4. Dermatology A Flashcards
Main function of skin
- Barrier and protection - epidermis
- Strength and flexibility - dermis
- Fat and insulation - SC tissue
What is found in epidermis?
Stratum corneum is outside layer which is thickest on palms and soles of feet
Langerhan cells are found here - immune function
What is found in the dermis?
- Made of collagen, elastin and fibrillin
- Nerves
- Glands
- Hair follicles
- Blood vessels
Outline psoriasis from epidermis
Increased cell turnover
Hyperproliferation/thickening of epidermis
Causes scaly plaques
Dilation of BV causes erythema
What diseases affects flexural areas?
Eczema
What can affect mucus membranes?
Lichen planus with lace-like reticular pattern
What is the first line treatment for mild/moderate acne?
Topical benzoyl peroxide + topical adapalene
Topical benzoyl peroxide + topical clindamycin
Topical tretinoin + topical clindamycin
What is the treatment for moderate/severe acne?
Either of first 2 options from mild/moderate OR
Topical adapalene + topical benzoyl peroxide + oral doxycycline/oral lymecycline
Topical azelaic acid + oral doxycycline/oral lymecycline
Can use COCP instead of oral abx
Isotretinoin is reserved for secondary care
What is SCC?
- Common variant skin cancer
- Arises from squamous cells -flat, thin cells found in dermis
- Rapidly expanding, ulcerated nodules
- Some bleed
What are the risk factors of developing a squamous cell carcinoma?
Sun exposure
Tanning beds
Immunosupression
Genetic conditions eg Xeroderma pigmentosum
How is SCC managed?
- Surgical excision with 4mm margin (6mm in high risk lesions)
- Mohs micrographic surgery - tissue removed and examined under microscope in real time to ensure all cancerous cells are removed
- Radiotherapy
- Curretage and cautery
- Topical 5-fluorouracil or imiquimod
- Cryotherapy
When is cryotherapy used for a SCC?
If there is a low risk of it being cancerous e.g. flat and superficial
Safety netting for SCC
- If increasing in size rapidly and invading surrounding structures
- Lumps in neck
What is BCC?
- Most common type of non-melanoma skin cancer worldwide
- Exposure to UV light
- More risk if fairer and easily burn
- Can vary greatly in appearance
- Curable in most cases
- Rarely spread
Management for BCC?
- Wide local excision
- Cryotherapy
- Iquimoid cream
- Curretage
- Mohs micrographic surgery
- Radiotherapy
Safety netting for BCC
- 50% of people will develop 2nd BCC within 3yrs of first
- Prevent further lesions by preventing sunburn
- At increased risk of other cancers eg melanomas
- Do regular self skin checks and annual skin checks
- Look for change in shape, colour, size 7mm or more, irregular
How does measles present?
- Intial cough and fever - URTI symptoms then rash
- Rash starts behind ears and on face
- VERY infectious
- Check for Koplik spots in buccal mucosa
- Only affects unvaccinated usually
What does a measles rash look like?
Erythematous maculopapular rash, non pruiritic
Where to refer for suspected melanoma?
2 week wait for pigmented lesion clinic
How does ringworm appear?
Round
Central clearing
What is the treatment for ringworm?
- Topical clotrimazole or miconazole if isolated OTC
- Topical hydrocrotisone 1% if lots of inflammation
- Oral terbinafine if extensive
How long do fungal infections take to resolve?
- Skin 3-4 weeks
- Nails can take 6 weeks-6 months of treatment
What can be a cause of recurrent thrush?
Lichen sclerosis
Skin conditions that cause pruritis?
Scabies
Uraemia
Lichen planus
Lichen sclersosis
Nodular prurigo
Eczema
Bites
What is Pompholyx?
Eczema and blisters
Pityriasis rosea vs versicolour
Versicolour is fungal infection
Need antifungals
Rosea is just self limiting
Lymes disease - presentation and treatment
Target lesion
After walking in long grass that deer are found - tick bite
3 weeks of Doxycycline
Nappy rash vs candida
- Nappy rash commonly caused by ammonia in urine irritating skin
- Spared skin sections which do not touch ruine
- Fluffier edges compared to candida
What is psoriasis which is just back droplets and not plaques?
Guttate psoriasis - 1/3 have no FH and do not go on to develop plaques
How is psoriasis managed?
PSORIASIS
Phototherapy
Salicylic acid
Ointments (emolients)
Retinoid (oral acitretin)
Calcineurin Inhibitors
Vitamin A
Steroids
Immunosupressors e.g. methotrexate
Sun (vitamin D analogues)
What scoring is used for psoriasis?
PEST score
What does psoriasis often come along with?
Dactilytis- sausage finger
Achilles tendonitis
Plantar fasciitis
List steroids in order of potency
- Hydrocortisone
- Eumovate or Betnovate RD- clobetasone butyrate or reduced dose betamethasone valerate 0.025%
- Betnovate -betamethasone valerate 0.1%
- Dermovate - clobetasol propionate 0.05%
