Dermatology Flashcards
what are the layers of the skin
epidermis (this is split into the stratum corneum, stratum granulosum, stratum spinosum and stratum basalt)
dermis
subcutaneous tissue
where is the epidermis derived from
ectoderm
what are the role of langerhans cells and where do they reside
the reside in the basal layers of the skin
specialise in antigen presentation - acquire antigens in peripheral tissues and transport them to the regional lymph nodes, present them to naive T cells and initiate the adaptive immune response
these activated T cells initiate the cytokine release cascade
have major roles in:
- antimicrobial immunity
- skin immunosurveillance
- induction hypersensitivity and pathogenesis of chronic inflammatory diseases of the skin
what are the effects of UV on the skin
- direct cellular damage
- alterations in immunologic function
- direct effects include photoaging, DNA damage and carcinogenesis
what are the effects of UV damage on the p53 tumour suppressor gene
these are mutated and it is implicated in the development of melanoma and non melanoma skin cancers
what tries to protect the skin from UV damage
keratinocytes
melanocytes
what does chronic exposure to UV cause in humans
loss of skin elasticity, fragility and abnormal pigmentation and haemorrhage of blood vessels
wrinkles and premature ageing
draw me the vitamin D diagram
what are the impacts of vitamin D deficiency
- increased risk of common cancers
- autoimmune diseases
- infectious diseases
- cardiovascular disease
Merkel cells
these are at the BASE of the dermis and respond to sustained gentle and localised pressure, assess shape and edge of objects
messier corpuscles
situated immediately below the dermis and are particularly well represented on the palmar surfaces of the fingers and the lipssensitive to light tough
Ruffinis corpuscles
situated in the dermis and are receptors sensitive to deep pressure and stretching
pacinian corpuscles
mechanoreceptors present in the deep dermis sensitive to deep touch, rapid deformation of the skin surface and around joints for position and proprioception
pacinian corpuscles
mechanoreceptors present in the deep dermis sensitive to deep touch, rapid deformation of the skin surface and around joints for position and proprioception
free nerve endings
pain and tempterture
what is the aetiology of acne
there is keratin and sebum blockage of the sebaceous gland
androgenic increased sebum production and viscosity and this leads to proprioni bacterium inflammation
What three features do you need to diagnose acne
papules
pustules
comedones (white and black heads)
acne fulminans
this is a severe condition with an acute onset presenting with fever, bone pain etc.
what are the treatment options for ACNE
reduce plugging - topical retinoid or topical benzoyl peroxide
reduce bacteria - topical antibiotics - oral antibiotics
reduce sebum production - hormones such as anti-androgens
side effects to some topical agents
irritant, burning, peeling and bleaching
Side effects to oral antibiotics
gastro upset
what causes atopic eczema
high Ig-E immunoglobulin antibody levels
how is atopic eczema managed
emmollients
topical steroids
manages
antihistamines
antibiotics and antiivirals
education for child and patient
avoidance of exacerbating factors
what are the two types of contact dermatitis - exogenous agents
irritant - direct noxious effect of the skin barrier
allergic - type IV hypersensitivity reaction
what are the two types of contact dermatitis - exogenous agents
irritant - direct noxious effect of the skin barrier
allergic - type IV hypersensitivity reaction
presentation of seborrhoea dermatitis
chronic scaly inflammatory condition
looks like dandruff
caused by an overgrowth of pittosporum oval yeast
can be severe in HIV
what is the treatment for seborrhoea dermatitis
scalp - anti yeast shampoo
face - anti-microbial, mild steroid and a simple moisturisers
often improves with UV/Sunlight
venous dermatitis
underlying venous disease
affects the lower legs
incompetence of the Depp perforating veins that results increased hydrostatic pressure
management of venous dermatitis
emollients
mild/moderate topical steroid
compression banding/stockings
consider early venous surgical intervention
what is the definition of psoriasis
chronic relapsing and remitting scaling skin disease which may appear at any age and affect any part of the skin
it is caused by a t-cell mediated autoimmune disease
what are some of the scoring systems used in psoriasis
DLQI - disease life quality index (patient)
PASI - Psoriasis area severity index (clinicians)
PEST - psoriasis epidemiology screening tool (5 questions survey to deem severity of the disease)
what are some features of a basal cell carcinoma
- shiny
- lightening blood vessels (telangiectasia)
- often ulcerated centrally
what is the best treatment for a basal cell carcinoma
surgical excision with a 3-4mm margin
- curettage and cautery
- cryotherapy
where does squamous cell carcinomas originate from
keratinocytes
