Dermatology Flashcards
Definition of acne? Causes?
Inflammatory disease of the pliosebaceous follicle.
Causes
- Hormonal (androgens)
- Increased sebum production
- Abnormal follicular keratinisation
- Bacterial colonisation
- Inflammation
Signs/symptoms of mild and moderate/severe acne?
Mild
- Non-inflammatory lesions
- Open and close comedones (blackheads and whiteheads)
Moderate/Severe
- Inflammatory lesions
- Papules, pustules, nodules and cysts
- Affects face +/- torso
Management of Acne?
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
Mode of action of isotretinoin? Side effects?
Reduced sebum production and reduced pituitary hormones
- Teratogenic (contraception during and 1 month after)
- Skin and mucosal dryness
- Depression
Definition of eczema?
Inflammation characterised by papules and vesicles on an erythematous base
Presentation of eczema?
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
Complication of eczema (secondary infection)?
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.
General advice in eczema?
- 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)
Medical management of eczema?
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
Potency of topical steroids?
Mild = 1% hydrocortisone
Moderate = 2.5% hydrocortisone
Strong = betnovate/dermovate
Definition of psoriasis? Precipitating factors?
Chronic inflammatory skin disease due to hyperproliferation of keratinocytes and inflammatory cell infiltration.
- Trauma (koebner phenomenon)
- Infection (tonsilitis)
- Drugs/alcohol
- Stress
Types of psoriasis?
- Chronic plaque (most common)
- Guttate (raindrop lesions)
- Seborrhoeic (naso-labial and retro-auricular)
- Flexural (body folds)
- Pustular (palmar-plantar)
- Erythrodermic (total body lesions)
Symptoms and signs of psoriasis?
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
General advice/management of psoriasis?
- 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)
Management of psoriasis?
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
Side effects of non-biologic therapies for psoriasis?
-
Methotrexate
- Once a week. Avoid in young due to risk of hepatic fibrosis long term.
- Monitor FBC/LFT
-
Ciclosporin
- ↑BP and renal dysfunction
-
Acitretin (oral retinoid)
- Teratogenic, dry skin, ↑lipids, glucose and LFTs
What are warts? What causes them?
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
Management of warts?
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)
What is a BCC? Risk factors?
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
Presentation and complications of BCC?
- 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
Management of BCC?
-
Surgical Excision
- 1st line - allows histological examination
- Mohs micrographic surgery - for high risk recurrent tumours
-
Other
- Cryotherapy, radiotherapy, photodynamic therapy
-
Topical
- Imiquimod or fluorouracil - for superficial lesions at low-risk sites
Definition of SCC? Risk factors?
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
How does SCC present? Complications?
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.
Management of SCC?
- Surgical excision – treatment of choice.
- Mohs micrographic surgery – may be necessary for ill-defined, large, recurrent tumours.
- Radiotherapy – for large, non-resectable tumours.
Definition of melanoma?
Invasive malignant tumour of the epidermal melanocytes which has the potential to metastasise
Risk factors for melanoma?
- 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
How do most melanomas arise?
. Most arise de novo, not in pre-existing melanocytic naevi.
Types of melanoma?
- Superficial spreading
- Nodular
- Lentigo Malinga
- Acral Lentinginous
Superficial Spreading
Common on the lower limbs, in young and middle aged adults; related to intermittent high intensity UV exposure
Nodular
Common on the trunk, in young and middle aged adults; related to intermittent high-intensive UV exposure
Ulceration –> bad sign
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)
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
Signs of melanoma?
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
Chance of recurrence of melanoma?
Based on Breslow thickness
- <0.76mm – low risk (95% 5 year survival)
- 0.76mm-1.5mm – medium risk
- >1.5mm – high risk.
What is a venous ulcer and how is it caused?
- Venous HTN from incompetent valves –> superficial varicosities and skin changes (dermatosclerosis)
- Minimal trauma causes ulcers (usually over medial malleolus)
Appearance of arterial ulcers?
Punched out
Risk factors for venous ulcers?
Varicose veins, venous insufficiency, poor calf muscle function, arterio-venous fistulae, obesity, leg fracture
Management of venous ulcers?
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)
Prevention of recurrence of venous ulcers once healed?
compression stockings, skin care, leg elevation, calf exercises, good nutrition
What is actinic keratosis?
- 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.
What is a keloid scar?
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
What is a ganglion cyst and where do they occur?
- 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.
What is this?
Congenital Naevus
- Painless large dark coloured mole - scalp or trunk of body.
- Increased risk of skin cancer as adults.
>6 cafe au lait spots?
?neurofibromatosis
What is port wine stain associated with?
Sturge weber syndrome: seizures, learning disorders, glaucoma
What is this?
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.
Skin signs in diabetes?
- 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
Skin sign of coeliac disease?
Dermatitis Herpetiformis
- Itchy ‘burning’ blisters on elbows, scalp, shoulders, ankles
Skin signs in IBD?
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
What does erythema multiforme look like? Causes?
- 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
What is erythema migrans? Treatment?
Lyme disease - red ring lasting weeks to months
Abx treatment = doxy, amox or cefuroxime
Examples of cutaneous vasculitis?
- Palpable purpura (e.g. on legs)
- Nodules
- Painful ulcers
- Livedo reticularis
Caused by: idiopathic, PAN, HSP, GPA
What is Livedo Reticularis?
Non-blanching vague pink-blue mottling, most often on legs.
Caused by connective tissue disease, vasculitis, cholesterol emobil and hyperviscosity states
SLE!!
Keratoanathoma?
- 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
