THYROIDITIS

Question 1

what is thyroiditis?

Answer 1

general term that refers to “inflammation of the thyroid gland”

Question 2

what are the 2 main etiologies of thyroiditis?

Answer 2

1. autoimmune thyroiditis (hashimoto thyroiditis)
2. painful subacute thyroiditis

Question 3

what is hashimoto thyroiditis?

Answer 3

aka chronic lymphocytic thyroiditis
most common form of thyroiditis
it is an autoimmune thyroid disease resulting in destruction and failure of thyroid glans

Question 4

whats the epidemiology of hashimotos thyroiditis?

Answer 4

age of onset between 30-50
more common in females
exact trigger unknown although genetic and environmental factors play a role

Question 5

what genetic mutation (risk factor) is associated with hashimoto thyroiditis?

Answer 5

mutation in HLA-DR3 and DR5 genes

Question 6

hashimoto thyroiditis has increased incidence in patients with what other 2 disease states (risk factor)?

Answer 6

downs syndrome
turners syndrome

Question 7

what suggest genetic susceptibility of hashimoto thyroiditis (Risk)?

Answer 7

disease clusters found in families suggest genetic susceptibility

Question 8

what is the first step in hashimoto thyroiditis pathogenesis?

Answer 8

autoimmune destruction is initiated; progressive depletion of thyroid epithelial cells

Question 9

what is the second step in hashimoto thyroiditis pathogenesis?

and what mediated this step?

Answer 9

thyroid cell destruction mediated by:
1. CD8+ cytotoxic cells
2. local production of cytokines:

Question 10

what is the third step in hashimoto thyroiditis pathogenesis?

Answer 10

antibodies made to thyroglobulin (tg) and thyroid peroxidase (tpo)

Question 11

what is the 4th step in hashimoto thyroiditis pathogenesis?

Answer 11

lymphocytic infiltration and fibrosis of thyroid cells -> follicles are disrupted and released of stored thyroid hormones:
1. transient increase of thyroxine T4 and
triidothyronine T3
2. compensatory decrease thyroid-stim hormone follows… T3/T4 stores gradually decline
3. end result: increase in TSH+ hypothyroidism (often permanent)

Question 12

with hypothyroidism what are you at an increased risk of having?

Answer 12

1. developing other autoimmune diseases
2. b-cell lymphoma of thyroid gland d/t chronic inflammation

Question 13

what is the triphasic clinical course of hypothyroidism?

Answer 13

1. hashitoxicosis- initial transient hyperthyroidism
2. subclinical hypothyroidism
3. overt hypothyroidism

Question 14

what are the common signs of hypothyroidism?

not talking about cold intolerance

Answer 14

• +/- goiter
• dry, coarse skin; alopecia; cool extremities
• puffy face, hands and feet (nonpitting edema/myxedema), bradycardia

Question 15

hypothyroidism common symptoms:

Answer 15

• hoarse voice, impaired hearing
• constipation
• difficult concentrating/ poor memory
• fatigue, cold intolerance, weight gain
• hair loss, dry skin
• paresthesia
• menstrual irregularities (menorrhagia then oligomenorrhea or amenorrhea)

Question 16

what are the thyroid levels in hashitoxicosis phase?

Answer 16

low TSH + increased T3/T4

Question 17

what are the thyroid levels in subclinical hypothyroidism phase?

Answer 17

increased TSH and normal T3/T4

Question 18

what are the thyroid levels in overt hypothyroidism phase?

Answer 18

increased TSH + decreased T3/T4

Question 19

what other level is increased in 90% of hypothyroidism cases and is a good diagnostic indicator?

Answer 19

increased TPO (thyroid peroxidase)

high TPO levels predict progression to symptomatic hypothyroidism

Question 20

what level is increased in 40% of hypothyroidism cases?

Answer 20

thyroglobulin antibodies

Question 21

what is an incredible diagnostic test for hypothyroidism?

Answer 21

thyroid US
- helps to differentiate between thyroiditis, multinodular goiter, thyroid nodules, or malignancy

Question 22

radioactive iodine uptake diagnostic test (RAI U) is an important test. if there is low uptake what does this mean?

Answer 22

cold thyroid

Question 23

when would you do a FNA?

Answer 23

when there is a dominant nodule or suspicion of malignancy

Question 24

what is the purpose of a thyroid uptake scan?

Answer 24

it is a radiologic diagnostic tool used to determine the thyroid fxn and pathology

Question 25

what does a thyroid uptake scan use?

Answer 25

radioactive iodine

Question 26

what does a graves disease thyroid uptake scan look like?

Answer 26

diffuse increased uptake in both thyroid lobes -looks hella black because shit ton uptake

Question 27

what does a toxic goiter look like on a thyroid uptake scan?

Answer 27

“hot” and “cold” areas of uneven uptake

Question 28

what does a toxic adenoma look like on a thyroid uptake scan?

Answer 28

increased uptake in the single nodule with suppression of surrounding thyroid

Question 29

what does thyroiditis look like on a thyroid uptake scan?

Answer 29

decreased or absent uptake (all grey)

Question 30

what is hashitoxicosis treatment?

Answer 30

1. antithyroid medication should NOT BE USED
2. non-specific beta-blockers to block peripheral conversion of T4 to T3

Question 31

what is overt hypothyroidism treatment?

Answer 31

1. levothyroxine- synthetic form of T4 thats peripherally converted to T3
   
   • 1.6 mcg or 25 mcg in the elderly
   • adj. dose by 12.5 or 25 mcg every 4-6 weeks until clinically euthroid; can also reduce goiter size
   • Goal: TSH of 1-2

Question 32

how do you treat a patient with elevated TPO ab levels and subclinical hypothyroidism?

Answer 32

1. levothyroxine 25-50 mcg PO daily
   
   • adj. dose by 12.5 or 25 mcg every 4-6 weeks until clinically euthroid

Question 33

what does painful subacute thyroiditis often follow?

Answer 33

a URI-> triggers inflammatory destruction of thyroid follicles

Question 33

what is painful subacute thyroiditis?

Answer 33

transient thyrotoxic state characterized by anterior neck pain

Question 34

what do 1/3 of patients who don’t recvoer from painful subacute thyroiditis turn into?

Answer 34

overt hypothyroidism over a 10- year period

Question 35

what is the initial clinical presentation of painful subacute thyroiditis?

Answer 35

1. neck pain in the area of the thyroid (cardinal feature) that may radiate to the jaw
2. diffuse thyroid enlargement (goiter)
3. dysphagia
4. increased sweating
5. tremors/ weight loss
6. fever/tachycardia
   (notice how all there are hyperthyroid sx)

Question 36

what are the characteristics of the thyrotoxic phase of painful subacute thyroiditis?

Answer 36

lasts 4-8 weeks
decreased TSH
initially increase in T4/T3 9T4>T3- transient hyperthyroidism is d/t passive release of stored thyroid hormone
increased ESR and CRP
thyroid scan with radioactive iodine uptake shows low iodine uptake

Question 37

what are the characteristics of the hypothyroid phase?

Answer 37

variable length
increased TSH and decreased T4 and T3

Question 38

in most cases, what is the thyroid able to do as far as “treatment”?

Answer 38

it is able to spontaneously resume normal thyroid production after some months in most cases

Question 39

whats the tx option for patients with significant hyperthyroid symptoms?

Answer 39

beta blockers

Question 40

in patients who have clear signs of hypothyroidism or are symptomatic, what is the treatment?

Answer 40

thyroid hormone supplementation (levothyroxine)

Question 41

what is the tx for relief of thyroid pain?

Answer 41

first line: aspirin 2600 mcg/ day; ibuprofen 3200 mcg/day

Question 42

if there is no improvement of neck pain after 4 days or patient has severe neck pain what is the tx?

Answer 42

corticosteroids 40 mg/ x5-7 days then slowly tapered over 30 days