Endocrinology
Seán Keenan
2022
,Hyperthyroidism
Description
Excessive circulating T3/T4 hormones due to increase in release of preformed thyroid hormones.
Hyperthyroidism in General
Presentation Investigations
- Classic: Heat intolerance; Palpitations; Anxiety - TFTs: See below
- Exam: Sweat; Tremor; ↓ Weight loss - Antibodies: Anti-TPO; Anti-TSH; Anti-Thyroglob.
- Other: Arrythmia; Oligomenorrhoea; Diarrhoea - Nuclear Scintigraphy: Shows ↑ activity zones
Causes - General: AF; Bone Profile Osteoporosis
- Common: Graves’ Disease Management
- Nodular: Toxic Multinodular Goitre - Propranolol: Sx relief such as with tremor
- Tumour: Toxic Adenoma - Carbimazole: Blocks TPO; SE Agranulocytosis
- Subclinical: ↔T4 + ↔ T3 + ↓ TSH - Propylthiouracil: Blocks T4➔ T3 conversion
- Transient: Subacute (de Quervain’s); Hashimoto’s - Block + Replace: Carbimazole + Thyroxine (later)
- Iatrogenic: Amiodarone (also cx hypothyroidism) - Surgical: Resect if required and replace
Graves’ Disease
Presentation Causes
- Thyroid Eye: Exophthalmos; Ophthalmoplegia - Auto-AB: Test for autoantibodies
- Specific: Eye signs; Pretibial myxoedema; Acropachy Management
Causes - Radioiodine Treatment
- Anti-TSH: Autoantibodies act as agonist (90 %) o Replace: Typically require thyroxine in 5 yrs
- Anti-TPO: TPO Iodinates thyroglobulin (75 %) o Risks: Can worsen Ophthalmoplegia
Toxic Multinodular (Plummer’s) Goitre
Presentation Investigations
- Specific: Multinodular goitre - Nuclear Scintigraphy: Patchy uptake (hot spots)
Causes Management
- ↓ Iodine: Thyroid hyperplasia ➔ Mutation ↑ activity - Radioiodine: Therapy of choice
Toxic Thyroid Adenoma
Description Investigations
- Tumour: Benign tumour found on the gland - Monitor: Size + USS + Needle aspiration biopsy
Presentation Management
- Specific: Warm (active) solitary mass (adenoma) - Surgery: Resected if necessary
Thyrotoxic Storm
Presentation Management
- GI: Cholestatic Jaundice; Diarrhoea - Fluids: IV Fluids and electrolyte replacement
- Cardiac: Ectopics; ↑ HR; High Output HF (reversible) - Carbimazole: Lugol’s Iodine after for replacement
Causes - Hydrocortisone: Corrects adrenal axis dysfunction
- Hyperthyroidism: All hyperthyroidism pathologies - Propranolol: Eases HR and corrects symptoms
- Acute phase: Subacute (de Quervain’s); Hashimoto’s Complications
- Iatrogenic: Levothyroxine OD; Thyroid surgery - Pregnancy: Foetal brain malformations
- Other: Infection; Dehydration; Radio-iodine - Cardiac: Congestive HF; MI
,Thyroid Eye Disease
Description Management
- Incidence: Affects 25-50 % of Grave’s Disease - General: Topical lubricants can help dry eyes
- Path: AID leads to retro-orbital inflammation - Other: Steroids; RT; Surgery
Presentation - Prevention: Smoking cessation (↑↑risk factor)
- Key: Exophthalmos; Ophthalmoplegia ; Dry eyes - Monitoring: Refer to ophthalmology if sx serious
- Other: Conjunctival oedema; Optic disc swelling Cautions
- NB: May present with Eu-; Hypo-; Hyper-thyroidism - CI: Radio-iodine can worsen symptoms
Thyroidectomy
Complications Management
- Palsy: Recurrent laryngeal n. palsy ➔ Dysphonia - Palsy: Vocal cord exercises
- Bleed: Haematoma ➔ Respiratory failure - Bleed: Emergency; Remove stitches to ↓ pressure
- Parathyroid: Hypoparathyroidism ➔ ↓ Ca2+ - Parathyroid: See hypoparathyroidism notes
, Hypothyroidism
Description
Deficiency of circulating thyroid hormones; Myxoedema is a severe form of the syndrome and usually applies to cases
in which deposition of mucinous substances results in thickening of skin and subcutaneous tissues. Note that in
untreated hypothyroidism Thyroid Stimulating Hormone (TSH) will increase due to an increase release of Thyrotropin
Releasing Hormone in response to a lack of Thyroid hormone. TRH also leads to an increase in prolactin in 30 % of
cases leading to hyperprolactinaemia symptoms.
Hypothyroidism in General
Presentation Investigations
- Classic: ↑ Weight; Lethargy; Cold intolerance - TFTs: See table below
- Exam: Anhidrosis; Thin hair; Loss of lateral eyebrow Management
- Other: Constipation; Menorrhagia; ↓ Reflexes; CTS - Levothyroxine: Start low in elderly and IHD pt
- ↑ PRL: Amenorrhoea; Galactorrhoea; Gynaecomastia - Monitor: Recheck TFTs 8-12 wk post-dose change
Causes - NB: ↑ T4 + ↑ TSH indicates poor compliance
- Common: Hashimoto’s Thyroiditis - Goal: Normalisation of TSH levels (0.5-2.5)
- Transient: Subacute (de Quervain’s) Thyroiditis - Pregnancy: ↑ Dose by 25-50 mcg
- Dietary: Iodine deficiency - Fe2+ + CaCO3: ↓ Levothyroxine (give 4 hrs apart)
- Rare: Riedel Thyroiditis Complications
- Iatrogenic: Thyroidectomy; Radio-iodine - Treatment: ↑ IHD; AF; Osteoporosis
- Drug: Lithium; Amiodarone; Carbimazole - Congenital: See below
- Associated: Down’s; Turner’s; Coeliac disease - SIADH: Chronic hypothyroidism can ↑ ADH
Hashimoto’s Thyroiditis
Description Investigations
- Incidence: 10x more common in women - Hist: Ashkenazi/Hurtle cells on biopsy
Presentation Management
- Specific: Firm, non-tender goitre - Levothyroxine: Replacement therapy
- Transient: May have acute phase of hyperthyroidism Complications
Causes - MALT: Hashimoto’s is associated with ↑ risk
- Auto-ABs: Anti-TPO; Anti-Thyroglobulin - AID: Coeliac; T1DM; Vitiligo
- Associations: Coeliac; T1DM; Vitiligo
Subacute (de Quervain’s) Thyroiditis
Presentation Investigations
- Phase 1: Hyperthyroidism; Painful goitre; ↑ ESR - Thyroid Scintigraphy: Globally ↓ uptake of I131
- Phase 2: Euthyroid Management
- Phase 3: Hypothyroidism - Supportive: Self-limiting and requires no mx
- Phase 4: Thyroid Fxn and Structure normalises - Pain: Aspirin or NSAIDs
Causes - Steroids: Used for severe cases
- Viral: Thought to be caused following a viral infx
Seán Keenan
2022
,Hyperthyroidism
Description
Excessive circulating T3/T4 hormones due to increase in release of preformed thyroid hormones.
Hyperthyroidism in General
Presentation Investigations
- Classic: Heat intolerance; Palpitations; Anxiety - TFTs: See below
- Exam: Sweat; Tremor; ↓ Weight loss - Antibodies: Anti-TPO; Anti-TSH; Anti-Thyroglob.
- Other: Arrythmia; Oligomenorrhoea; Diarrhoea - Nuclear Scintigraphy: Shows ↑ activity zones
Causes - General: AF; Bone Profile Osteoporosis
- Common: Graves’ Disease Management
- Nodular: Toxic Multinodular Goitre - Propranolol: Sx relief such as with tremor
- Tumour: Toxic Adenoma - Carbimazole: Blocks TPO; SE Agranulocytosis
- Subclinical: ↔T4 + ↔ T3 + ↓ TSH - Propylthiouracil: Blocks T4➔ T3 conversion
- Transient: Subacute (de Quervain’s); Hashimoto’s - Block + Replace: Carbimazole + Thyroxine (later)
- Iatrogenic: Amiodarone (also cx hypothyroidism) - Surgical: Resect if required and replace
Graves’ Disease
Presentation Causes
- Thyroid Eye: Exophthalmos; Ophthalmoplegia - Auto-AB: Test for autoantibodies
- Specific: Eye signs; Pretibial myxoedema; Acropachy Management
Causes - Radioiodine Treatment
- Anti-TSH: Autoantibodies act as agonist (90 %) o Replace: Typically require thyroxine in 5 yrs
- Anti-TPO: TPO Iodinates thyroglobulin (75 %) o Risks: Can worsen Ophthalmoplegia
Toxic Multinodular (Plummer’s) Goitre
Presentation Investigations
- Specific: Multinodular goitre - Nuclear Scintigraphy: Patchy uptake (hot spots)
Causes Management
- ↓ Iodine: Thyroid hyperplasia ➔ Mutation ↑ activity - Radioiodine: Therapy of choice
Toxic Thyroid Adenoma
Description Investigations
- Tumour: Benign tumour found on the gland - Monitor: Size + USS + Needle aspiration biopsy
Presentation Management
- Specific: Warm (active) solitary mass (adenoma) - Surgery: Resected if necessary
Thyrotoxic Storm
Presentation Management
- GI: Cholestatic Jaundice; Diarrhoea - Fluids: IV Fluids and electrolyte replacement
- Cardiac: Ectopics; ↑ HR; High Output HF (reversible) - Carbimazole: Lugol’s Iodine after for replacement
Causes - Hydrocortisone: Corrects adrenal axis dysfunction
- Hyperthyroidism: All hyperthyroidism pathologies - Propranolol: Eases HR and corrects symptoms
- Acute phase: Subacute (de Quervain’s); Hashimoto’s Complications
- Iatrogenic: Levothyroxine OD; Thyroid surgery - Pregnancy: Foetal brain malformations
- Other: Infection; Dehydration; Radio-iodine - Cardiac: Congestive HF; MI
,Thyroid Eye Disease
Description Management
- Incidence: Affects 25-50 % of Grave’s Disease - General: Topical lubricants can help dry eyes
- Path: AID leads to retro-orbital inflammation - Other: Steroids; RT; Surgery
Presentation - Prevention: Smoking cessation (↑↑risk factor)
- Key: Exophthalmos; Ophthalmoplegia ; Dry eyes - Monitoring: Refer to ophthalmology if sx serious
- Other: Conjunctival oedema; Optic disc swelling Cautions
- NB: May present with Eu-; Hypo-; Hyper-thyroidism - CI: Radio-iodine can worsen symptoms
Thyroidectomy
Complications Management
- Palsy: Recurrent laryngeal n. palsy ➔ Dysphonia - Palsy: Vocal cord exercises
- Bleed: Haematoma ➔ Respiratory failure - Bleed: Emergency; Remove stitches to ↓ pressure
- Parathyroid: Hypoparathyroidism ➔ ↓ Ca2+ - Parathyroid: See hypoparathyroidism notes
, Hypothyroidism
Description
Deficiency of circulating thyroid hormones; Myxoedema is a severe form of the syndrome and usually applies to cases
in which deposition of mucinous substances results in thickening of skin and subcutaneous tissues. Note that in
untreated hypothyroidism Thyroid Stimulating Hormone (TSH) will increase due to an increase release of Thyrotropin
Releasing Hormone in response to a lack of Thyroid hormone. TRH also leads to an increase in prolactin in 30 % of
cases leading to hyperprolactinaemia symptoms.
Hypothyroidism in General
Presentation Investigations
- Classic: ↑ Weight; Lethargy; Cold intolerance - TFTs: See table below
- Exam: Anhidrosis; Thin hair; Loss of lateral eyebrow Management
- Other: Constipation; Menorrhagia; ↓ Reflexes; CTS - Levothyroxine: Start low in elderly and IHD pt
- ↑ PRL: Amenorrhoea; Galactorrhoea; Gynaecomastia - Monitor: Recheck TFTs 8-12 wk post-dose change
Causes - NB: ↑ T4 + ↑ TSH indicates poor compliance
- Common: Hashimoto’s Thyroiditis - Goal: Normalisation of TSH levels (0.5-2.5)
- Transient: Subacute (de Quervain’s) Thyroiditis - Pregnancy: ↑ Dose by 25-50 mcg
- Dietary: Iodine deficiency - Fe2+ + CaCO3: ↓ Levothyroxine (give 4 hrs apart)
- Rare: Riedel Thyroiditis Complications
- Iatrogenic: Thyroidectomy; Radio-iodine - Treatment: ↑ IHD; AF; Osteoporosis
- Drug: Lithium; Amiodarone; Carbimazole - Congenital: See below
- Associated: Down’s; Turner’s; Coeliac disease - SIADH: Chronic hypothyroidism can ↑ ADH
Hashimoto’s Thyroiditis
Description Investigations
- Incidence: 10x more common in women - Hist: Ashkenazi/Hurtle cells on biopsy
Presentation Management
- Specific: Firm, non-tender goitre - Levothyroxine: Replacement therapy
- Transient: May have acute phase of hyperthyroidism Complications
Causes - MALT: Hashimoto’s is associated with ↑ risk
- Auto-ABs: Anti-TPO; Anti-Thyroglobulin - AID: Coeliac; T1DM; Vitiligo
- Associations: Coeliac; T1DM; Vitiligo
Subacute (de Quervain’s) Thyroiditis
Presentation Investigations
- Phase 1: Hyperthyroidism; Painful goitre; ↑ ESR - Thyroid Scintigraphy: Globally ↓ uptake of I131
- Phase 2: Euthyroid Management
- Phase 3: Hypothyroidism - Supportive: Self-limiting and requires no mx
- Phase 4: Thyroid Fxn and Structure normalises - Pain: Aspirin or NSAIDs
Causes - Steroids: Used for severe cases
- Viral: Thought to be caused following a viral infx
