Other: Nutrition and the Skin

Question 1

How does obesity affect sebaceous glands?

Answer 1

Increased androgens produced in peripheral fat stimulate sebaceous glands, which can lead to acne

Question 2

What is hirsutism?

Answer 2

Increased hair in females in male distribution e.g. beard area, linked to hyper-androgenism

Question 3

How does obesity affect the endocrine roles of subcutaneous adipose tissue?

Answer 3

Obesity can result in increased hormone production, e.g. testosterone, by adipose tissue - hyper-androgenism

Question 4

How does obesity affect the lymphatics?

Answer 4

Pressure from fat impedes lymphatic flow and causes leakage of protein rich lymphatic fluid into subcutaneous tissues

Question 5

How does obesity affect the barrier function of skin?

Answer 5

Results in increased trans-epidermal moisture loss meaning skin tends to be dry

Question 6

What is androgentic alopecia?

Answer 6

Male pattern balding in men and women, linked to hyper-androgenism

Question 7

What is intertrigo?

Answer 7

Macerated red plaques which develop in skin folds due to high moisture levels, friction, increased pH and reduce barrier function

The plaques are prone to secondary infection

Question 8

How does obesity affect circulation?

Answer 8

Obesity is associated with microvascular dysfunction resulting in increased skin blood flow which may contribute to hypertension

Question 9

What causes kwashiorkor?

Answer 9

Very low protein intake with reasonable carbohydrate intake

There is oedema, children often develop a ‘pot belly’

Question 10

Define marasmus

Answer 10

Global nutrient deficiency causing weight loss by fat breakdown

Patients will be very thin with muscle wasting and dry, wrinkled loose skin

Question 11

How does obesity contribute to chronic venous insufficiency?

Answer 11

Abdominal obesity resists venous return from the legs, the veins dilate and their valves become incompetent causing increased hydrostatic pressure

This leads to venous dermatitis, chronic scaring and possibly eventually venous ulceration

Question 12

What is hidradenitis suppurative?

Answer 12

Chronic inflammatory disease where boils and abscesses form and scar in apocrine gland areas (especially axilla and groin), linked to hyper-androgenism

Question 13

What are skin tags?

Answer 13

Small, soft skin-coloured growths frequently found around axillae and neck areas, associated with insulin resistance

Question 14

How does obesity predispose individuals to skin infections?

Answer 14

Patients will have increased tendency to bacteria, fungal, and yeast infections, especially in skin folds and areas where circulation is affected

Question 15

What are stretch marks?

Answer 15

Type of scarring associated with dermal connective tissue injury in response to local stretching forces e.g. rapid weight gain in pregnancy and obesity, linked to hyper-androgenism

Question 16

How does obesity contribute to lymphodema?

Answer 16

Increased subcutaneous fat causes reduced lymphatic drainage, leading to swelling, chronic inflammation and fibrosis

As tissue oxygenation is reduced, bacterial overgrowth can occur and cellulitis develops easily → further lymphatic damage

Question 17

Define acanthosis nigricans

Answer 17

Velvety thickening and pigmentation of skin folds, usually axillae, associated with insulin resistance

Question 18

Define food allergy

Answer 18

An immune reaction, usually IgE mediated, to food

Question 19

Define food intolerance

Answer 19

A non-immune reaction to food e.g. lactose intolerance where lactase enzyme deficiency leads to poor breakdown of lactose → unabsorbed lactose causes symptoms

Question 20

How can obesity affect collagen and wound healing?

Answer 20

Animal studies suggest the reduced mechanical strength of skin in obesity is due to a failure of collagen deposition to match the increased surface area

Question 21

Which form of psoriasis is particularly aggravated by obesity?

Answer 21

Flexural psoriasis

Question 22

How does obesity affect the apocrine and eccrine skin glands?

Answer 22

Increased activity in skin folds increases moisture/skin maceration

Friction in folds increases irritation