big derm document

Question 1

acanthosis

Answer 1

thickening of the epithelium

Question 2

acantholysis

Answer 2

seperation of individual keratinocytes

Question 3

hyperkeratosis

Answer 3

increased thickness in keratin layer

Question 4

parakeratosis

Answer 4

persistence of nuclei in keratin layer

Question 5

papillomatosis

Answer 5

irregular thickening of the epithelium

Question 6

spongiosis

Answer 6

intercellular oedema in the epidermis

Question 7

what are features of topical steroids

Answer 7

anti-inflammatory
anti-proliferative
vasoconstrictive

Question 8

examples of topical steroids and their potencies

Answer 8

Mild: hydrocortisone 1%

Moderate: Eumovate (clobetasone butyrate 0.05%)

Potent: Betnovate (betamethasone valerate 0.1%).

Very potent: Dermovate (clobetasol proprionate 0.05%).

Question 9

side effects of topical steroids

Answer 9

skin thinning 
immunosuppression 
stretch marks 
purpura 
steroid rosacea 
systemic absorption - adrenal suppression, cushings syndrome 
flare up of conditions:psoriasis

Question 10

when would you use topical steroids

Answer 10

eczema (dermatitis)
psoriasis
lichen planus
keloid scars

Question 11

what is the function of emoillients

Answer 11

rehydrate the skin - used in all dry/scaly conditions especially eczema - 300-500g weekly

Question 12

examples of emollients

Answer 12

cream = Diprobase, E45
ointments = epiderm
wet wraps - very dry skin

Question 13

what is the function of calicneurin inhibitors and give examples

Answer 13

suppress lymphocyte activation - ‘Calcineurin inhibitor’ means that they work with the immune system by blocking one of the chemicals that can contribute to the flaring of atopic eczema

topical treatment of atopic eczema

examples = tacrolimus, pimecromilus

can cause burning sensation on application

Question 14

what is the antiviral for shingles/eczema herpeticum

Answer 14

acyclorvir

Question 15

when are keratolytics used

Answer 15

soften keratin

used for viral warts and hyperkeratotic eczema and psoriasis

Question 16

embryologically what is the dermis derived from

Answer 16

ectoderm

Question 17

embryologically what is the epidermis derived from

Answer 17

mesoderm

Question 18

embryologically what are melanocytes derived from

Answer 18

neural crest

Question 19

main function of keratinocytes

Answer 19

• production of keratin
• synthesis of vitamin D
• variety of immune functions

Question 20

what are the layers of the epidermis

Answer 20

1. keratin layer
2. granular layer
3. prickle cell layer
4. basal cell layer

Question 21

describe the basal layer

Answer 21

• deepest layer

- contains stem cells, merkel cells, melanocytes, keratin, and a single layer of small cuboidal keratinocytes

Question 22

describe the prickle cell layer

Answer 22

• sits above the basal layer

- polyhedral keratinocytes

Question 23

describe the granular layer

Answer 23

• 2-3 layers of flattened keratinocytes and langerhans cells
• function = to produce the cornified envelope by producing keratin and additional proteins such as Filaggrin and Involucrin
• lack of nuclei
• high lipid content
• odland bodies

Question 24

describe the keratin layer

Answer 24

AKA stratum corneum

function = waterproof barrier

composed of = corneocytes, keratin, lipids, filaggrin

Question 25

where do melanocytes migrate from and what is their function

Answer 25

migrate from neural crest function = producing melanin from tyrosine

Question 26

what are langerhan cells and where are they found

Answer 26

found: prickle cell layer function: dendritic cells that present antigens to the T cells distinguishing: Birckbeck granules (rod shaped)

Question 27

where are merkel cells found and what is their function

Answer 27

found: basal layer function: mechanoreception

Question 28

what is the dermo-epidermal junction

Answer 28

avascular zone that acts as the interface between the dermis and the epidermis

Question 29

what do diseases that alter the dermo-epidermal junction result in

Answer 29

bullae

Question 30

what are functions of the dermo-epidermal junction

Answer 30

- semi permeable membrane that acts as a barrier to filtration - support, anchorage and adhesion of epidermal cells

Question 31

what are the layers of the dermo-epidermal junction

Answer 31

1. hemi desmosomes 2. lamina lucida 3. lamina densa 4. sub lamina densa

Question 32

what is the function of the dermis

Answer 32

cushion and support the epidermis

Question 33

what does the dermis consist of

Answer 33

mainly connective tissue: - collagen - elastin - ground substances, which is the gel like substance composed of glycoaminoglycans

Question 34

what are cells found in the dermis

Answer 34

``` Mast cells Fibroblasts Macrophages Lymphocytes Langerhans cells ```

Question 35

function of sebaceous glands

Answer 35

produce sebum in a hormone sensitive manner, with the sebum acting to prevent moisture loss and protect against infection face, chest, back

Question 36

function of apocrine glands

Answer 36

produced scented, oily fluid found deep in dermis, project up towards and open out into the hair follicle (axilla and perineum)

Question 37

function of eccrine glands

Answer 37

sweat glands and open directly onto the skin found everywhere especially palms, soles and axillae function = thermoregulation and are under control of autonomic nervous system

Question 38

what are the nerves of the skin

Answer 38

Meissners corpuslces: sensory nerves found high in the dermis and respond to light touch and vibration Pancinian corpuscles: sensory nerves found deeper in the dermis and respond to heavy, deep pressure

Question 39

what are the 3 types of hair

Answer 39

Terminal: course hair found on the scalp, beard and pubic region. Vellus: fine hair found on the face of women and in pre pubertal children. Lanago: soft hair found in new borns.

Question 40

what are the phases of the hair cycle

Answer 40

Anagen: period of active growth. Catagen: period of no active growth but with involution of the hair. Telogen: resting phase of the cycle when the hair falls out.

Question 41

what is a type 1 antibody mediated reaction

Answer 41

anaphylaxis and or urticaria

Question 42

what is type 2 cytotoxic reactions

Answer 42

blistering reaction - pemphigus and pemphigoid

Question 43

what's a type 3 immune complex mediated reaction

Answer 43

purpura/vasculitis/rash

Question 44

what is a type 4 cell mediated delayed hypersensitivity reaction

Answer 44

T cell mediated. erythema and rash

Question 45

what is an exanthematous drug eruption

Answer 45

- most common - type 4 reaction - widespread symmetrical rash - mucous membrane usually spared - itch and fever common

Question 46

what drugs cause exanthematous drug eruptions

Answer 46

- penicillins - sulphonamides - erythromycin - strepyomycin - allopurinol - anti epileptics (carbamazepine, phenytoin) - NSAIDs

Question 47

what are urticarial drug reactions

Answer 47

usually immediate IgE mediated hypersensitivity reaction (type 1) after rechallenge with drug direct release of inflammatory mediators from mast cells on first exposure

Question 48

what drugs cause urticarial drug reactions

Answer 48

- aspirin - opiates - NSAIDs - muscle relaxants - vancomycin - quinolones

Question 49

what drugs cause drug induced bullies pemphigoid

Answer 49

ACE inhibitors Penicillin Furosemide

Question 50

what are fixed drug eruptions

Answer 50

= well demarcated round/ovoid plaques - red and painful - hands genetalia lips - resolves with persistent pigmentation when drug stopped - can re occur at same site on re-exposure

Question 51

what are drugs associated with fixed drug reactions

Answer 51

- tetracycline, doxycycline - paracetamol - NSAIDs - Carbamazepine