Dermatology Flashcards
What are the layer of the skin?
- epidermis
- dermis
- hypodermis
What is the largest organ of the body?
The skin (1.5-2.0m^2)
What is the function of skin?
- anatomical barrier
- heat regulation
- sensory input
- storage for lipids and water
- drug absorption and waste excretion
How does oily skin differ from ‘normal’ skin?
- more secretion from sebaceous glands (sebum)
- more bacterial colonisation
- skin becomes heavier and thicker
- more risk of pore black age
- more spots and pimples
- less likely to wrinkle
What are comedones?
Blackheads
- build up of keratin and sebum
What are examples of bacterial infections of the skin?
- acne
- impetigo
- furuncles and carbuncles
- erysipelas
What are furuncles?
Pockets filled with pus
- caused by staph aureus
- red painful and swollen
Who is most likely to suffer from acne?
teenagers
What are the causes of acne?
- follicular sensitivity to testosterone
What can make acne worse?
- contraceptive pills (progesterone)
- systemic steroid treatment
- anticonvulsant drugs
How can acne be managed locally?
- reduce excess skin oil (using cleanser)
- benzoyl peroxide
- retinoids
- antibiotic lotions
If local treatments for acne fail, what systemic management is used?
- antibiotics (tetracycline based)
- retinoids (isotretinoin)
- hormone manipulation (anti-androgens)
What microorganism causes Erysipelas?
streptococcus pyogenes
How is erysipelas managed?
- oral/IV antibiotics
What can erysipelas progress to?
- necrotising fasciitis
- septic shock
What is Impetigo?
Highly infection skin disease caused by
- staphylococcal
- streptococcal
Has a crust red blister appearance
What are examples of viral skin infection?
- herpes simplex
- shingles
- warts
- molluscum contagiosum
What can cause activation of the Herpes simplex virus?
Trauma
- physical
- chemical
- UV light
How is Herpes Simplex treated?
Aciclovir
What causes Molluscum Contagiosum?
MCV (pox virus)
What causes warts?
Human Papilloma Virus (types 1-3)
How are warts treated?
- keratolysis
- cryosurgery
- excision
What are examples of fungal skin infection?
- Athletes foot
- Ringworm
- Intertrigo
How can athletes foot be prevented?
- keep skin dry
- keep skin damage free
How is athletes foot treated?
Miconazole (topical)
What is intertrigo? How is it treated?
Fungal infection due to chafing in moist body folds.
Treat with topical antifungal:
- clotrimazole
- miconazole
How is Pityriasis Versicolor treated?
Topical or systemic antifungal
- topical ketoconazole
- systemic itraconazole
What are examples of skin infestations?
- scabies
- lice
How is scabies spread?
skin-to-skin contact
How does Scabies present?
- itching (severe at night)
- rash on trunk and limbs
- burrows appear on skin
How is scabies treated?
- benzyl benzoate
- permethrin
- malathion
How are lice transmitted?
close contact with an infected individual or shared items
How are lice treated?
- personal and clothing hygiene
- chemical insecticides (permethrin)
What are examples of inflammatory skin disease?
- eczema
- occupational dermatitis
- psoriasis
What are the 2 types of eczema?
- atopic
- contact
What is eczema?
Inflammation of the skin
- becomes itchy, dry, flakey
- occasionally weeps
What is the commonest form of eczema?
atopic eczema
- develops in childhood
- usually improves with age
What are triggers for eczema?
- stress
- mensuration
- illness
- changes in weather
How is eczema managed?
- cotton clothing
- emollients
- soap substitutes
- corticosteroids
What is contact dermatitis?
reaction to an environmental agent resulting in a rash with an intense itch
How is contact dermatitis treated?
Remove source
- topical steroids can help
What is psoriasis?
Dysregulated epidermal proliferation
- skin surface builds up & thickens
How is psoriasis treated?
- emollients
- topical steroids
- tar
- dithranol
- vitamin A derivatives
- PUVA (activated by UV light)
What systemic drugs can be used to treat psoriasis?
- methotrexate
- cyclosporin
- aitretin
- infliximab
What are examples of immunological skin diseases?
- blistering conditions (pemphigoid)
- lichen planus
- connective tissue diseases (scleroderma, raynauds)
How do immunological skin diseases occur?
- auto-antibody attack on skin components causing loss of cell to cell adhesion
- split forms in skin (fills with inflammatory exudate and forms vesicle/blister)
What are examples of vesiculobullous diseases?
- pemphigoid
- pemphigus
- epidermolgysis bullosa
- linear IgA disease
- dermatitis herpetiformis
What is Pemphigoid?
presents as thick walled blisters
How is pemphigoid managed?
Immunosuppressants
- steroids
- ‘steroid sparing’ drugs
What is pemphigus?
Fatal disease without treatment
- oral lesions usually seen before skin
- intra-epithelial blister
What problems are associated with Epidermolysis Bullosa?
- infection
- fluid loss
- scarring
