Flashcards in Skin Deck (57)
Loading flashcards...
1
What is the layers of the skin (biggest organ of the body)
Epidermis
Dermis
Hypodermis = subcutaneous tissue which anchos skin to fascia (useful in insulation)
Skin appendages = derived from skin cells
- Hair
- Nails
- Sebaceous glands
- Sweat glands
2
What is the epidermis made up of and what pathology can affect
Striatum cornea (thick top layer made up of keratin)
- Thickest in palms and soles
- Thin at eyelids
Keratonocytes - produce keratin
Melanocytes - produce melanin
Lagerhan's - immune (process antigen and migrate to LN)
Average turnover = 30 days
Pathology
- Change in turnover e.g. psoriasis
- Change in surface or loss of epidermis e.g. scales / ulcer
- Change in pigmentation
3
What is the dermis made up of
Collagen = mainly
Fibroblasts synthesis elastin
Dendiritc cells for immune
Nerves + blood vessels
Adrenal structures - hair / glands / sensory
Pathology
- Change in contour / loss of dermis
- Disorder of skin appendages - hair / acne (Sebaceous gland)
- Change lymphatics / blood vessel - erythema, urticaria, purpura
4
What are nails made up of
Nail plate (hard keratin) which arises from nail matrix at posterior nail fold and rests on nail bed
Nail bed contains capillaries which give colour
5
What is the stages of the hair cycle and types of hair
Lanugo - fine long hair in fetus
Vellus - fine short hair on all areas
Terminal - coarse long hair on scalp, eyebrows, eyelash and pubic
Hair shaft - keratinised tube
Hair bulb - actively dividing cells and melanocyte which gives pigment
Anagen = active growing
Catagen = growth stops + follicle shrinks
Telogen = resting phase
6
What are the functions of the skin
Thermoregulation - insulation / sweat / blood flow
Immune system - innate and adaptive
Barrier
Sensation
Synthesis of Vitamin D
Personal communication
7
What causes skin disease
Photosensitivity - often medication
Temperature - frost bite / necrosis / cold urticaria
Trauma - dermatitis artefacts
Genetics - eczema / psoriasis / acne / neurofibroma
Autoimmune - bullous pemphigoid
Infection
Systemic
8
What is a macule
Small flat circumscribed area <5mm of altered colour
9
What is a patch
Larger flat area of altered colour >5mm
10
What is a papule
Small raised area <0.5cm
11
What is a plaque
Large raised area >0.5cm
12
What is a vesicle
Small fluid filled lesion <0.5cm
13
What is a bullae
Large fluid filled
14
What is a pustule
Small pus
15
What is an abscess
Large pus in dermis or subcutaneous tissue
16
What is wheal
Transient raised lesion due to localised oedema
17
What is an erosion
Superficial loss of epidermis
Heals without scarring
18
What is an ulcer
Loss of epidermis and denims
Heals with scarring
19
Why can skin regenerate
Has stem cells
20
What causes purpura in children
Thrombocyotpenia
Meningococcal septicaemia - non-palpable
ALL
Congenital bleeding disorder
ITP
HSP - tend to be palpable
NAI
21
What should you do to all children with new onset purpuric rash
Always admit to exclude life threatening
Ax prior to transfer to hospital as may be due to menigococcal septicaemia
Clotting screen and platelet to exclude coagulation disorder
22
What causes purpura in adults
Vasculitis
Bone marrow failure
ITP
Drugs
Nutrition
23
What can distribution of skin disease be
Localised
Generalised
Symmetrical
24
How can you investigate skin disease
Charcoal swab - bacterial and fungal
Viral swab - vesicular eruption
Skin scraping
Nail scraping
Dermoscopy
25
What do you send swab for
MC+S if charcoal
PCR if viral
Biopsy
26
Do you swab in cellulitis
No as will have pyrexia so need blood culture
27
What do you do if fungal suspect
Skin scraping
Nail clipping
Hair sample
Fungal culture
28
What is important in HPC of skin problem
Duration
Initial appearance and evolution
Symptoms - itch / pain
Aggravating and relieving factors
Previous and current Rx
Recent contact / stress / travel
Hx sunburn or sunbeds
Skin type
29
What else is important
PMH - atopy / skin cancer
FH - skin disease
SH - occupation / do skin lesions improve
DH
QOL
30
