DERM Flashcards
Functions of the skin
1. Barrie rot infection 2> thermoregulation 3. Protection against trauma 4. Protection against UV 5. Vit D syntehsis 6. Regulate H20 loss
pH of the skin
5.5
Why is the skin pH 5.5
Allows proteases on the skin to do desquamination
What is the stratum corneum
Made of corner-desmosomes and desmosomes
What are cornel-desmosomes
Adhesion molecules that keep corneocytes together
Describe the layers of the skin
- Stratum lucidium
- Granulosum
- Spinous
- Basale
What nerve endings are found in the dermis
Meissner’s corpuscules - light touch
2. Pacinian corpuscle (vibration)
Role of keratinocytes
Produce keratin as a protective barrier
Role of Langerhans cells
Present antigens and activate T cells
Role of merkel cells
Specialised nerve endings for sensation
Common causes of itch with rash
- URTICARIA (hives)
- ATOPIC ECZMA
- Psoriasis
- Scabies
Common causes of itch with no rash
- Renal failure
- Jaundice
- Iron deficiency
- Lymphoma (hodgkin’s)
- Polycythaemia
- Pregnancy
- Drugs
- Diabetes
- Cholestasis
What is acne
Expansion and blockage of hair follicle and inflammation
Most common variant of acne
Acne Vulgaris
Pathophysiology of acne
- Hypercornfiictaion causes narrowing of hair follicle
- Increased sebum production
- Sebum is trapped which narrows follicle further
- Sebum stagnates at pit of follicle where there is no oxygen
- Anaerobic conditions allow propionibacterium acne to multiply
- P. acne breaks down triglycerides in sebum into free fatty acids = irritation, inflammation and attraction of neutrophils
- Pus formation as attract neutrophils come into the area
Whitehead vs blackhead
White - closed comedones
Black - open comedones
Clinical presentation of acne
- Whiteheads
- Blackheads
- Skin coloured papule (red spots)
- Inflammatory lesions when closed wall of comedones rupture
- Pustules (yellow spots)
- Nodules (large red bumps
Diagnosis of acne
- Skin swabs for culture
2. Hormonal test in females
Treatment of acne
- BENZOYL PEROXIDE
- CLINDAMYCIN GEL
- TAZAROTENE GEL (topical retinoid)
How does Benzoyl peroxide work
Increases skin turnover
Clears pores and reduces bacterial count
Causes dryness due to kertaolytic effect
How do topical retinoids work
Inhibit formation and reduce number of micromedones
Severe acne treatment
- ORAL DOXYCYCLINE
- ORAL MINOCYCLINE
HORMONE TREATMENT with ORAL CO-CYPRINDIOL (anti-androgen suppresses sebum productioN)
What is eczema/dermatitis
Breakdown of skin due to thinning of stratum corneum - increased risk of inflammation
What is endogenous eczema
Hypersensitivity caused (food allergies)
What is exogenous eczema
Contact dermatitis due to chemicals, sweat and abrasives
Pathophysiology of eczema
- Damaged filaggrin
2. CD4 lymphocytic activation = inflammation
Role of filaggrin
Skin barrier protein
Clinical presentation of eczema
- face and flexure surfaces of limbs
- Itchy, erythematous and scaly patches
- Dryness of skin
- Very acute lesions
RECURRENT STAPHYLOCOCCUS AUREUS INFECTIONS
Diagnosis of eczema
- Atopic dermatitis:
High serum IgE
Itchy skin for 6 months
PULS: History of involvement of skin creases Asthma or hay fever Dry skin history Childhood
Treatment of eczema
- Eductaion
- Avoid allergens
- Keep nails short
- E45 CREAM
- Topical corticosteroids
- Second line: Topical calcineurin inhibitors
How does E45 work (EMOLLIENT THERAPY)
- Traps moisture in skin to increase hydration and acts as barrier to water loss
Natural moisturising factor in corneocytes is depleted in eczema
How often is E45 applied
Every 4hours / 3 - 4 times a day
What topical corticosteroids are given as first line treatment for eczema
- CLOBETASOL PROPIONATE
- FLUCINONIDE
- CLOBETASOL BUTYRATE
- HYDROCORTISONE
used for inflamed skin
What topical calcineurin inhibitors are given
PIMECROLIMUS or TACROLIMUS ointment
How do topical calcineurin inhibitors work
- Inhibit IL 2 which reduces inflammation and do not cause skin atrophy
3rd line treatment for eczema
- CICLOSPORIN
- AZOTHIOPRINE
- ORAL PREDNISOLONE
- FLUCLOXACILLIN
- PHOTOTHERAPY with UV A
- CHLORPHENAMINE
What is psoriasis
Hyper proliferation of keratinocytes + inflammatory cell infiltration
What aged people are effected by psoriasis
ADULTS
What environmental triggers cause psoriasis
- Infection by group A strep
- Lithium
- UV
- Alcohol
- Stress
Pathophysiology of psoriasis
- T cell activation = up regulation of INF gamma, IL1,2,8
2. Increased uncontrolled proliferation of keratinocytes
Clinical presentation of psoriasis
- Pitting and onycholysis (separation of finger nail from nail bed)
Clinical presentation of chronic plaque psoriasis
- Disc shaped salmon-pink-silvery plaques on exterior surfaces of elbows and knees
- Plaques on hair margin
- Thickened epidermis
- New plaques at skin trauma sites
How is chronic plaque psoriasis treated
- E45
- CALCIPQOTRIOL CREAM (topical vit D analogues)
- HYDROCORTISONE CREAM (topical corticosteroids)
- TAZAROTENE GEL (topical retinoid)
- UV B
- COAL TAR
- DITHRANOL CREAM (anti-mitotic)
- ——SEVERE——-
1. UV A
2. DMARD (METHOTREXATE and FOLIC ACID)
3. CICLOSPORIN
Clinical presentation of flexural psoriasis
- Red, glazed non-scaly plaques
2. Confined to flexures (groin, natal cleft and sub-mammary areas)
How is flexural psoriasis treated
- HYDROCORTSIONE - causes atrophy
2nd line: CALCIPQOTRIOL CREAM (irritating so don’t use for face)
Clinical presentation of Guttate psoriasis
- Trunk, upper arms and legs
- Small circular and oval plaques afterr 2 weeks of strep sore throat
- CHILDREN
treatment of GUTTATE PSORIASIS
- HYDROCORTISONE or CLOBETASOL UTYRATE
- UV B
- Coal tar
Clinical presentation of Palmoplantar psoriasis
- Thickening of palms and soles
Treatment of palmoplantar psoriasis
- Emollients
- SALICYLIC ACID
- FLUCINONIDE
- UV A
- ORAL ACITRETIN (anti-proliferative)
- Anti-TNF biologics (IV INFLIXIMAB or IV ADALIMUMAB)
Define venous skin ulcers
Loss of skin below knee on leg or foot that takes 2 weeks to heal
What causes venous skin ulcers
Sustained venous hypertension in superficial veins
What causes sustained venous hypertension
- Incompetent valves in deep veins
- Previous DVT
- Atherosclerosis
- Vasculitis (RA and SLE)
Risk factors for venous skin ulcers
DVT
Pathophysiology of venous skin ulcers
- Increased pressure causes extravasation of fibrinogen through capillary walls giving his ego perivascular fibrin deposition = poor oxygenation of surrounding skin
Clinical presentation of venous skin ulcers
- Sloping and gradual edges
- Large, irregular ulcer
- Minimal pain
- Oedema of lower leg
- Venous eczema
- Brown pigmentation from haemosiderin
- Varicose veins
- Pulses present
- Warm skin
Diagnosis of venous skin ulcers
- Ankle brachial pressure index is normal
2. Doppler ultraosund
Treatment of venous skin ulcers
- High compression 4 layered bandage
- Leg elevation to reduce hypertension
- Antibiotics
- IBUPROFEN
- Support stockings for life
What are arterial ulcers
Present as punched-out, painful higher up the leg or on the feet
Risk factors for arterial ulcers
- Atherosclerosis
- Smoking
- Hypercholesterolaemia
- Diabetes Mellitus
Clinical Presentation of arterial ulcers
- Punch-out ulcers higher up on the leg or on feet
- Pain is worse when elevated
- Leg is cold and pale
- Ulcer is small and sharply defined with necrotic base
- Shiny pale skin and loss of hair
- Absent peripheral pulses
- Arterial bruits (murmurs caused by turbulent blood flow
- NO OEDEMA
Diagnostics of arterial ulcers
- Doppler Ultrasound
2. ABPI
Treatment of arterial ulcers
- Cover and clean ulcer
- Analgesia (IBUPROFEN)
- Vascular reconstruction
- NEVER USE COMPRESSION BANDING
What is a neuropathic ulcer
Seen over pressures of the feet which are painful
DIABETES and LEPROSY
Clinical presentation of neuropathic ulcer
Warm skin and normal peripheral pulses
Treatment of neuropathic ulcer
- Keep ulcer clean and remove pressure or trauma from affected areas
- Correctly fitting shoes and specialist podiatrist help for diabetics
What is a vasculitic ulcer
- Blood vessels causing endothelial damage
How is cutaenosu vasculitis diagnosed
SKINBIOPDY
What is Leucocytoclastic vasculitis
- Appears on the lower legs as symmetrical palpable purport
What causes lecuocytoclastic vasculitis
- Drugs
- Infection
- Inflammatory disease
- Malignant disease
Clinical presentation of leucocytoclastic vasculitis
- Haemorrhagic papules
- Pustules
- Nodules
- Plaques
- NON BLANCHING PURPURIC LEISIONS
- Pyrexua and arthralgia
Treatment of leucocytoclastic vasculitis
- Analgesia
- Support stocking s
- DAPSONE or PREDNISOLONE
What kind of cancer is skin cancer
SQUAMOUS CELL CARCINOMA of the keratinocytes
Why is SCC more aggressive than BCC
Metastases to the lymph nodes
What is Bowen’s disease
SCC confined to the epidermis
Risk factors of SCC
- UV
2. Chronic inflammation
Clinical presentation of SCC
- Sun-exposed sites
- Lesions are keratotic that may ulcerate
- Grow very rapidly
- Ulcerates lesions on lower lip or ear ar more aggressive
5
Treatment of SCC
- Surgical excision with margin of 5mm
2. Raiodtherapy
Where are Basalc ell carcinomas found
Elderly on head and neck
What is a rodent ucler
Ulceration of basal cell carcinoma
What is basal cell carcinoma
Tumour of basal keratinocytes
Risk factors of BCC
- UV
- Skin type I
- Ageing
What is skin Type I
Skin that burns and doesn’t tan
Clinical presentation of BCC
- Border of ulcerated lesion raised with pearly appearance
- Slowly enlarging, shiny nodule on head and neck area which bleeds following minor trauma and does not heal
- Slowly causes local tissue destruction if not treated
How is BCC treated
- Surgically excised to ensure clear and adequate tumour margins
- Cryotherapy + Photodynamic therapy
- Radiotherapy for those who don’t tolerate surgery
What is malignant melanoma
- Malignant tumour of melanocytes
Age effected by malignant melanoma
Younger patients
Risk factors for malignant melanoma
- UV exposure
- Red hair
- High density freckles
- Skin type I
- Atypical moles
- Multiple melanocytic nave
- Sun sensitivity
- Immunosuppression
- Family History
- Pale Skin
Clinical Presentation of Malignant Melanoma
- Men - Back
- Women - Lower legs
- Very dark colour, black
- ABCDE:
A - Asymmetrical shape
B - Border irregularity
C - Colour Irregularity
D - Diameter > 6
E - Elevation/Evolution (change of lesion) - Itching
- Inflammation, crusting or bleeding
Types of melanomas
- Superficial Spreading
- Lentigo maligna (on face)
- Acral (restricted to palms and soles
Differential diagnosis of melanomas
- Benign pigmented naevus
- Seborrhoeic wart
- Pyogenic granuloma
How is Malignant Melanoma treated
- Surgical excision in early stages
2. Removal of regional lymph nodes, isolated limb perfusion, radiotherapy, immunotherapy and chemotherapy
Metastases of malignant melanoma
- Lung, Liver, CNS
Prognosis of Malignant Melanoma
- Thin lesions (<1mm) have best prognosis
- If over 60 then lower 5 year survival
- Generally there is a female advantage in prognosis
- Ulceration
- Poor prognosis if present on trunk vs limbs
What is cellulitis
- Bacterial Infection of the deep sub-cutaneous tissues
Where is cellulitis commonly seen
Lower extremities
What causes cellulitis
- STREPTOCOCCUS PYOGENES (Group A beta-haemolytic)
2. Staph Aureus
Risk factors for cellulitis
- Lymphedema
- Leg Ulcer
- Immunosuppression
- Traumatic wounds
- Athletes for
- Leg Oedema
- Obesity
Clinical Presentation of cellulitis
- Local inflammation (spreads to proximal body)
- Hot erythema in affected area
- Poorly demarcated margins, swelling, warmth and tenderness
- Blister if oedema is present
- FEVER
Diagnosis of cellulitis
- Clinical
- Skin Swabs negative
- Serological testing for streptococcal infection (antistreptolysin O titre)
How is cellulitis treated
- ORAL PHENOXYMETHYLPENICILLIN or ERYTHROMYCIN if allergic to penicillin
- IV for 3-5 days of antibiotics if infection is widespread
- PHENOCYMETHYPENICILLIN ORALLY twice a day for prophylaxis
What is Necrotising Fasciitis
- Deep-seated infection of the subcutaneous tissue causing fulminant and spreading destruction of fascia and fat which spares the skin initially
What is type I necrotising fasciitis
- Caused by a mixture of aerobic and anaerobic bacteria following abdo surgery or in diabetics
What is type II necrotising fasciitis
- Caused by group A beta-haemolytic streptococci
Risk factors for type II necrotising fasciitis
- Abdo surgery
2. Immunosuppression
Clinical presentation of type II necrotising fasciitis
- Severe pain out of proportion to the skin findings at initial site of infection
- Infection rapidly spreads along tissue planes causing erythema and pain + crepitus
- Patients with fever, toxicity and pain that is out of proportion to skin findings - necrotising fasciitis should be suspected
- Multi-organ failure is common and mortality is high
Diagnostics of necrotising fasciitis
- Soft tissue gas seen on X-ray
- Raised CRP
- Raised WCC
4
Treatment of necrotising fasciitis
- IV BENZYLPENICILLIN and IV CLINDAMYCIN
- IV METRONIDAZOLE for widespread IV antibiotics if unknown cause
- Surgical debridement or amputation
Adverse effects of corticosteroids
- Skin thinning, telangiectasia and contact dermatitis
- Perioral dermatitis and acne on the face
- Withdrawal
Adverse effects of Emollients
Greasiness of skin and exacerbates acne on face
Name two kertolytics
ALLANTOIN and SALICYLIC ACID
Role of keratolytics
Softens skin and causes cells of epidermis to shed more rapidly, opening clogged pores
Adverse effects of keratolytics
Hypersensitivity and chemical burns
2. Sun protection needed
When should retinoids be avoided
SEVERE TERATOGEN