Endocrine and Metabolic

Question 1

What role does magnesium play in the synthesis and secretion of parathyroid hormone (PTH), and what are the consequences of low magnesium levels on PTH release?

Answer 1

Magnesium is crucial for the synthesis and secretion of PTH. Low magnesium levels can lead to impaired PTH release, resulting in hypoparathyroidism-like symptoms despite normal or elevated serum calcium levels.

Question 2

Sensory loss on the dorsal aspect of the 1st and 2nd metacarpals suggest damage to what nerve?

Answer 2

Radial nerve

Question 3

Which hormone upregulates alpha-1 receptors on arterioles?

Answer 3

Cortisol

Question 4

Which hormone directly stimulates aldosterone release?

Answer 4

Angiotensin II

Question 5

Which hormone stimulates pancreatic secretions rich in digestive enzymes?

Answer 5

Cholecystokinin (CCK).

Question 6

The zona glomerulosa releases aldosterone in response to raised __________________.

Answer 6

Angiotensin II, potassium, and ACTH levels.

Question 7

What hormone increases lipolysis?

Answer 7

Cortisol.

Question 8

Acanthosis nigricans may be seen in what conditions?

Answer 8

> Diabetes mellitus.
Hormonal disorders, such as PCOS and Cushing’s syndrome.
With use of certain medications, such as corticosteroids, niacin, and birth control pills.

Question 9

What is necrobiosis lipoidica?

Answer 9

Necrobiosis lipoidica is a rare, chronic granulomatous skin disorder often associated with diabetes mellitus, characterised by yellowish-brown patches with a red rim, typically on the shins.

Question 10

What are the common clinical features of necrobiosis lipoidica?

Answer 10

The condition begins as dull red papules or plaques that slowly enlarge into yellowish-brown patches with a red rim. The patches may be asymptomatic or tender, with central atrophy, shiny, pale, and thinned areas, and prominent blood vessels (telangiectasia).

Question 11

Which demographic is most commonly affected by necrobiosis lipoidica?

Answer 11

Necrobiosis lipoidica is three times more common in females than in males and usually develops in young and middle-aged adults.

Question 12

What percentage of patients with diabetes develop necrobiosis lipoidica?

Answer 12

Approximately 1% of patients with diabetes will develop necrobiosis lipoidica.

Question 13

What are the potential complications of necrobiosis lipoidica?

Answer 13

Complications include ulceration, which occurs in about one-third of cases, secondary bacterial infection, delayed healing, and rarely, squamous cell carcinoma developing in ulcerated areas.

Question 14

What is the primary method for diagnosing necrobiosis lipoidica?

Answer 14

Diagnosis is primarily clinical, based on the characteristic appearance of the lesions. A skin biopsy may be performed to confirm the diagnosis

Question 15

What are some differential diagnoses for necrobiosis lipoidica?

Answer 15

Differential diagnoses include elastolytic giant cell granuloma, necrobiotic xanthogranuloma, and sarcoidosis.

Question 16

What are the main treatment options for necrobiosis lipoidica?

Answer 16

Treatment options include topical and systemic corticosteroids, phototherapy (PUVA), photodynamic therapy, low-dose aspirin, and other immunomodulatory treatments.

Question 17

What is the pathophysiology of necrobiosis lipoidica?

Answer 17

The exact cause is unknown, but it involves collagen degeneration and a granulomatous response in the dermis, often affecting deeper fat layers and thickening dermal blood vessels.

Question 18

Can necrobiosis lipoidica occur in individuals without diabetes?

Answer 18

Yes, while it is predominantly associated with diabetes, necrobiosis lipoidica can also occur in individuals without diabetes or with other conditions such as rheumatoid arthritis.

Question 19

What is acanthosis nigricans?

Answer 19

Acanthosis nigricans is a skin condition characterised by dark, thick, velvety patches in body folds and creases, commonly affecting the armpits, groin, and neck.

Question 20

What are the common clinical features of acanthosis nigricans?

Answer 20

The main features include dark, thickened, velvety skin in body folds and creases. The affected skin may also be itchy, have an odour, and develop skin tags.

Question 21

What are the primary causes of acanthosis nigricans?

Answer 21

The primary causes include insulin resistance (often associated with type 2 diabetes), obesity, hormonal disorders (such as polycystic ovary syndrome), certain medications (like corticosteroids and birth control pills), and rarely, cancer.

Question 22

Which demographic is most commonly affected by acanthosis nigricans?

Answer 22

Acanthosis nigricans is more common in individuals with obesity and those with insulin resistance. It can affect people of any age but is often seen in younger individuals.

Question 23

What are the potential complications of acanthosis nigricans?

Answer 23

People with acanthosis nigricans are at a higher risk of developing type 2 diabetes. The condition itself can cause cosmetic concerns and discomfort due to itching or odour.

Question 24

Can acanthosis nigricans be a sign of cancer?

Answer 24

Yes, although rare, acanthosis nigricans can be associated with internal malignancies, particularly cancers of the stomach, colon, or liver.

Question 25

How is acanthosis nigricans diagnosed?

Answer 25

Diagnosis is primarily clinical, based on the characteristic appearance of the skin changes. Additional tests may include blood glucose tests to check for diabetes or insulin resistance, and sometimes a skin biopsy.

Question 26

What are some differential diagnoses for acanthosis nigricans?

Answer 26

Differential diagnoses include Addison’s disease, Cushing’s syndrome, and other conditions that cause hyperpigmentation or thickening of the skin.

Question 27

What are the main treatment options for acanthosis nigricans?

Answer 27

Treatment focuses on addressing the underlying cause, such as managing diabetes or obesity. Topical treatments may include retinoids, ammonium lactate, or hydroquinone. In some cases, laser therapy or chemical peels may be used to improve the skin’s appearance.

Question 28

What lifestyle changes can help manage acanthosis nigricans?

Answer 28

Lifestyle changes include weight loss, a healthy diet, regular exercise, and managing any underlying conditions like diabetes or hormonal imbalances.