Dermatology CBL

Question 1

What epithelium is the epidermis?

Answer 1

Stratified squamous keratinising epithelium

Question 2

5 epidermal layers

Answer 2

Basale
Spinosum
Granulosum
Lucidum
Corneum

Question 3

Langerhan Cells

Answer 3

Dendritic cells, residing in epidermis. Ingest, rpocess and present antigens to T lympocytes

Question 4

Melanocytes

Answer 4

Originate in neural crest and migrate to skin during early development. Live in dermis or epidermis and make pigment (melanin). Also important for skin and hair pigmentation.

Question 5

Diff dx of chronic, red scaly skin?

Answer 5

Psoraisis 
Exzema
Seborrhoeic dermaitits
Tinea (fungal) 
Pityriasis rosea

Question 6

Clinical features of psoriasis

Answer 6

Well demarcated plaques on extensor surfaces
Silvery scale, hyperkeratosis
Salmon-pink inflammatory base
Flexural involvement around ears
Painful hacks and fissures within plaques on feet

Question 7

Risk factors for psoriasis

Answer 7

Genetic - HLA subtypes.
Environmental - drugs e.g. lithium
Infection
Stress

Question 8

Pathogenesis of psoriasis

Answer 8

Hyperproliferatioon of epidermal keratinocytes leading to reduction in transit time from basal layer to stratum corneum.

Activation of t-lymphocytes.

Thickening of epidermis, epidermal neutrophils and dilated dermal capillaries

Production of cytokines e.g. TNFa and Interleukins

Question 9

Rheumatological signs linked with psoriasis

Answer 9

Pain and tenderness on active and passive movement of fingers and toes
Synovitis/red/swelling
Limited range of movements
Stiff sore back

Question 10

Psoriatic arthropathy

Answer 10

Seronegative arthritis typically affecting the sacro-illiac and distal interphalangeal joints

Question 11

Psoriasis is more common in px with which disease?

Answer 11

Chrons disease

Question 12

Tests for psoriatic arthritis

Answer 12

FBC, Inflamm markers (CRP), RF (Negative), Alkaline phosphatase

Question 13

Treatment for psoriasis

Answer 13

Topical - tar, corticosteroids, retinoids, Vit D3 analogs, dovobet

Systemic - retinoids, immunosuppression (methotrexate)
Final option - biological (infliximab, adalumimab)

Question 14

Itchy skin, improves on holiday?

Answer 14

Atopic eczema most likely, possible element of allergic contact dermatitis

Question 15

Factors involved in development of atopic eczema?

Answer 15

Defective barrier function i.e. genetic fillagrin skin protein dysfunction, irritant soaps, overworking, poor handcare

Question 16

Investigations for atopic eczema

Answer 16

Skin swab (2ndary bacterial infection) 
Consider fungal skin scrape to exclude tinea

Contact dermatitis patch testing

IgE count

Question 17

Tx of atopic eczema

Answer 17

Emollient moisturisers (creams and oinments)
Potent topical steroid
Finger tip unit applications

If doesnt improve -
UV phototherapy
Oral alitretinoin
Systempic immunosuppresives (methotrexate)

Question 18

Alopecia areata clinical symptoms/features

Answer 18

Well circumscribed areas of hair loss
Non scarring
Follicular architecture intact
Hair pull test positive
Vellous white hair growth
Occassional nail changes

Question 19

Aetiologies involved in development of alopecia areata

Answer 19

Exact mechanism unknown - possible autoimmune?

Question 20

Therapies for alopecia areata

Answer 20

Topical steroid
Injected steroid
Irritant contact dermatitis treatments e.g. DCP
UVB phototherapy
Minoxidil for widespread hair loss

Question 21

Different patterns of non-scarring alopecia areata?

Answer 21

Single patch, localised
Multiple patches
Widespread
Alopecia totalis
Alopecia universalis
Parietal pattern

Question 22

What conditions may cause hair loss including those that scar?

Answer 22

Androgenic male pattern hair loss
Scalp cellulitis
Syphilis
Untreated ringworm

Question 23

Brown marks on skin differential dx

Answer 23

Melanocytuic naevi (moles)
Seborrhoeic keratoses (warts)
Freckles
Melanoma
Hyperpigmentation
Pigmented basal cell carcinoma

Question 24

Melanoma important dx features

Answer 24

Irregularity in shape or colour
Change in size
Bleeding or ulceration, inflammation, irritation
Lesions >5mm

Question 25

Findings on biopsy of melanoma

Answer 25

>5mm Active melanocytic lesion with junctional and invasive intradermal component Cells are large, contain mitotic features Pale cells are neoplastic melanocytes spreading in the epidermis --> dermis Stain for melan A Breslow thickness

Question 26

Risk factors for melanoma

Answer 26

UV irradiation (natural and artificial) Countries with populations of white skinned individuals exposed to strong sunshine Genetic Numerous atypical naevi

Question 27

Genetic mutation in melanoma

Answer 27

Tumour suppressor gene CDKN 2A

Question 28

Preventative measures for melanoma's

Answer 28

Avoid UV exposure - sunblock Avoid sunburn Stop using sunbeds Follow up px with atypical naevi or strong fhx of melanoma

Question 29

Most important prognostic feature for melanoma?

Answer 29

Tumour thickness - breslow thickness

Question 30

Staging for melanomas

Answer 30

Stage 1 - Tumours <1mm thick Tumours 1-2mm thick without ulceration Stage 2 - Tumours 1-2mm thick with ulceration Stage 3 - regional lymph node involvement Stage 4 - Distant metastases

Question 31

Tx of melanoma

Answer 31

Excision with narrow margins then wide local excision Sentinel node studies offered to px with thicker melanomas

Question 32

Distinguishing arterial with venous ulcer?

Answer 32

Venous tends to be less painful, more superficial and diffuse

Question 33

Social/lifestyle factors involved in the development of venous ulcer?

Answer 33

Multiple pregnanices Varicose veins Standing in a shop

Question 34

Important initial inv in venous leg ulcer

Answer 34

Ankle brachial pressure index should be roughly equal | 0.8 ratio may suggest occulsion

Question 35

Initial tx for venous leg ulcer

Answer 35

Compression - 3 layer bandaging Compression stockings Moisturiser emollient Topical steroid

Question 36

If the ulcer didn't heal - what other investigations should be done?

Answer 36

``` MRI angiography SKin biopsy incase of ISD Bacterial swabs Exclude drug ulceration Patch testing for bandages, dressings and steroids ```

Question 37

Causes of leg ulceration

Answer 37

``` Arterial Diabetic Neuropathic Pressure sores Trauma Infection ```

Question 38

Teenage px presents with spots on face. What is the differencial dx?

Answer 38

Acne vulgaris Rosacea Folliculitis Pustular drug reaction

Question 39

Features needed for a diagnosis of acne vulgaris

Answer 39

Papules Pustules Comedones May also be evidence of scarring, hyperpigmentation, nodules Chest, back and upper arms may also be involved

Question 40

Aetiology of acne vulgaris

Answer 40

Seborrhoea, sebum retention and inflammation May be related to excess sensitivity of sebaceous end organs to androgens Ovarian or adrenal hyperandrogenism Sebum retention is hyperkeratinisation of the sebaceous duct

Question 41

Therapies for acne vulgaris

Answer 41

``` Topical antiseptics - benzyl peroxide Topical Antibiotics - clindamycin Oral antibiotics - limecycline, doxycyline Duac - clindamycin/benzyl peroxide OC - Dianette Oral retinoids - isotretinoin ```

Question 42

Implications of using oral isotretinoin in a teenage girl

Answer 42

``` Common side effects - Swelling of lips Fragile and weaker skin Nosebleeds Photosensitivity Elevated liver enzymes Alopecia Vision problems ``` ``` Serious side effects - Major birth defects Depression Erectile dysfunction Hepatotoxicity ```

Question 43

Irregular menstruation, excess hair and severe acne?

Answer 43

Consider PCOS and congenital adrenal hyperplasia Do hormone profiling - testosterone, progesterone, prolactin

Question 44

Social and psychological implications of acne

Answer 44

Depression Social withdrawal Self esteem and body image issues

Question 45

Dysmorphophobic acne

Answer 45

Some px consider their minor acne to be severe.

Question 46

A genetic compound deficiency within the skin has been implicated in eczema, what is it?

Answer 46

Filaggrin deficiency