Inflammatory Dermatoses

Question 1

what are the layers of the skin SKIN LAYERS

Answer 1

Epidermis
Dermis
subcutaneous tissue

Question 2

what layers is the BM between

Answer 2

Epidermis and dermis

Question 3

what important structures are in the dermis

Answer 3

pilosebaceous unit - hair follicles, sebaceous glands + arrector pili muscles

Question 4

what are the 2 types of sweat glands

Answer 4

apocrine glands - axilla, groin (more smelly)

sebaceous glands -

Question 5

what immunity role does sebum have

Answer 5

chemical that suppress growth of bacteria fungi

Question 6

what is the skin mostly made of and what is the life cycle of these cells

Answer 6

keratinocytes (make keratin) which differentiate upwards end up as stratum corneum = barrier function

here they are dead cells and lack nuclei
(basal cell - prickle cell - granular cell - keratin)

Question 7

what connections are within the startup spinosum

Answer 7

desmosomes

Question 8

what are the layers of the epidermis

Answer 8

Cornuem
Lucidum
Granulosum
Spinosum
Basale

Question 9

what holds cells in the stratum corneum together

Answer 9

between corneocytes there is a glue made of lipids/proteins - maintains intergrity

filagrin is one of the proteins in glue

Question 10

what mutation predisposes to eczema

Answer 10

Mutation in filagrin = skin genetically predisposed to be dry therefore leads to exam

Question 11

define Atopy

Answer 11

tendency to develop hypersensitivity

Question 12

give 3 examples of atopic diseases

Answer 12

eczema, asthma, hayfever

Question 13

ATOPIC eczema what is the underlying problem

Answer 13

defective barrier function in skin

Question 14

what is the ATOPIC MARCH

Answer 14

tend to develop conditions in this order:


Eczema (1-2)
Food allergy (1-2)
later asthma
finally rhinitis/hayferver

i.e. Eczema leads to development of other atopic diseases

Question 15

why does the atopic march happen

Answer 15

Due to the eczema

They are becoming sensitised to environmental allergens which manifests as other atopic diseases

Question 16

describe the development of acute eczema

Answer 16

intrinsic defect
extrinsic factors penetrate

these activate CD4+ lymphocytes and Th2 response
IgE production and mast cell degranulation

Question 17

what external factors penetrate the stratum corneum activating the immune response

Answer 17

Allergens - house dust mite
Irritants - detergents in soap
Pathogens - staphylococcus

Question 18

when acute eczema become chronic what happens immunologically

Answer 18

Activation of CD8+lymphocytes and the Th1 response now dominates

Question 19

what is a sign of filagrin gene mutations

Answer 19

Palmar hyperlinearity

lines more visible, prominent

Question 20

describe appearance of acute eczema

Answer 20

red, raw, weepy, sore, small vesicles/blisters,

poorly defined edges

Question 21

what is eczema in babies called where does it appear

Answer 21

Infantile atopic eczema

appears in areas which baby can rub/get to - face, legs, knees

Question 22

as patients grow older what other sites will eczema appear in

Answer 22

present in more flexural areas - elbows knees, popliteal fossae, neck, cubital fosse

Question 23

what changes occur in the appearance of eczema when it becomes chronic

Answer 23

less red, more skin coloured,

lichenification - skin markings are more visible due to chronic rubbing (looks thicker)

Question 24

what is severe eczema called

Answer 24

Erythrodermic eczema means patient is red all over and systemically unwell

hospital admission required + staph aureus can perpetuate eczema and cause infections

Question 25

what viral condition can eczema predispose to and what is this called

Answer 25

HSV eczema herpeticum

Question 26

how does eczema herpeticum present what problems can it cause

Answer 26

presents at small blisters which break down to form blisters - painful can become septic - herpes encephalitis

Question 27

what is Seborrhaeic eczema

Answer 27

overgrowth of yeast plus eczema (dandruff in hair) not as itchy, cosmetics issue

Question 28

appearance of location of Seborrhaeic eczema

Answer 28

greasy scale with redness around nasal folds, eyebrows and scalp

Question 29

what is Allergic contact dermatitis

Answer 29

allergy to specific product - eye drops, makeup, perfume , nickel (jewelry), rubber Atopic eczema predisposes PPD dye - hair dyes and some henna tattoos

Question 30

what is discoid dermatitis, what people does it occur in

Answer 30

disc shapes scattered around the body - elderly, people who over wash - need to use less soap

Question 31

what does psoriasis present with

Answer 31

SYMMETRICAL skin lesions - plaques salmon pink, with silvery scale, well defined

Question 32

immunologically and pathologically what is happening in psoriasis

Answer 32

T cells proximate within dermis, stimulate cytokine release TNF alpha, neutrophils in epidermis, overproduction of keratinocytes = thickening of epidermis

Question 33

list the main histological signs of psoriasis

Answer 33

Acanthosis - Thickening of epidermis hyperkeratosis - thickening and scaling of top layer inflammation dilated blood vessels parakeratosis

Question 34

Distribution of skin lesions in psoriasis

Answer 34

scale outside of elbows, knees, umbilicus, nasal cleft but can occur anywhere Occurs in places of trauma, pressure - like soles of foot