Dermatology Flashcards

1
Q

Definition of acne? Causes?

A

Inflammatory disease of the pliosebaceous follicle.

Causes

  • Hormonal (androgens)
  • Increased sebum production
  • Abnormal follicular keratinisation
  • Bacterial colonisation
  • Inflammation
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2
Q

Signs/symptoms of mild and moderate/severe acne?

A

Mild

  • Non-inflammatory lesions
  • Open and close comedones (blackheads and whiteheads)

Moderate/Severe

  • Inflammatory lesions
  • Papules, pustules, nodules and cysts
  • Affects face +/- torso
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3
Q

Management of Acne?

A

Topical Therapies

  • Benozyl peroxide (2.5%)
  • Topical retinoid (isotretinoin) - avoid in prego
  • Topical abx (dalacin T)

Oral Therapies

  • Tetracycline, oxytet, doxy, lymecycline
  • Erythro if pregnant or <12
  • COCP if contraception needed

Oral Retinoids

  • Roaccutane
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4
Q

Mode of action of isotretinoin? Side effects?

A

Reduced sebum production and reduced pituitary hormones

  • Teratogenic (contraception during and 1 month after)
  • Skin and mucosal dryness
  • Depression
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5
Q

Definition of eczema?

A

Inflammation characterised by papules and vesicles on an erythematous base

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6
Q

Presentation of eczema?

A

Symptoms

  • Itchy, erythematous and dry scaly patches
  • Infants = face/extensor limbs
  • Adults = flexor limbs
  • Acute lesions = erythematous, vascular and exudative

Signs

  • Chronic scratching –> excoriations and lichenificaion
  • May show nail pitting and ridging of nails
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7
Q

Complication of eczema (secondary infection)?

A

Bacterial

  • Staph aureus/Strep pyogenes
  • Golden crust and postulation
    • Rx = antiseptic washes and topical antibacterial ointments. Oral abx and topical steroids for widespread infections.

Viral

  • Chickenpox, molluscum contagiosum
  • Eczema herpeticum = monomorphic clusters of vesicles that erode and crust. Systemic aciclovir and same day derm referral.
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8
Q

General advice in eczema?

A
  • Avoid irritants (soap and biological detergents)
  • Clothing to skin should be pure cotton where possible
  • Cut nails short to reduce damage from scratching
  • Mittens at night in the very young
  • Avoid proven precipitants (e.g. cows milk)
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9
Q

Medical management of eczema?

A

Emolients

  • Apply liberally 2+ times a day and after bath.

Topical Steroids

  • Benefits outweight risks - lowest effective strength.
  • Apply thinly and don’t use on the face.

Others

  • Antihistamines for itching
  • Abx/antivirals for secondary infection
  • 2nd line = topical calcineurin inhibitors (tacrolimus), bandages and stockinette garmets
  • 3rd line = phototherapy and systemic agents
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10
Q

Potency of topical steroids?

A

Mild = 1% hydrocortisone

Moderate = 2.5% hydrocortisone

Strong = betnovate/dermovate

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11
Q

Definition of psoriasis? Precipitating factors?

A

Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration.

  • Trauma (koebner phenomenon)
  • Infection (tonsilitis)
  • Drugs/alcohol
  • Stress
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12
Q

Types of psoriasis?

A
  • Chronic plaque (most common)
  • Guttate (raindrop lesions)
  • Seborrhoeic (naso-labial and retro-auricular)
  • Flexural (body folds)
  • Pustular (palmar-plantar)
  • Erythrodermic (total body lesions)
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13
Q

Symptoms and signs of psoriasis?

A

Symptoms

  • Well-demarcated erythematous scaly plaques – usually extensor surfaces of body and over scalp
  • Can be itchy, burning or painful

Signs

  • Auspitz sign (scratch and gentle removal of scales causes capillary bleeding)
  • 50% have nail changes (pitting, onycholysis)
  • 5-8% have associated psoriatic arthropathy (seronegative)
  • Oligo/monoarthritis, psoriatic spondylitis, asymmetrical polyarthritis, arthritis mutilans (destructive – DIPJs), rheumatoid-like polyarthritis
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14
Q

General advice/management of psoriasis?

A
  • Education
  • Avoid precipitating factors
  • Emollients to reduce scales and relieve irritation
  • For topical treatments choose a base the patient prefers (ointment, cream, lotion, gel or foam)
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15
Q

Management of psoriasis?

A

Topical Therapies (localised and mild)

  • Vitamin D analogues (dovonex)
  • Topical steroids (betnovate) - no more than 8 weeks
    • Combination = dovobet
  • Coal tar preparations (Exorex) - if widespread

Phototherapy

  • If >10% body surface or uncontrolled by conventional therapy
  • Narrowband UVB phototherapy/PUVA (PUVA increases SCC risk)

Oral Therapies

  • Non-biologics - methotrexate, ciclosporin, acitretin
  • Biologics - TNF-a antagonists, IL antagonists
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16
Q

Side effects of non-biologic therapies for psoriasis?

A
  1. Methotrexate
    • Once a week. Avoid in young due to risk of hepatic fibrosis long term.
    • Monitor FBC/LFT
  2. Ciclosporin
    • ↑BP and renal dysfunction
  3. Acitretin (oral retinoid)
    • Teratogenic, dry skin, ↑lipids, glucose and LFTs
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17
Q

What are warts? What causes them?

A

Papules or nodules with a hyperkeratotic or filiform surface, most commonly seen at sites of trauma (fingers, elbows, knees and pressure points on soles) in children

Caused by HPV in keratinocytes

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18
Q

Management of warts?

A

Usually disappear (months-2 yrs) without treatment and scarring.

Consider active management if painful, unsightly or persistent.

  • Topical salicylic acid (keratolytic) gel – daily for 12 weeks
  • Cryotherapy (not in small children as is painful) – once every 3-4 weeks for up to 4 cycles.
  • Duct tape occlusion (leave inplace for 6 days at a time for up to 8 weeks – probably placebo)
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19
Q

What is a BCC? Risk factors?

A

Slow growing locally invasive malignant tumour of the epidermal keratinocytes. Rarely metastasises.

  • UV exposure
  • History of severe or frequent sunburn in childhood
  • Skin type I (always burns, never tans)
  • Age
  • Male sex
  • Immunosuppression
  • Previous hx of skin cancer
  • Genetic predisposition
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20
Q

Presentation and complications of BCC?

A
  • Pearly nodule
  • Rolled telangiectatic edge on the face or a sun exposed site
  • +/- central ulcer (necrotic or ulcerated centre – rodent ulcer)
  • Most common on head and neck

Local tissue invasion and destruction if left untreated

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21
Q

Management of BCC?

A
  1. Surgical Excision
    • 1st line - allows histological examination
    • Mohs micrographic surgery - for high risk recurrent tumours
  2. Other
    • Cryotherapy, radiotherapy, photodynamic therapy
  3. Topical
    • Imiquimod or fluorouracil - for superficial lesions at low-risk sites
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22
Q

Definition of SCC? Risk factors?

A

Locally invasive malignant tumour of the epidermal keratinocytes or its appendages, which has the potential to metastasise

  • Excessive UV exposure
  • Pre-malignant skin conditions (actinic keratosis)
  • Immunosuppression
  • Chronic inflammation (leg ulcers, wound scars)
  • Genetic predisposition
  • HPV
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23
Q

How does SCC present? Complications?

A

Persistently ulcerated or crusted (keratotic) lesion often on sun-exposed sites

  • Local invasion and metastasis
  • High risk if
    • Near lip, ear or non-sun exposed site (sole, perineum),
    • Immunosuppressed, large etc.
24
Q

Management of SCC?

A
  • Surgical excision – treatment of choice.
  • Mohs micrographic surgery – may be necessary for ill-defined, large, recurrent tumours.
  • Radiotherapy – for large, non-resectable tumours.
25
Q

Definition of melanoma?

A

Invasive malignant tumour of the epidermal melanocytes which has the potential to metastasise

26
Q

Risk factors for melanoma?

A
  • Excessive UV exposure
  • Skin type I
  • History of multiple/atypical moles
  • Personal/family history of melanoma
  • Large numbers of moles
  • 3 or more episodes of sunburn
27
Q

How do most melanomas arise?

A

. Most arise de novo, not in pre-existing melanocytic naevi.

28
Q

Types of melanoma?

A
  1. Superficial spreading
  2. Nodular
  3. Lentigo Malinga
  4. Acral Lentinginous
29
Q
A

Superficial Spreading

Common on the lower limbs, in young and middle aged adults; related to intermittent high intensity UV exposure

30
Q
A

Nodular

Common on the trunk, in young and middle aged adults; related to intermittent high-intensive UV exposure

Ulceration –> bad sign

31
Q
A

Lentigo Malinga

Common on face in elderly population; related to long term cumulative UV exposure

(Melanoma in situ - not yet invasive. When it gets a lump in the middle it becomes lentigo maligna melanoma)

32
Q
A

Acral Lentinginous

Common on the palms, soles and nail beds, in elderly population; no clear relation with UV exposure.

(Acral = hands and feet, lentiginous = flat patch)

Subungual = under the nail

33
Q

Signs of melanoma?

A

ABCDE Symptoms Criteria

  • Asymmetrical shape
  • Border irregularity or blurring
  • Colour irregularity (black, brown, blue, pink)
  • Diameter >6mm
  • Evolution of lesion (e.g. change in size and/or shape)
  • Symptoms (e.g. bleeding, itching).

Others = ulcerated, inflamed

34
Q

Chance of recurrence of melanoma?

A

Based on Breslow thickness

  • <0.76mm – low risk (95% 5 year survival)
  • 0.76mm-1.5mm – medium risk
  • >1.5mm – high risk.
35
Q

What is a venous ulcer and how is it caused?

A
  • Venous HTN from incompetent valves –> superficial varicosities and skin changes (dermatosclerosis)
  • Minimal trauma causes ulcers (usually over medial malleolus)
36
Q

Appearance of arterial ulcers?

A

Punched out

37
Q

Risk factors for venous ulcers?

A

Varicose veins, venous insufficiency, poor calf muscle function, arterio-venous fistulae, obesity, leg fracture

38
Q

Management of venous ulcers?

A

Graded Compression Bandaging

  • Promotes venous return, reduced venous pressure –> healing
  • Do doppler first to exclude PAD

Infected ulcers

  • Systemic abx - avoid topical as they increase resistance and contact dermatitis

General

  • Analgesia
  • If no healing in 3 months, investigate further (biopsy for malignancy)
39
Q

Prevention of recurrence of venous ulcers once healed?

A

compression stockings, skin care, leg elevation, calf exercises, good nutrition

40
Q

What is actinic keratosis?

A
  • Pre-malignant crumbly yellow-white scaly crusts on sun-exposed skin from dysplastic intra-epidermal proliferation of atypical keratinocytes.
  • Prevalence = 52% at 70 yrs old.
41
Q

What is a keloid scar?

A

Exaggerated scarring (from excess collagen production, especially type III) to beyond the confines of the initial wound and can appear progressively and after a delay

42
Q

What is a ganglion cyst and where do they occur?

A
  • Fluid filled lump associated with a joint or tendon sheath
  • Usually back of wrist or front of wrist
  • No further symptoms usually - can cause pain, numbness, carpal tunnel syndrome.
43
Q

What is this?

A

Congenital Naevus

  • Painless large dark coloured mole - scalp or trunk of body.
  • Increased risk of skin cancer as adults.
44
Q

>6 cafe au lait spots?

A

?neurofibromatosis

45
Q

What is port wine stain associated with?

A

Sturge weber syndrome: seizures, learning disorders, glaucoma

46
Q

What is this?

A

Kaposi’s Sarcoma

  • Abnormally vascularised spindle cell tumour derived from capillary endothelial cells.
  • Cause = HHV-8 (herpes hominis virus)
  • Incidence decreasing due to HAART
  • Purple papules or plaques on the skin and mucosa of any organ. Metastasises to nodes.
47
Q

Skin signs in diabetes?

A
  • Flexural candidiasis
  • Necrobiosis lipoidica
    • Waxy, shiny yellow areas on shins
  • Acanthosis nigricans
  • Granuloma annulare
    • Ring of small pink, purple or skin-coloured bumps. It usually appears on the back of the hands, feet, elbows or ankles
  • Folliculitis
48
Q

Skin sign of coeliac disease?

A

Dermatitis Herpetiformis

  • Itchy ‘burning’ blisters on elbows, scalp, shoulders, ankles
49
Q

Skin signs in IBD?

A

Erythema Nodosum

  • Tender ill-defined nodules on shins
  • Also sarcoid, drugs, TB, strep

Pyoderma Gangrenosum

  • Rapidly growing, very painful, tender red/blue overhanging necrotic edge.
  • Leg, abdomen, face
50
Q

What does erythema multiforme look like? Causes?

A
  • Erythematous well defined lesions on extensor surfaces of peripheries, palms, soles
  • Evolve into target lesions
  • Major form has systemic upset and severe muscoal involvement

Causes = herpes simplex, mycoplasma, CMV, drugs

Resolves spontaneously in 4 weeks

51
Q

What is erythema migrans? Treatment?

A

Lyme disease - red ring lasting weeks to months

Abx treatment = doxy, amox or cefuroxime

52
Q

Examples of cutaneous vasculitis?

A
  • Palpable purpura (e.g. on legs)
  • Nodules
  • Painful ulcers
  • Livedo reticularis

Caused by: idiopathic, PAN, HSP, GPA

53
Q

What is Livedo Reticularis?

A

Non-blanching vague pink-blue mottling, most often on legs.

Caused by connective tissue disease, vasculitis, cholesterol emobil and hyperviscosity states

SLE!!

54
Q
A
55
Q

Keratoanathoma?

A
  • Rapidly growing tumour (weeks) - keratinizing squmous cells, resolving spontaneously (3 months) if untreated
  • Central part of face, hand, forearm
  • Incidence related to sun exposure
  • Need to treat as if SCC