Revision List Dermatology Flashcards
Pathophysiology of acne?
- Hair follicle narrow - hypercornification
- Increase sebum production –> greasy skin trapped in narrow follicles.
- Sebum stagnates at pit of follicle - no O2
- Proprionibacterium acnes –> break down triglycerides in sebum to 3FA
- Irritation, inflammation and attraction of neutrophils
- Pus formation and further inflammation
Clinical features of acne?
- Closed comedones
- Open comedones
- Papules
- Pustules
Differential diagnosis of acne
- Acne rosacea
- Milia
- Follliculitis
- Perioral dermatitis
Treatment of acne vulgaris?
- Keep face clean
- Benzoyl peroxide gel/cream
- Topical Abx: clindamycin /erythromycin gel
- Topical retinoids: tazarotene gel
Treating severe acne?
- oral tetracycline - 4 month min, contraindicated in pregnancy and children
- Hormonal treatment: anti-androgen Tx –> suppress sebum production
e. g. oral co-cyprindiol
What is eczema?
Describe common group of inflammatory skin diseases - breakdown of skin due to thinning of stratum corneum –> risk of inflammation
Clinical presentation of eczema?
- Face and flexor surfaces of arm
- Itchy, erythematous and scaly patches
- Dry skin persist throughout life
Clinical presentation of infancy eczema?
- Face
2. Scalp
Clinical presentation of bacterial infection in eczema?
- Crusting
- Weeping
- Pustulation
- Cellulitis
Sudden worsening
Clinical presentation of eczema herpeticum?
- Rapidly worsening painful eczema
- Clustered blisters
- Punched out erosions
- Fever, lethargy, distress
Diagnostic criteria for eczema?
Clinical diagnosis
- High serum IgE
- Must have itchy skin condition in past 6 months
Also 3 of more:
- History of itching in skin creases
- History of asthma/hay fever
- History of generally dry skin
- Onset in first 2 years of life
Treatment of eczema?
- Education - nails short, skin hydrated
- Emollient therapy e.g. E45 cream
- 1st line: topical corticosteroids
- 2nd line: topical calcineurin inhibitors
How do emollients work to treat eczema?
Occlusive emollients trap moisturise in skin , transiently increase in hydration
Artificial permeability barrier –> form above stratum corneum –> prevent water loss between corneocytes
Topical corticosteroids staging for eczema?
- Mild - hydrocortisone –> face/flexures
- Moderate: clobetasone butyrate
- Potent for severe eczema: fluocinonide
- Very potent: clobetasol propionate
Topical calcineurin inhibitors how they work?
Inhibit calcineurin which induce transcription factor –> for many interleukins e.g. IL2 –> activate in cells –> induce production of cytokines
How to treat moderate/severe/non-responsive eczema?
- Oral/ immune modulators:
- ciclosporin - calcineurin inhibitor
- azathioprine - aware of immunosuppression - Oral steroids - prednisolone
- Abx - flucloxacillin
- Phototherapy with UVA
- Anti-histamines e.g. chlorphenamine
Squamous cell skin cancer?
Locally invasive malignant tumour if the squamous keratinocytes
- more aggressive than basal cell carcinoma + higher metastatic potential
What is Bowen’s disease?
In situ SCC confined to epidermis
Risk factors for SCC?
UV exposure
Chronic inflammation e.g. wound scar and immunosuppression
Clinical presentation of SCC?
- On sun exposed sites in later life
- Grow v rapidly
- Ulcerate lesions on lower lip/eat = more aggressive
- Examination of regional lymph nodes
Treatment of SCC
Surgical excision
Radiotherapy
Basal Cell Carcinoma
Most common malignant skin cancer
Tumour of basal keratinocytes
Risk factors of BCC?
- UV exposure
- Skin type 1
- Ageing
Clinical presentation of BCC?
Later life presentation
Less aggressive and metastatic than SCC
Border of ulcerated ulcers - raised with pearly appearance
Slow enlarging shiny nodule on head and neck area –> bleeds and doesn’t heal following minor trauma
Rodent ulcer
