infectivity: nasal carriage is often the source of infection in recurrent boils.

•   Antibiotics: systemic.

Peri-orbital cellulitis

•   Cause: group A streptococcus, Staphylococcus aureus, Streptococccus pneumoniae, rarely Haemophilus influenzae type b in unimmunized children.

•   Age group: any age.

•   Features: fever with unilateral erythema, tenderness, and oedema of the eyelid, often following local trauma to the skin. Complications include local abscess, meningitis, and cavernous sinus thrombosis.

•   Investigations: if severe (eye movements are not visible or complete ptosis) refer to ENT or ophthalmology and perform cranial CT scan.

•   Antibiotics: IV ceftriaxone 80 mg/kg/od where eye movements are visible. Add IV metronidazole if eye movements not visible or not improved at 24hr.

Scalded skin syndrome

•   Cause: exfoliative staphylococcal toxin.

•   Age group: infants and young children.

•   Features: fever and malaise with a purulent, crusting, localized infection around the eyes, nose, and mouth. Later diffuse erythema and skin tenderness leading to separation of the epidermis through the granular cell layer. Nikolsky’s sign is epidermal separation on light pressure with no subsequent scarring after healing.

Antibiotics: IV flucloxacillin 50mg/kg/qds.

Necrotizing fasciitis

• Cause: group A streptococcus, less commonly Staphylococcus aureus

• Age group: any age.

• Features: SC infection of tissue down to fascia and muscle. Symptoms may be due to shock, systemic illness, and severe pain.

• Antibiotics: IV, and surgical debridement.

Toxic shock syndrome (TSS)

Cause

•   Toxin-producing staphylococci or streptococci

•   Multisystem disease due to staphylococcal toxin-1 in 75%

Signs and symptoms

•   Systemic illness with high fever

•   GI: vomiting, watery diarrhoea

•   Shock and hypotension, altered conscious level

•   Neuromuscular: occasional severe myalgia

•   Skin rash: red mucous membranes and diffuse macular rash; 10 days after infection desquamation of the palms, soles, fingers, and toes

Investigations

•   Haematology: thrombocytopenia, coagulopathy

•   Biochemistry: abnormal liver and kidney function

Diagnostic criteria for staphylococcal TSS

•   Temperature  39*C

•   Systolic blood pressure <90mmHg

•   Rash (may or may not include desquamation)

•   Involvement of three or more of gastrointestinal, musculoskeletal, renal, hepatic, CNS, blood, and mucous membranes

Diagnostic criteria for streptococcal TSS

•   Isolation of group A streptococcus

•   Hypotension

•   Involvement of two or more of coagulopathy, adult respiratory distress syndrome, soft tissue necrosis, rash with desquamation, or renal or hepatic involvement

Treatment

•   IV fluids and resuscitation

•   Antibiotics against staphylococci and streptococci. Clindamycin often added to flucloxacillin regime due to anti-toxin activity in vitro

·  IV immunoglobulin