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Year 3 Special Senses > Dermatology > Flashcards

Flashcards in Dermatology Deck (63):
1

Eczema definition

Papules and vesicles on an erythematous base occuring on flexor surfaces.

2

Eczema epidemiology

-20% prevalence <12 yo
-Atopic most common

3

Eczema aetiology

-Primary genetic defect causing loss of function of filaggrin protein causing a defect in skin barrier function
-Family history of atopy usually present

4

Eczema presentation

-Itchy, erythematous, dry scaly patches on flexor surfaces (face and extensor surfaces in infants)
-Acute lesions: erythematous vesicular and exudative if infected
-Chronic scratching can lead to excoriation and lichenification
-Pitting and ridging of nails

5

Eczema management

-Avoid exacerbating agents
-Emolients

Topical steroids for flares:
-dipnovate
-dermovate
-immunomodulators for steroid sparing agents

Oral:
-antihistamines for symptomatic relief
-antibiotics (flucloxacillin) for secondary bacterial infection
-acyclovir for secondary herpetic infection

Severe non-responsive cases:
-Oral steroids --> phototherapy --> immunosuppressants (methotrexate, ciclosporin) --> biologics

6

Psoriasis definition

Chronic inflammatory skin disease caused by hyperproliferation of keratinocytes and inflammatory cell infiltration

7

Psoriasis aetiology

Variants:
-Chronic plaque - most common
-Guttate - raindrop lesions
-Seborrheic
-Flexural
-Pustular (palmar-plantar)
-Erythrodermic (total body redness)

Complex interaction between genetic, immunological and environmental factors

Precipitating factors: trauma, infection, drugs, stress, alcohol

8

Psoriasis presentation

-Well demarcated erythematous scaly plaques
-Lesions are itchy / burning / painful
-common on extensor surfaces and scalp
-Auspitz sign" scratch and removal of scales causes capillary bleeding
-50% have nail changes: pitting, onycholysis
-5% have psoriatic arthropathy: symmetrical polyarthritis, asymmetrical oligoarthritis, lone distal interphalangeal disease, psoriatic spondylosis, arthritis mutilans

9

Psoriasis management

General: avoid precipitating factors, emollients to reduce scales

Topical: localised and mild
-vitamin D analogues
-corticosteroids
-coal tar preparations
-dithranol
-retinoids
-keratolytics

Phototherapy: for extensive disease. UVB and photochemotherapy.

Oral: extensive and severe
-Methotrexate
-Retinoids
-Ciclosproin
-Biologicals: infliximab, etanercept, efazulimab

10

Acne defintion

Inflammatory disease of the pilosebaceous follicle

11

Acne aetiology

Hormonal: androgens
Contributing factors: increased sebum production, abnormal follicular keratinisation, bacterial colonisation (propionibacterium acnes), inflammation

12

Acne risk factors

-Pressure / friction on skin
-Oily lotions
-Teenage
-Stress

13

Acne presentation

Non-inflammatory lesions:
-Open comedones: blackheads
-Closed comedones: whiteheads

Inflammatory lesions:
-papules
-pustules
-nodules
-cysts

Commonly affects chest face and upper back

14

Acne management

Topical: benzoyl peroxide, antibiotics, retinoids

Oral: antibiotics, anti-androgens in females, retinoids

15

Rosacea definition

Chronic relapsing disease of facial skin characterised by recurrent episodes of facial flushing with persistent erythema, telangiectasia, papules and pustules.

16

Rosacea aetiology

-Chronic acneiform disorder of facial pilosebaceous glands with increased reactivity of capillaries to head causing flushing and eventually telangiectasia
-Full mechanism unknown but altered immune response involved
-Medication associations: amiodarone, topical steroids, nasal steroids, vit B6/12
-Flushing caused by heat / temp change, alcohol, caffeine, spicy food, stress, sun, vasodilators

17

Rosacea presentation

Symptoms:
-long history flushing
-progresses to constant flushing with obvious telangiectasia
-gritty eyes and facial oedema

Signs:
-skin not greasy, can be dry
-erythema and telangiectasia over forehead and chees
-nose / cheeks / forehead / chest / neck / ears affected
-prominent sebaceous glands
-nose may be enlarged / distorted - rhinphyma
-peri-orbital oedema

18

Rosacea managment

General:
-avoid precipitating factors: products containing sodium lauryl sulfate and topical steroids
-facial massage to reduce oedema
-daily suncream application

Pharmacological:
-topical: metronidazole, azelaic acid, oral abx if papulopustular
-isotretinoin used for resistant cases

19

Urticaria definition

Hives - itchy red rash resulting from swelling of superficial skin.

20

Urticaria aetiology

Activation of skin mast cells, resulting in histamine release This causes capillaries to leak leading to swelling. Angio-oedema can also occur when deeper tissues are involved.

Triggers can be:
-allergies: foods, bites, stings, medication - NSAIDs / ACEi
-viral infection
-skin contact
-physical stimuli: rubbing pressure, temperature

21

Urticaria presentation

-Typical lesion: central itchy white papule / plaque surrounded by erythematous flare. Vary in size and shape, can be accompanied by angioedema.
-Individual lesions transient - come and go within hours
-Classified as acute (<48h), chronic (> 6 weeks)

22

Urticaria managment

-Identify and treat cause
-Non-sedating H1 antihistamines: cetirizine, loratadine, fexofenadine
-If ineffective, increase dose x4 or add another antihistamine
-Short course oral steroids may be indicated if severe

23

Basal cell carcinoma definition

Slow growing locally invasive malignant tumour of epidermal keratinocytes

24

Basal cell carcinoma aetiology

-Tumour infiltrates local tissues though slow irregular growth
-Morbidity from local tissue invasion and destruction
-Chronic sun exposure

25

Basal cell carcinoma risk factors

UV exposure
Male
Xeroderma pigmentosa, albinism

26

Basal cell carcinoma presentation

-Typical lesion: translucent / pearly papule with raised areas, telangiectasia, rolled edges and a central depression
-Rodent ulcer: indurated and ulcerated centre. Slow growing but spreads deep and destroys tissue.

27

Basal cell carcinoma investigation

Biopsy

28

Basal cell carcinoma managment

-Surgical excision + histological examination of tumour and margins
-Micrographic surgery if high risk recurrent
-Radiotherapy if surgery not appropriate
-Cryotherapy, curettage and cautery

29

Squamous cell carcinoma defintion

Locally invasive malignant tumour of epidermal keratinocytes with potential to metastasise.

30

Squamous cell carcinoma aetiology

Dysplastic cells which span full thickness of epidermis and have spread into dermis.
Precursor's:
-Actinic keratosis: diffuse dysplastic cells within epidermis
-Bowen's disease: dysplasia spanning full thickness of epidermis

31

Squamous cell carcinoma risk factors

-UV light
-Susceptibility to light: fair skin (FItzpatrick type I), blonde, red hair
-Chemical carcinogens
-HPV
-Ionising radiation
-Immunodeficiency
-Chronic inflammation
-Genetic conditions: xeroderma pigmentosum, albinism

32

Squamous cell carcinoma presentation

-Indurated nodular keratinising / crusted tumour that may ulcerte or present as an ulcer without evidence of keratinisation
-Non-healng ulcer or growth in sun-exposed areas.
-Clinical appearance: enlarging module with centre becoming nectroting and sloughing, developing into ulcer
-Slow growing with reddish skin plaque - bleeding may occur
-May give rise to local mets / spread to local lymph nodes

33

Squamous cell carcinoma management

-Complete surgical excision, send for histopathological examination
-Other options: curettage and cautery, cryotherapy, topical, photodynamic therapy, radiotherapy

34

Malignant melanoma definition

Malignant growth of melanocytes.

35

Malignant melanoma aetiology

-Damage to melanocytes found in basal layer of epidermis, by UV
-Once melanoma spreads to dermis, can spread thorugh lymphatic system to local lymph nodes or via blood stream
-Common mets: lung, brain, bone, liver, lymph

36

Malignant melanoma risk factors

-Naevi: 100+ 5-20x higher risk
-Sun exposure
-Type I skin
-Actinic keratosis
-High SES

37

Malignant melanoma presentation

A: asymmetry
B: border irregular
C: colour irregular - brown and black
D: diameter > 7mm
E: evolving

38

Malignant melanoma differentials

For any brown patch:
-benign naevi
-seborrheic keratosis
-melanoma

39

Malignant melanoma investigation

-Visual inspection with dermatoscope and removal for histology
-Diagnosis based on full-thickness biopsy
-Breslow thickness measure to determine malignant potential

40

Malignant melanoma management

-Surgical excision definitive treatment
-Radiotherapy useful
-Chemo if metastatic

41

Impetigo definition

Acute superficial bacterial infection most common in children

42

Impetigo aetiology

-Most commonly S. aureus, can be Strep pyogenes.
-Non-bullous, bullous or ulcerated

43

Impetigo risk factors

-Immunosuppressed
-Summer
-Atopic eczema
-Scabies
-Skin trauma

44

Impetigo presentation

-Primarily affects exposed areas: face, hands
-Irregular crops or irritable superficial plaques with honey crusting
-Extend when healing to form annular or arcuate lesions
-Lymphadenopathy, fever, malaise

45

Impetigo management

-Wound hygiene
-Antibiotics to carrier sites to prevent recurrence
-Avoid contact with others

46

Cellulitis definition

Common bacterial infection of lower dermis / subcutaneous tissue

47

Cellulitis aetiology

S. pyogenes
S. aureus
P. aeruginosa

48

Cellulitis presentation

-Can affect any site but usually unilateral limb
-Localised area of painful, red, swollen skin
-Peau d'orange
-Blistering, erosions, ulceration, purpura
-Poorly demarcated borders
-Red lines streaking away represent progression of infection into lymphatic system
-Crepitus if anaerobic organism
-Systemic signs of infection

49

Cellulitis management

Uncomplicated: oral abx 5-10 days, symptomatic relief for pain and fluid loss

Complicated: systemic illness. Fluids, IV abx with oral switch when fever settles, cellulitis regresses and CRP reducces. O2.

Recurrent: avoid trauma, wear long sleeves, skin hygiene. Avoid blood tests in affected site. Keep swollen limbs elevated to aid lymphatic circulation.

50

Molluscum Contagiosum definition

Common skin infection caused by pox virus, transmitted by direct contact.
Most common in children < 10

51

Molluscum Contagiosum aetiology

Molluscum contagiosum mvirus. Spread by:
- direct contact
-indirect through contaminated objects
-auto-inoculation into site by scratching
-sexual

Incubation 2weeks - 6months

52

Molluscum Contagiosum presentation

-Clusters of small round papules 1-6mm, white / pink / brown. Umbilicated (central depression). Contains cheesy white material.
-Located in warm moist areas: axilla, knees, groin
-Papules in a row if from scratching
-Induce surrounding dermatitis

53

Molluscum Contagiosum management

-Usually self-limiting
-Physical: burst papules, cryotherapy, curettage and cautery, laser ablation
-Medical: antiseptics e.g. h2o2 cream, salicylic acid, topical abx

54

Seborrhoeic Keratosis definition

Common benign hyperkeratotic skin lesions associated with ageing.

55

Seborrhoeic Keratosis aetiology

Degenerative condition with UV role in causation. Oncogenic mutations. Full aetiology poorly understood.

56

Seborrhoeic Keratosis presentation

-Flat-topped lesions, 1mm-several cm with well circumscribed border
-Usually deeply pigmented - brown / black
-Surface pitted and irregular with visible keratin dots
-Multiple lesions may align along skin folds
-Usually asymptomatic - may become irritated, itchy or inflamed

57

Seborrhoeic Keratosis management

Surgical removal
Curettage and cautery
Laser
Shave biopsy
Chemical peel

58

Necrotising fasciitis

Life threatening infection involving any layer of deep soft tissue compartment - dermis, subcut, fascia, muscle

59

Necrotising fasciitis aetiology

-Wide spread necrosis
-Organism spread from subcut tissue along superficial and deep fascial planes
-Muscle usually spared
-Multi-bacterial symbiosis and synergy
-Common organisms: S. pyogenes, anaerobes + GN

60

Necrotising fasciitis presentation

-Patients systemically ill with disproportionately severe pain - only minor skin changes in initial stages
-Can affect anywhere but usually extremities, perineum or trunk
-Starts with localised pain swelling and oedema with infection poorly demarcated
-Systemic illness
-Develops into tense oedema, may be bullae, discoloured skin, crepitus due to subcut gas, pain may progress to anesthesia as nerves are destroyed, broad erythematous tract in skin
-Hypotension and shock
-Confusion, apathy

61

Necrotising fasciitis investigation

-Exploratory surgery: macroscopic features of grey necrotic tissue
-Bloods: increased WCC / CRP / CK / urea, decreased sodium
-Microbiology: cultures, wound swab, gram stain, fungal culture

62

Necrotising fasciitis mangement

-Early and aggressive wound debridement
-Broad spec high dose abx
-Close monitoring and supportive measures
-Nutritional support due to high protein and fluid loss

63

How does Lichen Planus normally present

6 P's
Planar (flat-topped)
Purple
Polygonal
Pruritic
Papules
Plaques