Skin structure and function 4 Flashcards
What are the 6 main functions of the skin ?
- Barrier function
- Metabolism & detoxification
- Thermoregulation
- Immune defence
- Communication
- Sensory functions
Name and briefly describe what is going on here
Acute skin failure caused by toxic epidermal necroylsis
Toxic epidermal necrolysis = a potentially life-threatening dermatologic disorder characterized by widespread erythema, necrosis, and bullous detachment of the epidermis and mucous membranes, resulting in exfoliation and possible sepsis and/or death.
Acute skin failure = a state of total dysfunction of the skin resulting from different dermatological conditions. It constitutes a dermatological emergency and requires a multi-disciplinary, intensive care approach.
Name and briefly describe the condition shown
Erythroderma - is the term used to describe intense and usually widespread reddening of the skin due to inflammatory skin disease. It often precedes or is associated with exfoliation (skin peeling off in scales or layers), when it may also be known as exfoliative dermatitis (ED).
Describe the barrier function of skin
It is a two way barrier: epidermis which prevents against physical, chemical damage and damage from pathogens.
- Physcial damage e.g. Friction/ mechanical trauma, UV radiation
- Chemical damage e.g. from irritants, allergens, toxins
- Damage from pathogens e.g. Bacteria, viruses, fungi
Name and briefly describe the condition shown
Steroid-sulphatase deficiency X-linked ichthyosis - a skin condition caused by the hereditary deficiency of the steroid sulfatase (STS) enzyme
What could be the condition shown below ?
Cumulative irritant hand dermatitis
What is shown in the pic ?
Ulcer following a compound fracture
Appreciate the function of melanin protecting the DNA in cells nuclei
Describe the functions of skin in metabolism and detoxification
Skin is metabolically active:
- –Vitamin D metabolism
- –Thyroid hormone metabolism (T4 ==> T3 conversion only 20% occurs in the thyroid gland, the other 80% occurs in tissues peripheral to the thyroid such as the skin).
- –Defence against chemicals, drugs, pollutants & sunlight
Explain vitamin D metabolism in realtion to the skin
Cholecalciferol (7-dehydrocholesterol) is acted on by UV radiation which converts it to ====> Vit D3
Vitamin D3 stored as hydroxycholecalciferol in liver
Converted to 1,25-dihydroxycholecaliferol in kidney
Describe the skins role in thermoregulation
•Protects against being too hot or too cold has Warm/cold-sensitive thermoreceptors which if you are to hot or cold results in:
- *Behavioural changes
- Control sweating/shivering/blood supply
Describe the skins role in immune defence
•Important in:
- *Protection against infection
- *Sunlight responses
- *Allergic reactions
- eg. to chemicals/drugs
•Langerhans’ & T cells important
Name and briefly describe the condition shown - hint the patient is finding the rash itchy which is worse at night
Scabies - a contagious skin condition caused by tiny mites that burrow into the skin. Main symptom is itchiness which is worse at night and also redness where the mites may have burrowed
What is shown in the pic ?
Granulomas
What is Eczema herpeticum?
Eczema herpeticum is a disseminated viral infection characterised by fever and clusters of itchy blisters or punched-out erosions. It is most often seen as a complication of atopic dermatitis/eczema.
What is Chronic discoid lupus erythematosus?
Discoid lupus erythematosus (DLE) is a chronic skin condition of sores with inflammation and scarring favoring the face, ears, and scalp and at times on other body areas. These lesions develop as a red, inflamed patch with a scaling and crusty appearance.
Describe the sensory functions of the skin
- Touch, pressure, vibration
- Pain & itch
- Heat & cold
- Nerve endings and receptors in skin
