Paediatric Dermatology Flashcards
What are the acute causes of skin rashes?
Infection
Allergy
Skin irritation
What are the chronic causes of skin rashes?
Chronic conditions of other systems
Neurocutaneous syndromes
What are some important factors when taking a paediatric rash history?
- is the child ill/febrile?
- SQITARS type questions
- exposure to insects or possible allergens?
- recurrence?
- itching?
- contact with others with a rash?
What is desquamation?
Loss of epidermal cells causing a scaly eruption
What conditions can cause desquamation?
Scarlet fever (post) Kawasaki’s disease
What are papules?
Solid palpable projections from the skins surface
What is a maculopapular rash?
Mixed rash with macules and papules, which tend to be confluent
When can children develop a maculopapular rash?
With measles, or as a reaction to a drug
What are vesicles?
Raised, fluid-filled lesions under half a cm in diameter
What are large vesicles called? I.e. over 0.5cm diameter
Bullae
When can children develop a vesicular rash?
In chickenpox
What is the difference between purpura and petechiae?
Size - Petechiae are tiny purpura.
What are purpura/petechiae?
Purple lesions that do not fade on pressure.
Small haemorrhages under the skin.
When can children get petechiae/purpura?
Meningococcaemia
ITP
HSP
Leukaemia
What are wheals?
Raised lesions with a flat top and pale centre.
When can children develop a wheal rash?
With urticaria/hives
What are macules?
Flat pink lesions
When can a child develop a macular rash?
With rubella, roseola, or as a café-au-lait spot
What vascular birthmarks can we see in children?
Capillary haemangioma
Capillary malformation
Mongolian blue spot
What is a capillary haemangioma?
A bright red lumpy lesion due to proliferation of blood vessels
How common are capillary haemangiomas?
Very common, especially in preterm infants
What do we do for capillary haemangiomas?
Nothing as they often regress spontaneously after the age of 4.
Can treat with injected steroids if near important structures.
What does a capillary malformation look like?
Sharply circumscribed, pink to purple lesion
How common are capillary malformations?
3 in 1000 births will have them
What is the pathophysiology underlying capillary malformation vascular birthmarks?
Normal dermal capillaries are abnormally dilated
A mother is concerned that her newborn has some funny marks on their head.
O/E - marks are located on back of the head and across the forehead. Pink naevus which is flush with the skin. He is otherwise well.
What should you tell the mother?
It is a stork-bite mark/Naevus simplex.
Very common birth mark, which will either fade or be covered by hair.
No Rx needed.
A mother is concerned that her newborn has some funny marks on their head.
O/E - pearly white vesicles/papules across the cheeks, eyelids, and chest. She is otherwise well.
What should you tell the mother?
This is milia.
Very common, affects ~50% of babies.
Clears spontaneously after a few weeks.
What is milia?
Retention of keratin and sebaceous materials in sweat glands that haven’t formed fully yet.
A mother is concerned that her newborn has some funny marks on their face. He also has a fever.
O/E you find a bright erythematous rash across the cheeks, sparing the nose, eyes, and mouth.
What else would you find out from the history?
Child had a fever for ~1 week before rash appeared.
In an older infant, they may complain pf muscle aches and headache. Younger pts may have signs of these.
A mother is concerned that her newborn has some funny marks on their face. He also has a fever.
O/E you find a bright erythematous rash across the cheeks, sparing the nose, eyes, and mouth.
What could you tell mum?
This is “slapped-cheek syndrome”, Fifth disease, or Erythema infectiosum.
Caused by parvovirus B19.
Rash may spread to extensor surfaces before resolving.
Can use antipyrexials for supportive management if fever is bothering child.
A first time mother brings in her infant, who has developed a rash 1 day ago.
What elements of the history do you need?
Fever?
Has the rash changed/developed?
Anyone else at home/nursery/school been affected?
Safetynet for complications.
What complications would you want to screen/safetynet for with a child with chickenpox?
Secondary bacterial infections.
Encephalitis
A first time mother brings in her infant, who has developed a rash 1 day ago.
O/E the rash is vesicular, present across the face and torso. Each vesicle has an erythematous halo. A few lesions have crusted over with a central umbilication.
What do you tell mum?
This is chickenpox caused by VZV/HHV3.
Very contagious - should stay home from school for 5 days after last new lesion appears.
Inform school.
Can use calamine lotion to help with itching. Try not to scratch, and keep nails short to prevent scarring.
How can secondary bacterial infections of chickenpox be recognised?
New or persistent high temperature.
What can secondary bacterial infections of chickenpox lead to if untreated?
Toxic shock syndrome
Necrotising fasciitis
A 10 year old girl is brought in with a fever and a rash.
She also has a sore throat and headache.
O/E the rash is fine, erythematous, rough textured, and is maculopapular. Her cheeks are flushed and her tongue has a strawberry appearance.
What do you tell the parent?
This is scarlet fever - caused by group A beta haemolytic strep.
Rash will last a few days, then fade and skin begins to peel.
N specific Rx, just supportive.
What is the technical term for peeling skin after a rash?
Desquamation
A child is brought in with a fever and a rash.
On taking the hx you find the parents didn’t fully vaccinate their child. What are you concerned about now?
The rash being caused by a preventable disease such as measles, mumps, or rubella.
What is erythema multiforme?
A skin condition that occurs due to a hypersensitivity reaction to infections or drugs.
What does erythema multiforme look like?
Iris or target lesions, although other forms (hence multiforme) do occur.
What infections can cause erythema multiforme?
HSV 1 +2
Mycoplasma paneumonia infections
Fungal infections
Other viruses (VZV, CMV, Hep C, HIV)
What drugs can cause erythema multiforme?
Barbiturates Penicillins Anticonvulsants NSAIDs Vaccinations
What history might someone with a widespread target like rash present with?
No prodrome A new medication Mild URTI Cold sores Mild itching/burning skin
How should erythema multiforme be managed?
- If caused by drug, withdraw the drug
- Antivirals if due to HSV
- Systemic - analgesi, mouthwash, skin care as appropriate.
How long does it usually take erythema multiforme to resolve?
3-5 weeks
What is seborrhoeic dermatitis?
A common benign scaling rash that affects areas rich in sebaceous glands (face, scalp, and chest).
It is an inflammed form of dandruff.
Who does seborrhoeic dermatitis affect?
Anyone from puberty onwards.
If it occurs in babies it is called infantile seborrhoeic dermatitis.
What might make seborrhoeic dermatitis worsen?
Illness Stress Fatigue Change of season Poor immune function Certain medications
How should scalp seborrhoeic dermatitis be managed?
Remove thick crusts with olive oil/salicylic acid/coal tar
Medicated shampoos used twice a week for a month or more
Topical steroids can reduce itching
How should face/ears/chest/back seborrhoeic dermatitis be managed?
Clean skin but avoid soap.
Antifungal cream e.g. ketoconazole
1% hydrocortisone
Pimecrolimus/tacrolimus ointment
