Paediatrics 3 Flashcards
What are cavernous haemangioma?
Strawberry birth mark
What are risk factors for children having a strawberry naevus (cavernous haemangioma)?
Female infant, premature, those whose mothers underwent CVS sampling
What is the common sites of strawberry naevus? When might they have complications?
Common sites include the face, scalp and back. Rarely they may be present in the upper respiratory tract leading to potential airway obstruction
Are cavernous haemangioma permanent?
No: most go away by 9 years
What is capillary haemangioma?
Port wine stain; permanent reddish purple birthmark, often on the face
What are mongolian blue spots?
Blue-ish grey marks, commonly on non white babies
What are milia (milk spots)?
Sebaceous plugs: nothing to worry about
What condition might cafe au lait spots be associated with?
Neurofibromatosis 1
What are cafe au lait patches?
Neurofibromas. Skin coloured, raised nodules or papules with a smooth, regular surface
What size and number of neurofibromas can indicate neurofibromatosis?
more than 5, 15mm in diameter
What tumours may be associated with neurofibromas?
Brain tumours, malignant peripheral nerve sheath tumours, GI stroma tumour, spinal cord tumours. Increased risk of many cancers
What is Reye’s syndrome?
Condition that arises from aspirin treatment of viral infections in children.
What is the presentation of Reye’s syndrome?
Abnormal liver function tests, vomiting and encephalopathy
What is molluscum contagiosum?
Viral skin infection caused by the molluscum contagiosum virus
What is the presentation of molluscum contagiosum?
Small, flesh coloured papules that characteristically have a central dimple. Present in crops of multiple lesions in a local area
How is molluscum contagiosum treated?
No treatment, no isolation. Should avoid sharing towels, or other close contact
When does eczema typically present in children?
Before 2 years
What are the features of eczema (including distribution)?
Itchy, red rash. Infants: often face and trunk. Younger children: extensor surfaces. Older children: flexor surfaces and creases of face and neck
What is wet wrapping, and how/when is it done?
Severe childhood eczema. Large amounts of emollient (and sometimes topical steroids) applied under wet bandages
What is eczema herpeticum?
Viral skin infection in patients with eczema, caused by herpes simplex virus or varicella zoster virus
What is the treatment of mild eczema?
Use of mild potency topical corticosteroid with a simple emoillent
What is stevens johnson syndrome?
Severe systemic reaction affecting skin and mucosa, almost always caused by a drug reaction
What can cause stevens-johnson syndrome?
Penicillin, sulphonamides, anti epileptic drugs, allopurinol, NSAIDs, OCP
What is the features of Stevens-Johnson syndrome?
Rash which is typically maculopapular with target lesions. May develop into vesicles or bullae. Nikolsky sign positive in erythematous areas. Mucosal involvement. Systemic features
What percentage of the body is affecting in Stevens-Johnson syndrome and toxic epidermal necrolysis?
Generally, SJS affects less that 10% of body surface area whereas TEN affects more than 10% of body surface area
What is the pathophysiology of Stevens Johnson syndrome and toxic epidermal necrolysis?
Spectrum of the same pathology. Disproportionate immune response causes epidermal necrosis
What is the disease course of Stevens Johnson syndrome?
Prodrome of non specific systemic symptoms (fever, cough, sore throat, sore mouth, sore eyes, itchy skin). Then purple/red rash, spreads across skin and blisters.
Skin breaks away, sheds, leaves raw tissue underneath. This can also happen on mucous membranes
What is the management of stevens johnson syndrome?
Medical emergency. Treatment includes steroids, immunoglobulins, immunosuppressant
What are potential complications of stevens johnson syndrome?
Secondary infection, permanent skin damage, visual complications (due to eye involvement)
What is urticaria?
Hives; small itchy lumps on the skin. Pale pink.
What is the pathophysiology of urticaria (hives)?
Caused by the release of histamine and other pro-inflammatory chemicals by mast cells in the skin
What causes acute/chronic hives?
Acute: allergic reaction
Chronic idiopathic: autoimmune response
What can trigger an acute hives reaction?
Any allergenic sort of things: food, medications, viral infections, insect bites
What is the pathophysiology of chronic urticaria?
Chronic urticaria is an autoimmune condition, where autoantibodies target mast cells and trigger them to release histamines and other chemicals. Causes localised vasodilation and increased capillary permeability
What is the treatment of urticaria?
- non sedating anti histamines are first link (fexofenadine)
- steroids in severe flares
What is angiodema? What condition is it associated with?
A variant of urticaria with significant swelling of subcutaneous tissues (often lips, eyelids, genitals, tongue, larynx)
What are potential complications of severe angioedema?
Can cause acute upper or lower respiratory tract obstruction and may be life threatening
What is the management of angioedema?
Facial oxygen, IM adrenaline, IV hydrocortisone, nebulised salbutamol
What is allergic rhinitis?
An inflammatory disorder of the nose, where the nose becomes sensitised to allergens such as house dust mites, grass, tree, pollens
What are the features of allergic rhinitis?
Sneezing, bilateral nasal obstruction, clear nasal discharge, post nasal drip, nasal pruritus
What is the treatment of allergic rhinitis?
Allergen avoidance and symptom relief (anti histamines, montelukast, intranasal steroids)
What shouldn’t nasal decongestants be used for a long time in allergic rhinitis?
Increasing doses are required to achieve the same affect. Rebound hypertrophy of the nasal mucosa may occur.
What is the most common cause of anaphylaxis in children?
Nuts
What is the definition of anaphylaxis as per the Resus Council UK?
the sudden onset and rapid progression of symptoms: airway, breathing, circulation problems
What ABC symptoms may occur in anaphylaxis?
Airway: swelling of the throat and tongue. Hoarse voice and stridor
Breathing: respiratory wheeze, dyspnoea
Circulation: hypotension, tachycardia
What skin and mucosal changes might be seen in anaphylaxis?
Generalised pruritus, widespread erythematous or urticarial
What dose of adrenaline should be given in <6 month olds?
100-150mg
What dose of adrenaline should be given in 6month- 6 year olds?
150mg
What dose of adrenaline should be given in 6-12 year olds?
300mg
What dose of adrenaline should be given in >12 years?
500mg
How often can adrenaline be given in anaphylaxis?
Every 5 mins
What is refractory anaphylaxis?
Respiratory/cardiovascular problems persisting despite 2 doses of IM adrenaline
What management should be given in refractory anaphylaxis?
IV fluids for shock, consideration of IV adrenaline infusion
What levels can be checked post anaphylaxis to determine if it was a true episode?
Serum mast cell tryptase: remain raised
What can be given to anaphylaxis patients with patients with persisting skin symptoms?
Non sedating oral anti histamines, with preference to chlorphenamine
Why should discharge be careful in anaphylaxis patients?
20% of patients have a biphasic reaction
What type of hypersensitivity reaction is anaphylaxis?
Type 1
What is necrotising fasciitis?
Life threatening deep tissue infection that spreads rapidly
What is the name for necrotising infection of the perineum?
Fournier’s gangrene
What most commonly causes necrotising fasciitis?
Mixed anaerobes and aerobes (often post usrgery in diabetes)
What causes type 2 necrotising fasciitis?
Streptococcus pyogenes
What are risk factors for necrotising fasciitis?
Recent trauma, burns, soft tissue infections, diabetes mellitus (especially if treated with SGLT-2 inhibitors), IV drug use, immunosupresion
What site is most commonly affected by necrotising fasciitis?
Perineum (Fournier’s)
What are the features of necrotising fasciitis?
Acute onset, pain+swelling+erythema at site, rapidly worsening cellulitis with pain out of keeping with physical features, tender over infected tissue. Late signs: skin necrosis, gas gangrene
What is the management of necrotising fasciitis?
Urgent surgical referral for debridement and IV abx
What karotype is associated with Klinefelter’s?
47 XXY
What are the features of Klinefelter’s syndrome?
Tall, lack of secondary sexual characteristics, small firm testes, infertile, gynaecomastia, elevated gonadotrophin levels but low testosterone
How is Klinefelter’s diagnosed?
Karotype (chromosomal analysis)
When do the symptoms of Klinefelters tend to appear?
Puberty
What conditions are those with Klinefelters at increased risk of?
Breast cancer, osteoporosis, diabetes, anxiety and depression
What management can improve quality of life for those with Klinefelters?
Testosterone replacement therapy (can help development of male secondary sexual characteristics)
What is the karotype in Turner syndrome?
45 XO
What are features seen in Turners syndrome?
Short, webbed neck, high arching palate, broad chest with wide nipples, elbow abnormality, primary amenorrhoea
What genetic condition can cause neonatal lymphoedema in the feet?
Turners
What cardiac abnormalities are associated with Turner’s syndrome?
Bicuspid aortic valve, coartication of the aorta
What are the most serious long term health risks for women with Turner’s?
Aortic dilatation and dissection
What type of conditions are patients with Turner’s more at risk of?
Autoimmune: such as autoimmune thyroiditis and Crohn’s
Why are patients with Turner’s shorter than average?
There is underlying skeletal dysplasia. Ovarian dysgenesis and consequent gonadal failure result in loss of pubertal growth spurt
What renal abnormality is seen in patients with Turners?
Horseshoe kidney
What is the management to help with symptoms of Turner’s?
Growth hormone therapy to improve stature, oestrogen and progesterone replacement, fertility treatment
What is the karotype associated with down syndrome?
Trisomy 21(due to non disjunction during maternal oogenesis)
What are the clinical features of Downs?
- Face: upslanting palpebral fissure, epicanthic folds, Brushfield spots in iris, protruding tongue, small low set ears, flat occiput
- single palmar crease
- sandal gap between big and first toe
- hypotonia
- congenital heart issues
- duodenal atresia
- Hirschsprung’s
What are the possible cardiac complications of Down’s syndrome?
- endocardial cushion defect
- ventricular septal defect
- secundum atrial septal defect
- tetralogy of Fallot
- isolated patent ductus arteriosus
What leukaemia is associated with Down’s?
ALL
What are later complications of Down’s syndrome?
Subfertility, short stature, repeated respiratory infections, hypothyroidism, Alzheimer’s, atlantoaxial instability (assess in those who do sports with risk of dislocation), visual issues, deafness
What is the first line test for diagnosis of Down’s syndrome?
Combined test: ultrasound and maternal blood tests
What maternal blood tests are assessed in combined test for Down syndrome?
- b-HCG (higher=greater risk)
- pregnancy associated plasma protein A (PAPPA): lower indicates greater risk
When is the combined test for down’s syndrome performed??
Between 11 and 14 weeks gestation
When is the triple test performed for Downs syndrome?
Between 14 and 20 weeks
What is assessed in the triple test for Down’s?
Beta HCG, alpha feroprotein (lower=greater risk), serum oestriol (lower=greater)
When is the quadruple test for Down’s syndrome performed?
between 14 and 20 weeks
What is assessed in the quadruple test for down syndrome?
beta HCG, alpha fetoprotein, serum oestriol, inhibin-A
What is done if the combined, triple or quadruple test for down syndrome show an increased risk?
amniocentesis or chorionic villus sampling
What is an alternative to invasive testing for Mum’s with higher risk of having a child with down’s syndrome?
NIPT: non invasive prenatal testing. Simple blood test from mother, which will contain some placental tissue and fetal DNA. This is assessed
What routine follow up investigations must be done in patients with down syndrome?
Regular thyroid checks, echocardiogram, regular eye checks, regular audiometry
What karyotype is associated with Edward’s syndrome?
Trisomy 18
What are the key features of Edward’s syndrome?
Micrognathia (small jaw), low set ears, rocker bottom feet, overlapping fingers
What are key complications of Edwards syndrome?
Only a few days life expectany. Heart defects
What karyotype is associated with Patau syndrome?
Trisomy 13
What key features are associated with Patau syndrome?
Microcephalic, small eyes. Cleft lip/palate, polydactyly, scalp lesions.
What genetic syndromes are all women offered screening for?
Edwards, Patau’s, Downs
What is the typical presentation of Fragile X syndrome?
Learning difficulties, macrocephaly, long face, large ears, macro-orchidism
How does Fragile X syndrome typically present?
Delay in speech and language development
Around what age is fragile X diagnosed?
Around 3 years old
What is Kallmann’s syndrome?
Recognised cause of delayed puberty secondary to hypogonadotrophic hypogonadism
How is Kallmann’s inherited?
X linked
What are the features of Kallmann’s syndrome?
Delayed puberty, cryptorchidism, anosmia (no smell/body odour), normal or above average height
What are the features of Angelman syndrome?
Fascination with water, happy demeanour, widely spaced teeth. Delayed development, learning disability, ataxia, inappropriate laughter, epilepsy, ADHD, microcephaly
What is the inheritance/mutation in Angelmans syndrome?
Impaired or absent function of the maternally imprinted UBE3A gene on chromosome 15
What is the key features of. Prader Willi syndrome?
Constant insatiable hunger (leads to obesity), hypotonia as infant, mild-moderate learning disability, hypogonadism, characteristic facial features (almond shaped eyes, narrow forehead, downturned mouth)
What treatment is offered in Prader Willi syndrome? and why?
Growth hormone: improves muscle development and body composition
What is the genetic cause of Prader Willi syndrome?
Chromosome 15, gene imprinting, gene deleted from father
Why is feeding initially difficult in Prader Willi syndrome?
Due to hypotonia, babies are floppy. Weight gain is later
What is the inheritance pattern of Noonan syndrome?
Autosomal dominant
What are the features of Noonan syndrome?
Webbed neck, widely spaced nipples, short stature, pectus carinatum and excavatum, pulmonary stenosis, triangle shaped face, coagulation issues, cryptorchidism
What are the characteristic features of William syndrome?
Sociable personality, starburst eyes (pattern on iris), wide mouth with big smile, small chin, sunken nasal bridge
What are possible complications in William syndrome?
Hypercalcaemia, supravalvular aortic stenosis
What monitoring should be done in William syndrome?
Echocardiogram, blood pressure monitoring (aortic stenosis and HTN). Calcium monitoring
What is the inheritance of marfans?
Autosomal dominant
What protein is mutated in Marfans?
Protein fibrillin-1 (component of connective tissue)
What are the key features of Marfans?
Tall stature, long neck, long linbs, long fingers, high arch palate, hypermobility, pectus carinatum or excavatum, pes planus (flat feet)
What are associated conditions with marfans?
Mostly cardiac: mitral or aortic valve prolapse(Wtih regurgitation), aortic aneurysms, dilation of aortic sinuses pneumothorax, joint dislocations, lens dislocation in the eye
What treatment can be given to prevent complications in Marfans?
Beta blockers, angiotensin II receptor antagonists. Minimise blood pressure and heart rate
What monitoring should be done in Marfans?
Yearly ECHOs and review by opthalmologist
What enzyme is stereotypically raised in muscular dystrophy?
Creatinine kinase
What is the inheritance of Duchennes?
X linked
What is Gower’s sign and what condition is it associated with?
Child has to use arms to stand up from a squatted position; Duchennes
When does Duchennes typically present? And how?
First 4 years of life, delayed motor milestones and mild speech delay
What are the features of Duchennes?
- Gowers sign (weakness of limb girdles)
- calf pseudohypertrophy
- sparing of facial extra-ocular and bulbar muscles
- waddling gait
- particular weakness around pelvis
What are associated conditions with Duchennes?
Dilated cardiomyopathy. There will just be progressive weakness and atrophy of skeletal and heart muscles, which shortens life expectancy
How is Duchennes diagnosed?
Previously muscle biopsy, now genetic
What is muscular dystrophy?
Umbrella term for genetic conditions that cause gradual weakening and wasting of muscles
What treatment may slow progression of Duchennes?
Oral steroids (slow progression of muscle weakness) and creatine supplementation
What is Beckers muscular dystrophy?
Similar to Duchennes, but much less serious
What is myotonic dystrophy?
Form of muscular atrophy with prolonged muscle contractions
What are typical signs of myotonic dystrophy?
Prolonged muscle contractions, progressive weakness, cataracts
What is the first sign of puberty in girls and in boys?
Breast buds in girls, testicular enlargement in boys
What is early and delayed puberty in girls?
Early: <8 years
Delayed: >13 years
What is early and delayed puberty in boys?
Early: <9 years
Delayed: >14 years
What staging is used to determine pubertal stage?
Tanner staging
What is hypogonadotrophic hypogonadism?
Deficiency of LH and FSH, leads to deficiency of testosterone and oestrogen
What is hypergonadotrophic hypogonadism?
A lack of response to LH and FSH by the gonads. No negative feedback from sex hormones, so LH and FSH levels continue to rise
What can cause hypogonadotrophic hypogonaism?
- previous damage to the hypothalamus of pituitary
- growth hormone deficiency
- hypothyroidism
- hyperprolactinaemia
- serious chronic conditions
- excessive exercise or dieting
- Kallman syndrome
What causes hypergonadotrophic hypogonadism?
-previous damage to the gonads (eg, testicular torsion, cancer infections)
- congenital absence of the testes or ovaries
- Kleinfelters
- Turners
What hormonal blood tests should be undertaken if there is delayed puberty?
- early morning serum FSH and LH
- thyroid function tests
- growth hormone testing
- serum prolactin
What are differentials in delayed puberty with a short stature?
Turner’s, Prader-Willi, Noonans
What are differentials for delayed puberty with normal stature?
Polycystic ovarian syndrome, androgen insensitivity, Kallman’s syndrome, Klinefelters syndrome
What is the definition of precocious puberty?
Development of secondary sexual characteristics before 8 years in females and 9 years in males
What is the definition of short stature?
Height more than 2 standard deviations below the average for age and sex
What are possible differential causes for short stature?
- familial short stature
- constitutional delay in growth and development
- malnutrition
- chronic diseases
- endocrine disorders: such as hypothyroidism
- genetic conditions such as down syndrome
- skeletal dysplasia
What is constitutional delay in growth and puberty?
Considered a variation of normal development; leads to short stature in childhood, but normal in adulthood. Ultimately, normal adult height is reached
What is a key feature of constitutional delay in growth and puberty and how is it assessed?
Delayed bone age; assess via xray images of wrists, and looking at growth plates
What are the two types of precocious puberty?
- Gonadotrophin dependent (central/true): due to premature activation of HPA axis, FSH and LH raised
- Gonadotrophin independent (pseudo/false): due. to excess sex hormones, LH and FSH low
What is the general variation in causes of precocious puberty in boys and girls?
Girls: more likely idiopathic central, and boys: more likely a organic cause such as intracranial tumours
How can testes indicate the causes of precocious puberty?
- bilateral enlargement: gonadotrophin release from intracranial lesion
- unilateral enlargement: gonadal tumour
- small testes: adrenal cause (tumour or adrenal hyperplasia)
What are causes of peipheral precocious puberty (gonadotrophin independent)?
- gonadal: ovarian tumour, testicular tumour, McCune-Albright syndrome
- adrenal: congenital adrenal hyperplasia, adrenal tumour
- HCG secreting tumours
- iatrogenic (exogenus sex steroid administration)
How can central precocious puberty be stopped?
Suppression of HPA axis with long acting GnRH analogue (downregulates LH and FSH secretion)
What is McCune Albright syndrome?
Genetic condition that affects bones, skin, endocrine system. Leads. to cafe au lait skin pigmentation, scar tissue forming on bones, and endocrine glander hyperfunction (with the ovary being most affected)
What is the inheritance of androgen insensitivity syndrome?
X linked recessive condition
What is the pathophysiology of androgen insensitivity syndrome?
End organ resistance to testosterone causing genetically male children (46XY) to have a female phenotype
What are the features of androgen insensitivity syndrome?
‘primary amenorrhoea’, little or no axillary and pubic hair, undescended testes causing groin swellings, breast development
Why might breast development occur in androgen insensitivity syndrome?
Due to conversion of testosterone to oestradiol in the testis and peripheral tissue
How is androgen insensitivity syndrome diagnosed?
Buccal smear or chromosomal analysis
What is the management of Androgen insensitivity syndrome?
- counselling: raise child as female
- bilateral orchidectomy
- oestrogen therapy
What should be excluded in any female presenting with an inguinal hernia?
AIS
What are LH and testosterone levels in Klinefelter’s syndrome?
High LH, low testosterone
What are LH and testosterone levels in Kallman’s syndrome?
Low LH, low testosterone
What are LH levels and testosterone levels in androgen insensitivity syndrome?
High LH, normal/high testosterone
What are LH levels and testosterone levels in testosterone secreting tumours?
Low LH, high testosterone
What is a risk factor for undescended testis?
Pre-term
What are possible complications of undescended testis?
Infertility, torsion, testicular cancer, psychological
What is the treatment timeline for a unilateral undescended testis?
Referral made from around 3 months, see a urological surgeon before 6 months
What is the treatment timeline for bilateral undescended testes?
Reviewed by a senior paediatrician within 24 hours
What are the two types of undescended testes, and which are associated with more risk?
Palpable undescended testes, and impalpable testes (more risk, as associated with malignant degeneration)
What is the chosen investigation for impalpable testes?
Laproscopy (ultrasound, CT, MRI are not helpful)
What should be immediately excluded for a child with acute scrotal pain?
Testicular torsion
What are the features of testicular torsion?
Pain is usually severe, sudden onset, can be refferred to lower abdomen, nausea and vomiting. Examination: swollen, tender testis retracted upwards, reddened skin
What reflex is lost in testicular torsion?
Cremasteric (when inner thigh stroked, ipsilateral testicle doesn’t retract)
What is Prehn’s sign, and what conditions can it differentiate?
Whether elevation of the testis can ease the pain: yes in epididymitis, no in testicular torsion
What is the treatment of testicular torsion?
Urgent surgical exploration. If there is a torted testis, then both testis should be fixed to reduce risk in the future
What causes testicular torsion?
Abnormally mobile mesentery of the testis inside the tunica vaginalis: anomly is usually bilateral and allows the gonad to twist on its vascular pedicle
What are the differential diagnosis of aucte scrotal pain?
Testicular torsion, torted hydatid, epididymo-orchitis, testicular trama, idiopathic scrotal oedema
What is the likely diagnosis if a girl has not started her periods but suffers cyclical pain?
Imperforate hymen
What is primary amenorrhoea?
Absence of periods at 15 years old
What levels would you expect to see of anti mullerian inhibiting factor in women with Turner’s syndrome?
Low: reflects ovarian reserves. In Turner’s syndrome, the ovaries are insufficient
What murmur is often seen in Turners syndrome?
Ejection systolic
Why might someone with Turners present with a raised blood pressure?
Due to undetected coartication of the aorta
What is premature thelarche?
Premature breast development; differentiated from premature puberty as no other associated symptoms. Investigation not usually required, will resolve
What is the commonest cause of hypothyroidism in children?
Autoimmune thyroiditis
What are long term complications of hypothyroidism in children?
Thyroid hormone is essential for the development and functioning of the brain and body. Undiagnosed hypothyroidism can lead to significant problems with neurodevelopment and intellectual disability
What is congenital hypothyroidism?
When a child is born with an underactive thyroid gland
What are the two types of congenital hypothyroidism?
Dysgenesis (underdeveloped thyroid gland) and dyshormonogenesis (fully developed gland that doesn’t produce enough hormone)
How is congenital hypothyroidism diagnosed?
Newborn blood spot screening test
What are the features of congenital hypothyroidism
Prolonged neonatal jaundice, poor feeding, constipation, increased sleeping, reduced activity, slow growth and development, hypotonia, dry skin, umbilical hernias, large fontanel
What is autoimmune thyroiditis?
Autoimmune inflammation of the thyroid gland, subequently leading to underactivity of the gland
What antibodies are seen in Hashimoto’s thyroiditis?
Antithyroid peroxidase (anti-TPO) antibodies and antithyroglobulin antibodies
What conditions are associated with acquired hypothyroidism?
Type 1 diabetes and coeliac disease
What is the investigations of Hashimotos thyroiditis?
Full thyroid function blood tests (high TSH, low T4/3), thyroid ultrasound, thyroid antibodies
What is the treatment of Hashimoto’s thyroiditis?
Levothyroxine
What is the most common cause of hypothyroidism in children in the developing world?
Iodine deficiency
What hormones do the adrenal glands produce?
Cortisol, aldosterone, adrenaline, noradrenaline
What causes congenital adrenal hyperplasia?
Congenital deficiency of the 21-hydroxylase enzyme
What is the inheritance pattern of congenital adrenal hyperplasia?
Autosomal recessive
What is the action of aldosterone?
Increases sodium reabsorption into the blood, increases potassium secretion into urine
Why does congenital adrenal hyperplasia cause high testosterone levels?
The conversion of progesterone to testosterone does not rely on the 21-hydroxylase enzyme. The excess progesterone therefore converts to testosterone, as this is the only way it can get used up
What are the levels of hormones seen in CAH?
Low aldosterone, low cortisol, high testosterone
Why is aldosterone and cortisol low in CAH?
Low 21-hydroxylase, which is responsible for converting progesterone into aldosterone and cortisol
How do female patients with CAH typically present at birth?
Virilised genitalia (ambiguous) and an enlarged clitoris due to high testosterone levels
What electrolyte and glucose abnormalities are seen in CAH?
Hyponatraemia, hyperkalaemia, hypoglycaemia
How do children with severe CAH tend to present?
Poor feeding, vomiting, dehydration, arrhythmias
Why do patients with CAH have skin hyperpigmentation?
Anterior pituitary gland response to low levels of cortisol by producing increasing amounts of ACTH. A byproduct of ACTH is melanocyte simulating hormone, which increases melanin within skin cells
How do patients with less severe CAH typically present?
Symptoms tend to present due to high androgen levels. So females will be tall for age, facial age, absent periods, deep voice, early puberty. Boys will be tall, deep voice, large penis
what is the management of CAH?
Cortisol replacement, aldosterone replacement
What is Addisons disease?
Adrenal glands have been damaged leading to reduced cortisol and aldosterone
What is Addisons disease also called, and commonly caused by?
Primary adrenal insufficiency and autoimmune
What causes secondary adrenal insufficiency?
Inadequate ACTH stimulating the adrenal glands, leading to low cortisol. Due to loss or damage to the pituitary, or congenital underdevelopment
What causes tertiary adrenal insufficiency?
Inadequate CRH release by the hypothalamus, typically due to long term oral steroids which suppress the hypothalamus
What are the features of adrenal insufficiency in babies?
Lethargy, vomiting, poor feeding, hypoglycaemia, jaundice, failure to thrive
What investigations should be done in adrenal insufficiency?
U and Es (hyponatraemia, hyperkalaemia), hypoglycaemia. Check cortisol, ACTH, aldosterone, renin
What hormone levels are seen in Addisons?
Low cortisol, high ACTH, low aldosterone, high renin
What hormone levels are seen in secondary adrenal insufficiency?
Low cortisol, low ACTH, normal aldosterone, normal renin
How is adrenal insufficiency diagnosed?
Short synacthen test (synthetic ACTH given: should stimulate cortisol production. If no production indicates Addisons)
How is adrenal insufficiency treated?
Hydrocortisone (replace cortisol), fludrocortisone (replace aldosterone)
Why might steroid doses need to be changed for adrenal insufficiency patients in acute illness?
There is an increased demand on the body for steroids to cope with illness. Might need to increase dosage
What is Addisonian crisis?
an acute presentation of severe Addisons, where the absence of steroid hormones result in a life threatening presentation
What is the presentation of Addisonian crisis?
Reduced consciousness, hypotension, hypoglycaemia, hyponatraemia, hyperkalaemia
What can trigger Addisonian crisis?
Steroid withdrawal, infection, trauma, acute illnesses, sepsis, first presentation of Addisons
What is the treatment of Addisons?
IV hydrocortisone, IV fluids (with or without glucose)
How is IGF-1 produced, and what is its function?
Anterior pituitary gland produces growth hormone, which stimulates growth and cell reproduction. Also stimulates release of IGF-1
How is growth hormone insufficiency diagnosed?
Growth hormone stimulation tests involve measuring the response to medications that normally stimulate the release of growth hormone. Examples of these medications include glucagon, insulin, arginine and clonidine. Growth hormone levels are monitored regularly for 2-4 hours after administering the medication to assess the hormonal response. In growth hormone deficiency there will be a poor response to stimulation
What are causes of obesity in children? (organic)
Growth hormone deficiency, hypothyroidism, downs, cushings, prader willi
How does growth hormone deficiency cause obesity?
Reduces lipolysis, which can exacerbate obesity
What are indications for an oral glucose tolerance test in obese children?
Severe obesity (BMI >98th centile), acanthosis nigricans, positive FHx of T2DM, ethnic origin increasing risk, PCOS, HTN
What should normal fasting blood glucose be below?
6 mmol/L
What fasting glucose implies impaired fasting glucose, and what implies diabetes?
IFG: 6-7
DM: >7
What viruses can trigger T1DM?
Coxsackie B virus and enterovirus
How does T1DM lead to hyperglycaemia?
Pancreas stops producing insulin, so the cells of the body can’t take glucose from the body, and use it for fuel. Cells cannot use glucose, so level keeps rising in the blood, leading to hyperglycaemia
What levels should blood glucose ideally be between?
4.4 and 6.1
Where is insulin produced?
By the pancreas, by beta cells in the islets of langerhans.
How does insulin reduce blood sugar?
Causes cells to absorb glucose from the blood and use it as fuel. Also causes muscle and liver cells to absorb glucose from the blood and store it as glycogen. Without insulin, cells can’t take up and use glucose
Where is glucagon produced?
Alpha cells of the islets of Langerhans in the pancreas
What is the role of glucagon?
Increases blood sugar levels; glycogenolysis (break down glycogen to glucose), and gluconeogenesis (convert proteins and fats to glucose)
What is ketogenesis and when does it offucr?
The liver takes fatty acids and converts them to ketones. Occurs when there is a insufficient supply of glucose, glycogen stores are exhausted.
What percentage of new type 1 diabetic children present in DKA?
25-50%
What is the cassic triad of hyperglycaemia?
Polyuria, polydipsia, weight loss
Why might HbA1c not be useful for a diagnosis of t1DM?
Average of 3 months: may not reflect a recent rapid rise
What is C-peptide?
Based on blood sugar level; sign the body is producing insulin. Low amounts in type 1
How can c-peptide differentiate type 1and 2 diabetes?
type 1: c peptide is low
type 2: c peptide is raised
What autoantibodies can be found in type 1 diabetes?
anti-GAD, islet cell antibodies, insulin autoantibodies
What glucose levels indicate diabetes?
> 7 (fasting), >11.1 random
What is a possible side effect of injecting insulin into the same spot repeatedly?
Lipodystrophy: subcutaneous fat hardens and prevents normal absorption of insulin
What forms can insulin be given in?
- insulin pump
- background, long acting insulin (basal)
- short acting, 30 minutes before meals (bolus)
What can cause hypoglycaemia in patients with T1DM?
too much insulin, not enough carbohydrates or not processing the carbohydrates properly, for example in malabsorption, diarrhoea and vomiting and sepsis.
What are typical symptoms of hypoglycaemia?
Hunger, sweating, tremour, irritability, dizziness, pallor. Can also lead to reduced consciousness, coma, death
How should mild hydoglycaemia be treated?
Combination of rapid acting gluose (such as lucozade) and slower acting carbohydrates
What is the treatment of severe hypoglycaemia?
IV dextrose, IM glucagon
What are possible causes of hypoglycaemia other than diabetes?
Hypothyroidism, glycogen storage disorders, growth hormone deficiency, liver cirrhosis, alcohol
How can chronic hyperglycaemia affect the body in the long term?
Can cause damage to endothelial cells of blood vessels; leads to leaky, malfunctioning vessels that can’t regenerate. High levels of sugar can also lead to suppression of the immune system
What are macrovascular complications of T1DM?
Coronary artery disease (major cause of death), peripheral ischaemia (ulcers, poor wound healing, diabetic foot), stroke, hypertension
What are microvascular complications of T1DM?
Peripheral neuropathy, retinopathy, kidney disease
How is T1DM monitored?
- HbA1c (every 3 to 6 months, check long term control)
- capillary blood glucose
- flash glucose monitoring
What is first line management of hypertension in diabetes?
ACE-I or angiotensin-II receptor antagnists due to renoprotective effects
What are the most common precipitating factors of DKA?
Infection, missed insulin, MI
What are the diagnostic criteria of DKA?
- glucose >11 or known DM
- pH <7.3
- bicarbonate <15
- ketones >3 mmol/l, or ketonuria
What is the presentation of DKA?
Abdominal pain, polyuria, polydipsia, dehydration, Kassmaul respiration (deep hyperventiltion), acetone smelling breath
Upon treatment, what time should ketonaemia and acidosis have resolved within?
24 hours
What complication are children at risk of in DKA?
Cerebral oedema
What is the physiology of ketoacidosis and bicarbonate production?
When the cells in the body have no fuel and think they are starving, they initiate the process of ketogenesis so they have a usable fuel. Over time the glucose and ketone levels get higher and higher. Initially the kidneys produce bicarbonate to buffer the ketone acids in the blood and maintain a normal pH. Over time the ketone acids use up the bicarbonate and the blood starts to become acidic. This is called ketoacidosis.
How does DKA lead to dehydration?
Hyperglycaemia overwhelms the kidneys and glucose starts being filtered into the urine. The glucose in the urine draws water out with it in a process called osmotic diuresis. This causes the patient to urinate a lot (polyuria). This results in severe dehydration. The dehydration stimulates the thirst centre
Howdoes potassium imbalance occur in DKA?
Insulin usually drives potassium into cells, so in DKA serum potassium is high, but body potassium is low because no potassium is in the cells. This can lead to hypokalaemia
What are the aspects of DKA that will kill the patient?
Dehydration, potassium imbalance and acidosis
Why does cerebral oedema occur following DKA correction?
In DKA, dehydration and hyperglycaemia cause water to move to the extracellular space, which causes the brain to shrink. If DKA rapidly corrected, there will be a rapid move of water from the extracellular space to the intracellular. Leads to brain oedema
What are features of cerebral oedema in patients being treated for DKA?
Headache, altered behaviour, bradycardia, loss of consiousness
What are the management options for cerebral oedema in DKA?
Slowing IV fluids, IV mannitol, IV hypertonic saline
What are the main principles of DKA management
- Fluid replacement (isotonic saline)
- Insulin (0.1 unit/kg/hour). Once blood glucose <14 mmol/l infusion of 10% dextrose should be started in additional to NaCl regime. Stop short acting insulin, only long acting
- Potassium infusion (potassium quickly driven into cells)
When do symptoms of hypoglycaemia develop?
<3.5 mmol/L
What potassium replacement should be used in DKA?
40 mmol/l
Why might children with CAH have raised 17-hydroxyprogesterone
This is the precursor of 21-hydroxylase, so builds up
What is the monitoring recommended in type 1 diabetes mellitus?
At least 4 times a day, including before each meal and before bed
What medication can patients with type 1 DM and a BMI >25 have alongside insulin
metformin
