Pathology

Question 1

Functions of the skin

Answer 1

Strong barrier to antigens and organisms
Thermoregulation
Fluid and electrolyte balance
Endocrine function
Protection from UV rays
Immune function
Sensory function

Question 2

Ground substances in the dermis

Answer 2

Hyaluronic acid and chondroitin sulphate

Question 3

Which type of the dermis contains appendage structures?

Answer 3

Reticular dermis

Question 4

Acanthosis

Answer 4

Increase in thickness in epithelium. Hyperplasia

Question 5

Hyperkeratosis

Answer 5

Increased thickness in the keratin layer

Question 6

Parakeratosis

Answer 6

Persistence of nuclei in the keratin layer

Question 7

Papillomatosis

Answer 7

Irregular epithelial thickening

Question 8

Spongiosis

Answer 8

Oedema fluid between squames appears to increase the prominence of intercellular prickles.

Question 9

4 main reaction patterns in skin

Answer 9

Spongiotic-intraepidermal oedema
Psoriasiform
Lichenoid
Vesiculobullous

Question 10

Psoriasiform

Answer 10

Elongation of the rete ridges

Question 11

Which condition is spongiotic-intraepidermal oedema seen in?

Answer 11

Eczema

Question 12

Which condition is psoriasiform seen in?

Answer 12

Psoriasis

Question 13

Which condition is lichenoid seen in?

Answer 13

Lichen planus and lupus

Question 14

Which conditions is vesiculobullous seen in?

Answer 14

Pemphigoid, pemphigus and dermatitis herpetiformis

Question 15

What are lichenoid disorders?

Answer 15

Damage to basal epidermis

Question 16

Histology in lichenoid disorders

Answer 16

Irregular saw tooth acanthosis
Hypergranulosis and orthohyperkeratosis
Band-like upper dermal infiltrate of lymphocytes
Basal damage with formation of cytoid bodies

Question 17

Prototypic condition in lichenoid disorders

Answer 17

Lichen planus

Question 18

Disorders falling under the heading lichenoid disorders

Answer 18

Lichen planus (main)
Discoid lupus
Some drug rashes
Erythema multiforme
Toxic epidermal necrolysis

Question 19

Main primary feature of immunobullous disorders

Answer 19

Blisters

Question 20

True or false: pemphigus is a common autoimmune bullous disease

Answer 20

False - it is a rare autoimmune bullous disease

Question 21

What happens to the epidermis in pemphigus?

Answer 21

There is loss of integrity of epidermal cell adhesion

Question 22

Which type of drugs does pemphigus respond to?

Answer 22

Steroids

Question 23

Most common subtype of pemphigus

Answer 23

Pemphigus vulgaris

Question 24

In pemphigus vulgaris, __ antibodies are made against __ _

Answer 24

IgG antibodies are made against desmoglein 3

Question 25

What does desmoglein 3 maintain?

Answer 25

Desmosomal attachments

Question 26

Steps in pemphigus vulgaris that leads to acantholysis

Answer 26

``` IgG antibodies against desmoglein 3 Immune complexes form on cell surface Complement activation and protease release Disruption at desmosomes End result is acantholysis ```

Question 27

Which parts of the body are most commonly affected by pemphigus vulgaris?

Answer 27

Skin - face, scalp, axillae, groin, trunk

Question 28

Which parts of the body may be affected by pemphigus vulgaris, but are not as common as skin?

Answer 28

Mucosa. Extensive mucosal involvement may be fatal

Question 29

Investigations for pemphigus vulgaris

Answer 29

Microscopy or fluorescence imaging

Question 30

What is bullous pemphigoid?

Answer 30

A condition where there is development of a subepidermal blister

Question 31

True or false: there is acantholysis in bullous pemphigoid

Answer 31

False - there is no evidence of acantholysis

Question 32

Pathophysiology of bullous pemphigoid

Answer 32

Circulating IgG antibodies react with antigen of the hemidesmosomes anchoring basal cells to basement membrane, resulting in local complement activation and tissue damage

Question 33

What does immunofluorescence show in bullous pemphigoid?

Answer 33

Linear IgG plus complement deposited around the basement membrane

Question 34

What do older lesions of pemphigoid show?

Answer 34

Re-epithelialisation of their floor, mimicking pemphigus vulgaris

Question 35

What does immunofluorescence in pemphigus vulgaris show?

Answer 35

Intraepidermal IgG

Question 36

What is dermatitis hepatoformis?

Answer 36

An autoimmune bullous disease

Question 37

Which condition does dermatitis hepatoformis have a strong association with?

Answer 37

Coeliac disease

Question 38

Clinical presentation of dermatitis hepatoformis

Answer 38

Intensely itchy lesions which are usually symmetrical, commonly found on the elbows, knees and buttocks

Question 39

Hallmark of dermatitis hepatoformis

Answer 39

Papillary dermal microabscesses

Question 40

Histology in dermatitis hepatoformis

Answer 40

Papillary dermal micro abscesses and deposits of IgA found in dermal papillae

Question 41

Pathogenesis of dermatitis hepatoformis

Answer 41

IgA antibodies target gliadin component of gluten but cross react with connective tissue matrix proteins Immune complexes form in dermal papillae and activate complement and generate neutrophil chemotaxis

Question 42

What does distribution of acne vulgaris reflect?

Answer 42

Sebaceous gland sites - face, upper neck, anterior chest

Question 43

Aetiology of acne vulgaris

Answer 43

Increased androgens at puberty Perhaps increased androgen sensitivity of sebaceous glands Keratin plugging of pilosebaceous units Infection with bacterium Corynebacterium acnes

Question 44

Bacteria that causes acne

Answer 44

Corynebacterium acnes

Question 45

Which gender is rosacea most common in?

Answer 45

Females

Question 46

Clinical presentation of rosacea

Answer 46

Recurrent facial flushing, visible blood vessels, pustules, thickening of the skin - rhinopehyma

Question 47

Triggers of rosacea

Answer 47

Sunlight, alcohol, spicy foods, stress

Question 48

Pathology in rosacea

Answer 48

``` Vascular ectasia Patchy inflammation Look for plasma cells and pustule formation Perifollicular granulomas Follicular demodex mites often noted Perhaps allergic reaction to mites ```