Infectious Rashes in Paediatrics

This article provides an overview of common paediatric rashes, including appearance, causes, relevant investigations and management.

Meningococcal rash

A meningococcal rash is a sign of meningococcal disease.

• Cause: Neisseria meningitidis
• Appearance: non-blanching purpuric or petechial rash. All children presenting with this assumed to have meningococcus until proven otherwise.
• Other symptoms: pyrexia, malaise, meningitis (20-30%)
• Management: immediate admission to hospital, resuscitation and administration of broad-spectrum antibiotics
• Complications: septicaemia, meningitis

For more information, see the Geeky Medics guide to meningitis. 

Steven-Johnsons syndrome / toxic epidermal necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, acute, and potentially fatal skin reactions that cause sheet-like skin detachment and mucosal loss.

• Causes: drugs, chemicals (burns), infections, systemic illnesses
• Appearance: widespread blisters/bullae over erythematous/macular/haemorrhagic skin. Can also have haemorrhagic erosions on mucus membranes. 
• Progression: blisters start on the face before spreading to other areas
• Associated symptoms: fever, arthralgia, myalgia, conjunctivitis, pneumonitis
• Management: supportive (hydration/maintain airway), identify and remove causative agent, dermatology and critical care input

For more information, see the Geeky Medics guide to Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

Impetigo

Impetigo is a superficial bacterial infection affecting the skin, most commonly in young children. 

• Cause: Staphylococcal aureus or streptococcal skin infection
• Appearance: erythematous macules (may progress to be vesicular/bullous) on face, neck or hands
• Epidemiology: infants and young children
• Management: topical (fusidic acid, mupirocin) or systemic (flucloxacillin or clarithromycin)

Kawasaki disease

Kawasaki disease is an acute systemic vasculitis that affects young children.

• Cause: autoimmune-mediated (medium-sized blood vessel vasculitis)
• Symptoms: fever > 5 days, conjunctivitis, polymorphous exanthem, fissuring of lips, strawberry tongue (Figure 4), diffuse erythema of oral and pharyngeal mucosa, periungual desquamation of fingers and toes, erythema of palms and soles
• Other features: arthralgia, septic meningitis, coronary artery aneurysm, vasculitis and other cardiac conditions (congestive heart failure, myocarditis, arrhythmias, mitral insufficiency, acute MI)
• Investigations: echocardiography (needs follow up 6 weeks later), inflammatory markers (ESR and CRP), alpha-1 antitrypsin
• Management: high dose intravenous immunoglobulin, aspirin

For more information, see the Geeky Medics guide to Kawasaki disease.

Staphylococcal scalded skin syndrome

Staphylococcal scalded skin syndrome is a blistering skin disease caused by the exfoliate staphylococcal toxin.

• Cause: exfoliative staphylococcal toxin
• Appearance: blistering initially, then desquamation affecting flexural areas, buttocks, hands, or feet
• Epidemiology: typically occurs in children under three years old
• Associated symptoms: fever, irritability, diffuse blanching erythema around the mouth, desquamation as above, positive Nikolsky’s sign (the epidermal layer easily sloughs off when pressure is applied)
• Management: hospital admission, supportive care, analgesia and intravenous antibiotics (flucloxacillin is first-line)

Eczema herpeticum

Eczema herpeticum is a complication of atopic eczema that occurs with infection of the herpes simplex virus (HSV).

• Cause: type I HSV co-infection with active atopic eczema
• Primary infection: in pre-school children, presenting with a sore throat, pyrexia, stomatitis, vesicles or ulceration in the oral cavity and face
• Secondary infection: a cluster of itchy and painful blisters on the face and neck. New blisters have umbilication, old blisters crust and form sores.
• Management: oral acyclovir, systemic antibiotics for secondary bacterial infection

Erythema nodosum

• Appearance: red or violet subcutaneous nodules located pretibially
• Causes: streptococcal pharyngitis, idiopathic, sarcoidosis, primary tuberculosis, inflammatory bowel disease, drug reactions
• Management: usually self-limiting or resolves with the treatment of the underlying disorder

Erythema multiforme

Erythema multiforme (EM) is a type IV hypersensitivity reaction that presents with a skin rash.

It is typically triggered by an infection (most commonly herpes simplex virus), however, it can also develop secondary drug reactions. EM typically affects those aged between 20 to 40.

• Causes: HSV (90%), mycoplasma pneumonia, medications, autoimmune disease, sarcoidosis
• Appearance: target-like lesions on the skin. Progresses to erosions of bullae which can involve oral, genital or mucosal areas.
• Management: usually self-limiting, aciclovir is used to treat HSV infections. Oral antihistamines and corticosteroids can be used to reduce pruritus.

For more information, see the Geeky Medics guide to erythema multiforme. 

Measles

Measles is an infectious disease caused by a morbillivirus of the paramyxovirus family.

• Appearance: maculopapular rash lasts 6-8 days
• Associated symptoms: fever, coryza, cough, non-purulent conjunctivitis, Koplik spots
• Epidemiology: young children with a seasonal peak in late winter/spring
• Treatment: supportive, can give antibiotics to prevent secondary infection
• Prevention: MMR vaccine at 18 months

Glandular fever (infectious mononucleosis)

Glandular fever (also called infectious mononucleosis) is an acute viral infection caused by the Epstein-Barr virus (EBV).

• Cause: Epstein-Barr virus
• Associated symptoms: fever, fatigue, sore throat, lymphadenopathy 

A maculopapular rash can occur due to being treated with penicillin whilst infected with EBV (Figure 11). 

Hand, foot and mouth disease

Hand, foot and mouth disease is an acute viral infection caused by enteroviruses (commonly coxsackieviruses). 

• Causes: coxsackievirus A16 and enterovirus A71
• Appearance: oral vesicles which rupture to form ulcers on tongue and buccal mucosa (enanthem). Macular, maculopapular or vesicular exanthema on hands, feet, buttocks, legs, arms.
• Management: supportive, but children with complications may require hospitalization

Erythema infectiosum (fifth disease)

Erythema infectiosum (fifth disease), also called ‘slapped cheek syndrome, is a self-limiting viral infection caused by parvovirus B19. 

• Cause: parvovirus B19
• Symptoms: begins with fever, coryza, headache, nausea and vomiting
• Appearance: malar rash with circumoral pallor (slapped cheek rash), then a lace-like rash on trunk and extremities follows
• Epidemiology: outbreaks among school-aged children
• Treatment: supportive as the virus is self-limiting

Chickenpox (varicella-zoster)

Chickenpox is a common viral infection, caused by the varicella-zoster virus (VZV).

• Appearance: starts on head and trunk, then spreads throughout the body. Red macules -> papules -> pustule-> crusting
• Epidemiology: between 1 and 6 years, seasonal peaks in winter and spring
• Associated symptoms: headache, anorexia, upper respiratory tract infection, fever, itching
• Treatment: antihistamines, paracetamol, acyclovir, VZIG for prophylaxis for contact at-risk individual

For more information, see the Geeky Medics guide to chickenpox.

Nappy (napkin) rash

Nappy rash is an irritant contact dermatitis that occurs in the nappy area. Secondary infection with Candida albicans or bacteria (Staphylococcal aureus or streptococcus) can occur.

• Cause: candida albicans in skin creases. Candida secondarily infects areas of irritant dermatitis that has been left untreated for more than 3 days.
• Appearance: beefy red plaques, satellite papules, superficial pustules
• Treatment: frequent application of emollients, topical antifungal agent (e.g. nystatin, clotrimazole or ketoconazole)

Scabies

Scabies is a highly contagious skin infestation caused by a parasitic mite. It is spread by close contact and is more common among disadvantaged populations.

• Cause: an infestation of the skin by mite Sarcoptes scabiei resulting in a pruritic eruption
• Appearance: small, erythematous papule with haemorrhagic crusts on fingers, elbows, axillary folds, thighs, genitalia, feet
• Treatment: hygiene advice, topical permethrin, oral ivermectin

For more information, see the Geeky Medics guide to scabies. 

Tinea corporis

Tinea corporis (also called ringworm) is a dermatophyte (fungal) infection of the body. 

• Causes: Trichophyton tubrum, Microsporum canis, Epidermophyton
• Appearance: pruritic, circular, erythematous scaly patch spreading centrifugally. Central clearing is seen.
• Treatment: daily application of topical antifungals. Systemic therapy indicated in patients with failed topical therapy (terbinafine, fluconazole or itraconazole).

Tinea capitis

Tinea capitis is a fungal (dermatophyte) infection of the scalp. 

• Appearance: well-demarcated scaly lesion, can be “grey patch”, “black dot” and favus
• Treatment: systemic treatment with oral griseofulvin/terbinafine

Molluscum contagiosum

Molluscum contagiosum is a contagious dermatological infection that predominantly affects children.

• Cause: Poxvirus
• Appearance: flesh-coloured, dome-shaped papules on the skin
• Associated symptoms: usually painless and sometimes pruritic
• Treatment: self-resolving after approximately 18 months 

For more information, see the Geeky Medics guide to molluscum contagiosum.

References

1. James Heilman, MD. Vasculitis / purpura. License: [CC-BY-SA]. Available from: [LINK]
2. Dr. Thomas Habif. Steven Johnson Syndrome. License: [CC-BY-SA]. Available from: [LINK]
3. Asa Thorn. Impetigo. License: [CC-BY-SA] Available from: [LINK]
4. Dong Soo Kim. Strawberry tongue. License: [CC-BY]. Available from: [LINK]
5. OpenStax Microbiology. OSC Microbio 21 02 SSSS.  License: [CC-BY]. Available from: [LINK]
6. Oladokun R et al. Atlas of Paediatric HIV infection. Adapted by Geeky Medics. Licence: [CC-BY-SA].
7. James Heilman, MD. Erythema nodosum. License: [CC-BY-SA]. Available from: [LINK]
8. James Heilman, MD. Erythema multiforme. License: [CC-BY-SA] Available from: [LINK]
9. CDC Public Health Image Library. Measles skin rash. License: [Public domain]
10. Oladokun R et al. Atlas of Paediatric HIV infection. Adapted by Geeky Medics. Licence: [CC-BY-SA].
11. Matibot. EBV penicillin rash. Licence: [CC-BY-SA]. Available from: [LINK]
12. KlatschmohnAcker. Hand foot and mouth disease. Licence: [CC-BY-SA]. Available from: [LINK]
13. Andrew Kerr. Fifth Disease. License: [Public domain]. Available from: [LINK]
14. Lucyin. Chickenpox. Licence: [CC-BY-SA]. Available from: [LINK]
15. Grook da oger. Adapted by Geeky Medics. Licence: [CC-BY-SA]
16. James Heilman, MD. Scabies Nodules. Licence: [CC BY-SA].
17. Fhgd (Own work). Tinea Corporis. Licence: [CC-BY-SA]. 
18. Oladokun R et al. Atlas of Paediatric HIV infection. Adapted by Geeky Medics. Licence: [CC-BY-SA]
19. Grook da oger. Tinea Capitis. Licence: [CC-BY-SA]. 
20. Evanherk. Molluscum contagiosum. Licence: [CC-BY-SA]. 
21. Oladokun R et al. Atlas of Paediatric HIV infection. Adapted by Geeky Medics. Licence: [CC-BY-SA]