Paediatric Viral Cutaneous Infection

Overview Exanthem refers to the cutaneous manifestation of a viral illness (enanthem is the manifestation in the mouth). Historically, 6 exanthems have been recognised, 4 of which are viral. However, obviously there are much more common exanthems.

The six described are:

1. Measles (measles virus)
2. Scarlet fever (streptococcus pyogenes) - this is a bacterial infection and will not be discussed here
3. Rubella (togavirus virus)
4. ?
5. Erythema infectiosum (Parovirus B19)
6. Roseola infantum (human herpes virus 6 and 7)

Overview Also known as rubeola or first disease it is a highly contagious infection. Presents as an acute exanthematous febrile illness accompanied by conjunctivitis and koplik spots.

Aetiology

• Measles virus

Clinical features

• Prodromal phase
  • Coryzal symptoms
  • Marked malaise
  • Conjunctivitis
  • Fever
  • Koplik spots
• Exanthema phase
  • Maculopapular rash from face moving down to trunk
• Convalescent stage
  • Rash fades
  • Persistent cough improving

Measles rash - maculopapular rash extending from face to trunk and extremities

Koplik spots

Management

• Vaccination to prevent the disease is important
• Supportive treatment
  • Isolation (its contagious)
  • If Immunocompromised Antiviral and Vitamin A

Complications

• Encephalitis
• Subacute sclerosing panencephalitis
• Conjunctivitis
• Gastrointestinal - diarrhoea
• Otitis media
• Thrombocytopaenia → DIC

Overview Generally a mild illness, but can cause devastating congenital infection. Also known as german measles or third disease. It is a minor illness in children and adults, but devastating when transmitted in utero.

Aetiology

• Togavirus

Clinical presentation

• Fever
• Lymphadenitis retroauricular, posterior and occipital
• Pinpoint rash from face moving down to trunk (~3 days hence also called the 3 day measles)
• Forschimer spots
• Polyarthralgia

Rubella mild infection rash lasts 3 days

Management

• Supportive management

Congenital Rubella 

Infection of the mother in the first trimester can lead to abortion or stillbirth, or to fetal malformation, including congenital heart disease, deafness and blindness (cataract or glaucoma)

Overview Also known 'slapped cheeck' or fifth disease.

Aetiology

• Parovirus B19

Clinical presentation

• School aged
• Very red cheek (slapped cheek appearance)
• Lacy eruption mainly on the extremities
• Arthritis

Erythema infectiosum characteristic slapped cheek appearance

Management

• Supportive management

Complications

• Aplastic anaemia
• Thrombocytopenia and neutropenia neutropenia.
• Parvovirus B19 infection in pregnancy can cause fetal hydrops

Papular Purpuric Gloves and Socks Syndrome is also caused by parvovirus B19 and presents with erythema, oedema, petechaie and purpura of palms and soles + burning and pruritus. It is self limiting and occurs in children and adolescents.

Overview Also known as exanthema Subitum and sixth disease.

Aetiology - Human herpes 6 virus

Clinical presentation

• 6months - 3 years
• Fever ~41C for three days followed by
• Generalised maculopapular rash
  • Circular to elliptical rose red maculopapular rash involving the trunk

High grade fever followed by circular to elliptical rose red maculopapular rash involving the trunk

Complications

• Seizures

Overview Pityriasis Rosea is a self-limiting skin rash thought to be caused by herpesvirus 6 or 7. Herald patch is often the primary lesion followed by additional similar smaller lesions around. Herald patch often misdiagnosed initially as a tinea infection.

Aetiology

• Human herpesvirus 6 or 7

Clinical Presentation

• Herald patch on the trunk may present first
• Smaller similar lesions after

Herald spot (primary lesion) followed by smaller lesion around

Investigation

• Differentiate from tinea (fungal) using KOH

Management

• Resolves spontaneously
• Watchful waiting

Overview Molluscum contagiosum is a common viral skin infection of childhood that causes localised clusters of epidermal  pearly papules with central umbilication

Aetiology

• Poxvirus

Clinical presentation

• Small, pearly papules with central umbilication
• Skin lesions occur on any part of the skin surface
  • Conjunctivitis if around eyelids

Pearly papule with central umbilication

Management

• Supportive treatment - each lesion lasts ~7days
• Deroofing of the lesion with a 21-gauge cutting-edged needle and wiping out the contents.

2 year old infant bought in with vesicular rash on her hand, foot and mouth.

Overview Mild vesicular eruption caused by a Coxsackie A virus.

Aetiology

• Coxsackievirus A16

Clinical presentation

• <10 years old +/- adults
• 1-2 weeks after and URTI
• Ellpitical grayish vesicles, pustules and erosions on hand feet and buttocks

Management

• Supportive care

Complications

• Myocarditis
• Pneumonia
• Encephalitis

A 12 year old boy present with fever sore throat and follicular conjunctivitis

Clinical Presentation

• Fever
• Pharyngitis
• Follicular Conjunctivitis

Differential Diagnosis

• Streptococcus pharyngitis

Investigations

• Viral PCR

Management

• Supportive treatment

Overview Benign epidermal tumors caused by multiple types of human papillomaviruses. The common wart (verruca vulgaris) occurs particularly on hands, knees and elbow.

Aetiology

• Human Papilloma Virus

Clinical Presentation

• Plane or flat warts, 1–3-mm, pink or brown, barely raised papules, occur on the face
• Plantar warts occur particularly over pressure points on the soles and can be differentiated from calluses by a loss of skin markings over the skin surface.
• Anogenital warts may be acquired from maternal infection during delivery but their presence in older children raises the suspicion of sexual abuse

Management depends on type and number of warts, the location on the body, and the age of the patient

• No cure
• Supportive treatment - most resolve themselves
• Salicylic acid with regular paring and occlusion.
• Cryotherapy (topical liquid nitrogen) + salicylic acid

Overview Common, contagious viral infection involving the skin characterised by pruritic vesicles which eventually crust over. Clinical reactivation later in life results in herpes zoster (shingles). It is transmitted by airborne spread.

Aetiology

• Varicella Zoster Virus

Clinical Presentation - all stages of rash is seen

• Prodromal symptoms 1-3 days - fatigue, headache, fever (this is more common in adults)
• Pruritic, erythematous maculopapular rash
• Rash begins in face and spreads to trunk and extremities
• Rash evolves into vesicles with narrow red halo "Dew drops on rose petals"
• Vesicles then crust

Vesicular rash which crust over. The rash presents in all its stages. Person is not contagious once lesions crust.

Management

• Supportive
• Person is infective 2 days before rash appears and when rash crusts over
  • Stay home, no school
• Paracetamol (avoid aspirin)
• Avoid scratching
  • cut fingernails
  • antihistamines
• Antivirals - aciclovir (usually for older children/adults who have severe chicken pox)

Complication

• Secondary bacterial skin infection from scratching
• Can leave pitted scars

Overview Primary Herpes simplex virus (HSV) infection in children is usually asymptomatic or non- specific. Herpetic gingivostomatitis is the most common specific clinical manifestation, occurring in 25% to 30% of cases.

Clinical presentation

• 1-3 years old
• Fever
• Ulcer on gums, tongue and palate
• Dehydration
• Anorexia

Management

• Fluids
• Oral lignocaine gel
• Acyclovir (for those who are immunocompromised)

Complications

• Encephalitis
• Eczema herpeticum
• System HSV infection in neonates

Overview Infectious mononucleosis is a febrile illness caused by the herpes (Epstein– Barr) virus. It can mimic diseases such as HIV primary infection, streptococcal tonsillitis, viral hepatitis and acute lymphatic leukaemia

Aetiology

• Ebstein Barr Virus

Classification

• Febrile
• Anginose
• Glandular

Clinical Presentation

• School age child, adolescents
• Fever
• Pharyngitis
• Fatigue
• Mylagia
• Headache
• Hepatosplenomegaly
• Lymphadenopathy
• Rash is polymorphous - non specific, occurs in about 5% of cases only.
  • Rashes development are almost always related to antibiotics given for tonsillitis
  • The secondary rash is most often precipitated by one of the penicillins, especially ampicillin or amoxycillin.

Differential Diagnosis

• HIV infection
• CMV
• Toxoplasmosis
• Acute streptococcus pharyngitis
• Adenovirus
• Hepatitis
• Lymphoma
• Leukaemia

Investigations

• FBC - Lymphocytosis
• Blood film- atypical lymphocytes.
• Positive Monospot test for heterophil antibody
• Serum EBV-specific antibodies

Management

• NSAIDS
• Aspirin
• Fluids
• Nutrition
• +/- acyclovir
• If airway compromise - ENT review + steroids to decrease oedema

Complications

• Splenic rupture
• Airway obstruction
• Hepatitis
• Rash (ampicillin related)
• Burkitt's lymphoma
• Oral hairy leukoplakia