Silent Thyroiditis Case Flashcards
What are some physical exam maneuvers you should do when evaluating the thyroid?1
- palpation of neck for mass, nodularity, thyromegaly or thrill
- Listen to the neck for a thyroid bruit
- Reflexes
- Vitals - bradycardia with hypotension or tachycardia with hypertension?
- Weight - increase or decrease?
- body temp - low?
- Facial appearance - loss of hair? puffiness?
- Eyes - exopthalmos? lid lag?
- Hair growth patterns
- Skin - palmar erythema? diaphoresis? dry or pale? myxedema?
- Hands and nails - onycholysis? swollen fingers?
- Tremor? shaky hands? hyperkinetic?
- facial expression - dull? slow movement? slow speech? hoarseness?
- Listen to heart - arrhytmias?
When would you hear a thyroid bruit?
typically with graves disease or anythign that causes a big thyroid (the extra blood flow can be heard - very hypervascular)
When would you see hyperreflexia? hyporeflexia?
hyper in hyperthyroid
hypo in hypothyroid
What would the vitals look like in hypothyroid?
bradycardic with hypotension
also might see low temperature
In which would you expect to see puffy eyelids?
hypoT
In which would you expect to see exopthalmos and lid lag?
lid lag in hyperT
exopthalmos is specific to graves
In which would you see hair loss?
both
just thinning in hyperT
coarse, brittle, strawlike with diffuse alopecia and lateral eyebrow loss in hypoT
What skin findings would you expect in hyperT?
palmar erythema and diaphoresis
What skin findings would you expect to see in hypoT?
dry wtih slight palor
pretibial myxedema
What would you espect on the hand and nail exam in hyperT?
onycholysis and swollen fingers (acropachy)
Which would you expect to see tremor in?
hyperthyroid
Which one would you expect to see hoarseness in?
hypoT - because of myxedema in the throat
What’s the most common thyroid blood test?
the TSH
If the TSH is elevated, it’s ____
hypothyroidism (over 3)
If the TSH is low, it’s___
hyperthyroidism (under 0.3)
What does free T4 measure?
it measure the free T4 that’s floating around in the blood
it will be elevated in hyperthyroidism and low in hypothyroidism (usually)
Which gives you a better sense of actual T4 - the free T4 or total T4?
you would think it would be total, but it’s actually free
this is because the free T4 is what’s available for uptake and use by the cells. Bound levels may not be immediately available and is more affected by other drugs, illness and physical changes like pregnancy.
So what does total T4 actually give you a sense of?
how much binding protein a patient is making (since 99% of the hormone is bound)
Simiarly, which do we care more about - gree T3 or total T3
free
What does the free thyroxine index tell us?
it tells us how much T4 is free compared to bound.
this can help tell if abnormal amounts of T4 are present because of abnormal amounts of thyroxine-binding globulin
Thyroglobulin levels can be low or normal with normal thyroid function, but when can it be elevated?
thyroiditis, Graves disease, or thyroid cancer
When do we most commonly monitor the thyroglobulin level?
when we’re evaluating the effectiveness of treatment for thyroid cancer and to monitor for thyroid cancer recurrence
When are thyroid peroxidase antibodies most often present?
in hashimotos disease and less commonly in other forms of thyroiditis
THyroglobulin antibodies are present in ___% of hashimoto patients and __%of graves patients
60% of hashimotos
30% of graves
If you have already been diagnosed with graves, a high level of anti-thyroglobulin antibodies are indicative of what?
more likely to eventually become hypothyroid
Anti-TSH receptor antibodies are seen in what?
graves disease (rarely hashimotos)
In Graves disease, the radioactive iodine uptake is ____
high (because it’s hyperthyroid)
In Hashimoto’s thyroiditis, the radioactive iodine uptake is ____
generally low with patchy hot spots in the gland
How do we tell is a nodule is hot or cold?
hot will have increased radioactive iodine uptake while cold will have low
A ___ nodule is rarely cancerous
hot
What percentage of cold nodules are cancerous?
only 10-20%
What is thyroid US used for?
evaluation of nodules, lumps and enlargement
Can a US determine if a nodule is malignant?
nope - can only tell you if it’s fluid filled or solid tissue
What would be some US findings suspicious for cancer?
size over 10 mm, micro-calcifications, hypoechoic, hypervascular, irregular margins, height greater than width?
If the US is concerning, what is the next step?
Do a fine need aspiration of the nodule
If you have high TSH and low FT4, what’s the diagnosi?
primary hypothyroidism
High TSH, High T4?
secondary hyperthyroidism
High TSH and normal T4?
subclinical hypothyroidism
If TSH is low and T4 is low, what’s the diagnosis?
secondary hypothyroidism (rare)
If TSH is low and T4 is high?
hyperthyroidism or thyrotoxicosis
If TSH is low but T4 is normal?
sublinical hyperthyroidism
What kind of thyroiditis occurs in the postpartum window?
silent thyroiditis
Does silent thyroiditis cause a thyrotoxicosis or hypothyroidism?
can do either - usually thyrotoxicosis first and then hypothyroidism later
What is the cause of silent thyroiditis?
not sure - probably autoimmune since you can find anti-thyroid peroxidase and anti-thyroglobulin antibodies
How common is silent thyroiditis in the US?
higher than you think - 5-10%
Who is at increased risk for developing postpartum thyroiditis?
any women with: autoimmune disorders those with positive anti-thyroid antibodies hx of previous thyroid dysfunction Hx of previous postpartum thyroiditis family hx of thyroid dysfunction
What percentage of women will have a recurrence of silent thyroidis with subsequent pregnancies?
20%
What is the typical timeline for silent thyroiditis?
THe thyrotoxic phase occurs 1-4 months after delivery and lasts for about 1-3 months
the hypothyroid phase typically occurs 4-8 months after the delivery and can last up to 9-12 months
most women return to their normal thyroid function within 12-18 months after the onset of symptoms, but approximately 20% that go into the hypothyroid phase will remain hypothyroid
In which phase do women usually present? Why?
Usually present in the hypothyroid phase
this is because the hyperthyroid symptoms (anxiety, insomnia, palpitations, fatigue, weight loss and irritability) are attributed to being post-partum with the stress of having a new baby
Describe the treatment plan for silent thyroidits?
depends on the stage
for the thyrotoxicosis - use beta blockers (if not nursing) for symptoms, but don’t use thyroid suppressants
for the hypothyroid - try hormoen replacement and continue for about 6-12 months. then taper to see if they can stop taking it. only 20% will need to go back on.
When does postpartum depression usually start?
1-3 weeks after delivery
requires treatment!
What are the postpartum baby blues?
mother feels upset,d epressed and anxious 2-3 days after birth
go away without treatment!
What is postpartum psychosis?
a much more severe verions of postpartum depression - often in women who have bipolar disorders or schizophrenia
