Paediatric Dermatology Flashcards
Urticaria (hives) - state the following:
- Pathophysiology
- Presentation (including any red flags)
- Management
Pathophysiology:
- Superficial swelling of the skin, leading to a red, raised, itchy rash
- Caused by release of histamine from mast cells, in response to a trigger
- Can be acute or chronic, localised or widespread
Presentation:
- Migratory, well-circumscribed, erythematous plaques on the skin surface
- Itchy
- Usually describe a trigger e.g. allergy, insect bite
Red flags - consider anaphylaxis e.g. facial swelling, SOB etc.
Management:
- Avoidance of triggers
- Non-sedating antihistamine e.g. Fexofenadine or Cetirizine
- If severe, short course of an oral corticosteroids
State some differentials for an acute rash (non-specific, viral, bacterial, other)
Non-specific:
- Viral exanthem
- Heat rash
- Urticaria
- Eczema
- Cellulitis
Viral:
- Chicken pox
- Measles
- Rubella
- Roseola
- Parvovirus B19
- Pityriasis rosea
- Hand, foot and mouth disease
Bacterial:
- MENINGITIS
- Scarlet fever
- Impetigo
- Staphylococcal scalded skin syndrome (SSSS)
Other:
- Erythema multiforme
- Eczema herpetiform
- Kawasaki disease
- Scabies
- Ringworm
Which symptoms and questions should you ask about for a patient presenting with an acute rash
Rash:
- When did it start
- Where on the body did it start and progression since
- Any triggers
- Fever
- Malaise
- Headache / visual disturbance / neck stiffness
- Loss of appetite
- Abdominal pain
- Irritability
- Myalgia / arthralgia
Questions:
- Up to date on immunisations?
- Any unwell contacts
- New medications
State some causes of acute urticaria and chronic urticaria
Acute (< 6 weeks):
- Allergy e.g. food, pets, medication
- Contact e.g. stinging nettles, latex
- Viral infection
- Insect bite
Chronic (>6 weeks):
- Chronic idiopathic with no clear trigger
- Chronic inducible with triggers e.g. strong emotions, exercise, weather change, sunlight, pressure Dermographia
- Autoimmune associated e.g. SLE
State some differential diagnoses for urticaria
Erythema multiforme minor
Contact dermatitis
Atopic eczema
Chronic pruritus
Pemphigoid (bullous) and dermatitis herpetiformis
Polymorphic eruption of pregnancy
Urticaria pigmentosa
Urticarial vasculitis
When might you consider referring to a specialist for a patient with urticaria
- Painful and persistent (suspect vasculitic urticaria).
- Symptoms are not well controlled on antihistamine treatment
- Angio-oedema and no wheals, that do not respond to first-line treatment
- Chronic inducible urticaria, difficult to manage in primary care
Able to prescribe monoclonal antibodies
State the six red rashes (viral exanthems)
First disease: measles
Second disease: scarlett fever (strep A)
Third disease: rubella (german measles)
Fourth disease: Ritter’s disease (staphylococcal scalded skin syndrome)
Fifth disease: parvovirus B19 (slapped cheek syndrome)
Sixth disease: roseola infantum
Measles - state the following:
- Pathophysiology
- Presentation (including any red flags)
- Investigations
- Management
Pathophysiology:
- Caused by Measles morbillivirus
- Extremely contagious
- Incubation period of up to 2 weeks
- Normally would be covered by the MMR vaccine
Presentation:
- Incubation period of up to 2 weeks
- Prodromal period with fever, cough, coryza, conjunctivitis and Koplik spots
- Widespread maculopapular rash, 3-5 days after fever which starts behind the ears and spreads cranio-caudally
Red flags
- SOB
- Uncontrolled fever
- Convulsions
- Altered consciousness
Investigations:
- 3-14 days after rash use measles-specific antibody testing
- 1-3 days after rash use RNA PCR
Management:
NOTIFIABLE DISEASE
Generally self-limiting & no specific antiviral treatment
- Maintain hydration
- Analgesia
- Antipyrexics
- Treat secondary opportunistic infections
- Vitamin A if < 2 years old
State some complications of measles if untreated
Most common:
- Diarrhoea and dehydration
- Pneumonia
- Acute otitis media
Less common:
- Meningitis / encephalitis
- Hearing / vision loss
- Death
State some advice you could give to parents if child has measles
- Stay away from nursery / school / work for at least 4 days after the initial development of the rash (ideally until full recovery)
- Avoid contact with vulnerable people e.g. unvaccinated, pregnant, immunocompromised
Safety net for:
- SOB
- Uncontrolled fever
- Convulsions
- Altered consciousness
Contact dermatitis - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Skin reaction caused by an external agent
- Can either be irritant (non-immunological) or allergic (immunological), and acute or chronic
- Very common, especially work related irritant contact dermatitis, can be from acute mild irritants e.g. water, soaps, solvents or from more toxic substances e.g. acids
Presentation:
Generally well defined areas where contact has occurred
- Pruritus
- Burning
- Erythema
Acute
- Swelling and blistering
Chronic
- Hyperpigmentation, fissuring, and scaling
Investigations:
- Patch testing for allergic contact dermatitis
- Irritant contact dermatitis is a diagnosis of exclusion if patch testing is negative
Management:
Irritant
- Washing off the irritant
- Thick emollient protection
- Avoidance of future exposure
Allergic
- Low potency topical corticosteroid e.g. Hydrocortisone 2.5%
- Avoidance of allergen
Human papillomavirus (HPV) - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Very common virus group, more than 100 different types of HPV
- Leads to cutaneous warts (infection of keratinocytes with HPV)
- Most common STI, 90% cases resolve within 2 years with no complications
- Spreads via close contact during sexual contact, vaginally, orally or anally, or sharing sex toys
Presentation:
Usually asymptomatic
- Sometimes painless lumps in genital area
Investigations:
- HPV test during cervical screen
- May screen for in sexual health clinics with MSM (higher risk)
Management:
- No treatment
- Treat complications such as genital warts or cervical cell changes
- Consider treating cutaneous warts if painful, cosmetically unsightly, persistent or personal request
- Treatment options (non-facial) e.g. topical salicylic acid, cryotherapy or both
Suggest when you would refer to secondary care for management of cutaneous warts
- Facial wart
- Extensive warts
- Uncertain diagnosis / suspicious diagnosis
- Multiple persistent warts and compromised immunity
Hand, foot and mouth disease - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Characteristic rash caused by Coxsackie A virus
Presentation:
Incubation period 3-5 days, followed by 1-2 days of URTI symptoms e.g. sore throat, dry cough, fever
- Painful mouth ulcers = key feature
- Followed by widespread blistering red spots, most on hands feet and around mouth
- Rash may be itchy
Investigations:
- Clinical appearance of rash
Management:
No treatment! Supportive care
- Adequate fluid intake
- Analgesia
Rash and illness should resolve after 7-10 days
HIGHLY CONTAGIOUS - avoid sharing bedding and careful with dirty nappies
Erythema multiforme - state the following:
- Pathophysiology
- Presentation
- Investigations
- Management
Pathophysiology:
- Hypersensitivity reaction, resulting in an erythematous rash
- 2 main causes are viral infections and medications
- Specifically, herpes simplex virus and mycoplasma pneumoniae
Presentation:
- Widespread, itchy erythematous rash
- Target lesions
- Sore mouth (stomatitis)
- Flu-like symptoms e.g. headache, myalgia
Investigations:
Important to identify underlying cause
Generally clinical decision based on appearance if clear cause e.g. cold sores
- If unsure of underlying cause, may do chest x-ray for mycoplasma pneumoniae
Management:
Generally supportive if clear underlying cause, should resolve in 1-4 weeks
- Severe cases may require hospital admission, IV fluids, analgesia and steroids, antibiotics/antiviral if infection present
