The skin is formed of the epidermis and the dermis.
What are the 4 parts of the epidermis?
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Basal cell layer
What can we found in the skin dermis?
Blood vessels Nerves Inflammatory cells Hair follicles Sebaceous glands Collagen fibres Adipose tissue Sweat glands
Why does the skin have a complex vascualr network?
Formed of superficial and deeper plexus.
Interconnecting blood vessels between the layers.
Superficial blood vessels cool the skin and deeper layers retain heat.
Name the main functions of the skin
- Protection from the environment
- Thermoregulation : shunting blood to surface to lose heat or deeper to retain heat. Sweat glands and hair follicles.
- Neuroreceptors : found in skin to allow our perception to the environment
- Immunological role : langerhan cells found for antigen processing
- Synthesis of vitamin D needed for calcium absorption
- Cosmetic - impacts someones well being if there is damage to the patients skin
What information do we need when taking a skin history?
- History of presenting complaint
- Current / past treatment
- Medical history
- Family history
- Drug history
- Allergies
When the skin scales, what layer of the skin is scaling?
Stratum corneum
What is the difference between lichenification and excoriation?
Lichenification : thickening that occurs from scratching
Excoriation : cut and splits in skin that can lead to secondary infection
What investigations can we do for skin?
- Swabs of the skin or skin scrapings
- Skin biopsy
- Patch tests for allergy
- Photo tests (UV light to see if patient has a UV sensitivity)
- Full blood count
- Biochemistry for liver&kidney function, diabetes, CRP levels
- Immunological tests (looking for autoantigens such as ANA, dsANA, ro and la)
- Virology (herpes simplex serology)
What is eczema and how many people in the population does it affect?
It is an itchy inflammatory condition associated with dryness and redness of the skin.
20% of people
Name the 6 types of eczema
- Atopic (dry, itchy and cracked skin)
- Flexural eczema (found on flexural sites)
- Varicose eczema (dryness on lower leg due to varicose veins)
- Seborrhoea eczema (mainly affects scalp causing scaly patches, red skin and dandruff)
- Discoid eczema (circular or ovular patches of eczema)
- Lichen simplex : area of thickened dry scaly skin
What are the two types of dermatitis?
1) Irritant contact dermatitis
2) Allergic contact dermatitis : type 4 hypersensitivity
What ways do we manage eczema?
- Avoid soap and shower gel
- Use moisturisers and emollients
- Topical steroids (hydrocortisone)
- Oral steroids
- Oral antibiotics when infected
- Antihistamines
- Wet wraps
What is the dental relevance of eczema?
- Steroids being taken - increases risk of infection
- Painful to brush teeth if eczema is on hands
- Eczema can affect the lips
What is psoriasis and what are the types?
Hyperproliferation of the skin leading to symmetrical well defined plaques with a thick silvery scale.
Types:
- Psoriasis vulgaris - most common, chronic plaque psoriasis with silvery scale
- Guttae - tear drops following sore throat after streptococcal infection
- Erythrodermic - widespread red spread skin
- Pustular
How is psoriasis treated?
- Avoid soaps
- Use moisturisers and emollients
- Vitamin D analogues (supplement as skin cannot produce any)
- Topical steroids
- Dithranol (cream applied to plaques)
- UVB (to kill outer skin cells to get rid of plaques)
- Immunosupressants
What is lichen planus and what does it appear like on skin?
Autoimmune disease of unknown aetiology.
Leads to flat topped violet papules on skin which may result in scarring.
How do we treat lichen planus?
Topical : moisturise with emollients, topical steroids
Systemic : steroids (prednisolone), immunosuppressants (methotrexate, azithroprine)
What are the main causes of itch?
- Dry skin
- Dietary (iron deficiency anaemia)
- Endocrine (thyroid disorders, diabetes)
- Inflammatory (eczema, urticaria)
- Autoimmune (lichen planus, dermatitis herpetiformis)
- Infective (chicken pox)
- Infestations
- Parasitic
- Underlying malignancy
What are the 2 common viral skin infections?
Chicken pox (varicella zoster virus) - lives in dorsal root ganglia and then can remerge as shingles
Herpes Simplex
What are the 3 main bacterial infections?
1) Impetigo (acute skin infection)
2) Cellulitis (staph and strep leading to spreading skin infection)
3) Paronychia
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Cardiovascular Disease20
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Oral facial and bone neoplasms10
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Infective endocarditis18
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Dermatology20
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Respiratory Disease0
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Haematology 135
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Haematology 228
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Rheumatology43
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Neurology 137
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Neurology 20
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Allergy to dental materials0
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Medically compromised patient13
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GI 144
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GI 229
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Liver Disease19
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Psycho-social33
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Kidney disease20
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Anesthetic assessment21
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Chemotherapy and immunosuppression31
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Swellings of head and neck and ENT problems22
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Endocrinology40
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Oral Manifestations of Disease17
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ASA Classification14
