Flashcards in Paeds 3 - Allergy/Neonates/Development etc Deck (151)
what is impetigo?
highly infectious skin infection - common on face in infants and young children, esp in eczema etc.
caused by staph aureus - rarely can be caused by strep infection
what are the clinical features of impetigo?
erythematous macules develop into honey-crusted lesions.
how is impetigo treated?
topical antibiotics if only mild e.g. mupirocin
if more severe - fluclozacillin.
nasal carriage can cause reinfection - nasal cream containing chlorhexidine and neomycin can be used to eradicate.
what is infantile seborrhoeic eczema and how is it treated?
cradle cap - scaly, non-itchy rash on scalp, might spread.
treatment - emollients and mild topical steroids.
what is atopy?
predisposition to atopic disorders - eczema, asthma and hay fever.
genetic, confers abnormal immune response to environmental allergens. often a lot of FHx.
what are the clinical features of eczema?
dry, red, itchy rash - usually on extensor surfaces and face in infants and young children, and the flexures (inner elbow, back of knees) in older kids.
how is eczema managed?
need to hydrate skin and minimise inflammation.
- general measures - cotton clothing, non-biologic detergents, no parental smoking, pets etc
- emollients - 2-3 times a day, replace soap with aqueous cream.
- mild topical steroid - 1% hydrocortisone ointment/cream applied to affected areas twice daily - highly effective to get under control, then focus on emollients.
- new class - topical immunomodulators e.g. tacrolimus cream
what is Stevens-Johnson syndrome?
widespread erythema multiforme (target lesions ± macules/papules/bullae), often painful. often a drug reaction or infection (herpes simplex, mycoplasma, EBV).
supportive management, pain relief, may need ICU.
what is allergic rhinitis?
hay-fever! also dust, pet allergies. 20% of children will have it.
IgE mediated inflammation from allergen exposure to nasal mucosa - release of inflammatory mediatory from mast cells.
what are the symptoms of allergic rhinitis?
sneezing, pruritus, nasal discharge (bilateral), itchy red eyes.
how do you manage a patient with allergic rhinitis?
antihistamines e.g. loratidine, cetirizine.
intranasal corticosteroid sprays e.g. fluticasone.
describe the pathology behind anaphylaxis
severe allergic reaction with respiratory difficulty (wheeze/obstruction) and/or cardiovascular symptoms (shock, hypotension, dizziness).
prior exposure to antigen-sensitising mast cells and basophils --> systemic release of inflammatory mediators --> capillary leak, mucosal oedema, smooth muscle contraction.
mediated by IgE.
common allergens - food (peanuts), insect venom (rare), latex, drugs (penicillin, vaccines - rare)
what are the symptoms/signs of anaphylaxis?
resp - cough, stridor, hoarseness, facial swelling, wheeze
cario - faint, dizziness, syncope, pallor, tachycardia
may also see uritcaria, GI signs etc - these aren't as life threatening.
describe the management of an anaphylactic reaction
IM adrenaline 150/300/500 micrograms depending on age.
follow with IV or oral steroids and antihistamine - helps prevent protracted reaction.
what is urticaria?
transient, itchy, erythematous rash - raised welts (hives).
induced by mast cell degranulation - histamines etc released causing vasodilation and increased capillary permeability.
mostly due to viral infections, might be an allergy thing.
what is angioedema?
swelling of lips and eyes that sometimes accompanies utricaria
if lips are involve - emergency, tongue may get involved and then there's a risk of respiratory obstruction.
how do you manage urticaria/angioedema?
urticaria - should resolve spontaneously, give antihistamine if itchy, avoid precipitating factors.
angioedema - go to hospital, ABCDE.
what is Henoch-Schonlein purpura?
multisystem vasculitis of small blood vessels.
follow UTRI or exposure to drug or allergen.
think it's immune-mediated - IgA.
what are the clinical features of HSP?
skin - purpuric rash of legs and buttocks
GI - colicky abdo pain ± gross/occult bleeding
joints - pain and swelling of large joints
kidneys - glomerulonephritis - microscopic haematuria
how is HSP diagnosed and managed?
Rx - symptomatic/supportive. recover in 4-6 weeks.
what is achondroplasia?
autosomal dominant disorder - short limbs, large head, abnormal neurology.
gene on chromosome 4, fibroblast growth receptor gene (FGFR3).
what is Fragile X syndrome?
X linked disorder typically involving severe learning impairment, more common in males, associated with autism.
physical features - dysmorphic facial appearance (large forehead, long face, large prominent ears), macrocephaly, macro-orchidism.
briefly explain the genetics of Downs syndrome?
trisomy 21 - extra chromosome can come from non-dysjunction (the chromosome 21 pair fails to separate at meiosis, so one gamete has two copies), translocation or mosaicism (occurs during mitosis after formation of zygote, so some cells might be normal, may have milder phenotype).
risk increases with maternal age.
what are the clinical features of Down syndrome?
dysmorphic facial features - round face, epicanthis folds, flat nasal bridge, protruding tongue, small ears, Brushfield spots on iris.
other dysmorphic features - single palmar creases, flat occiput, incurved little fingers, sandal toe gap, small stature.
structural defects - cardiac defects, duodenal atresia.
neurology - hypotonia, developmental delay, mean IQ = 50
how is Down syndrome diagnosed and managed?
nuchal translucency on antenatal US.
chromosome analysis, FISH is faster.
support and education for parents.
what are the genetics in Turner syndrome?
only 1 normal X chromosome.
affects 1 in 2500 live born females.
might have 45, XO
or deletion of short arm of one X chromosome
some have mosaicism.
what are the clinical features of Turner syndrome?
hallmarks - short stature + primary amenorrhoea.
normal intelligence, specific learning difficulties.
dysmorphic features - neck webbing, widely spaced nipples (shield chest), wide carrying angle, short stature.
structural/functional - gonadal dysgenesis, congenital heart disease, renal anomalies
how is Turner's syndrome identified/diagnosed?
prenatally on USS.
at birth - presence of puffy hands and feet.
in childhood - short stature
in adolescence - primary amenorrhoea.
diagnosis confirmed by peripheral blood karyotype.
how is Turner's syndrome managed?
GH therapy improves final height.
oestrogen therapy at c.11 years to promote secondary sex characteristics.
towards end of puberty, progestogen added to maintain uterine health