Dermatology Flashcards
(45 cards)
What are the 3 layers of the epidermis? (outer layer to inner)
Stratum corneum
Stratum granulosum
Basal Layer
What are the functions of the skin?
Protection from the environment (chemical, thermal, physical, UV) Thermoregulation Neuroreceptor (external stimuli) Antigen processing (Langerhan's cells) Synthesis of vitamin D Cosmetic
What history taking would you take in a patient with a skin disorder? (8)
Age,sex, occupation History of presenting complaint Relevant systems review Current/past treatment Past MH family history Drug history Allergies
What 3 things do you note when examining a skin condition?
- SITE: is it localised/generalised, distribution skin and/or mucosal membranes
- MORPHOLOGY: mono/polymorphic, blister/erosion/scarring
- BACKGROUND SKIN: normal/erythema (redness)
What is a macule?
<1cm.
It is a flat, circumscribed lesion on the skin which are not palpable.
They may be pigmented, red or non-pigmented.
What is a patch?
> 1cm flat, circumscribed lesion on skin that is not palpable.
They may be pigmented, red or non-pigmented.
What is a plaque (in terms of dermatology)?
> 1cm in diameter - Slightly raised, flat topped lesion
What is a papule?
Circumscribed
Palpable
Elevated
<1cm
May be itchy
What is a nodule?
Palpable elevation >1cm
What colour must you look out for in lesions which may indicate that a rapid referral is required?
If a lesion is brown/black - or if a lesion that is irregular in colour has some brown/black in it. May be malignant or on it’s way to becoming malignant
What is scale?
Peeling of stratum corneum/superficial epidermis.
Due to dryness of skin, lack of skin barrier
Will be itchy as skin is dehydrated
What do you call a small blister?
Vesicle (<0.5cm in diameter)
What is it called when skin becomes thick and leathery (e.g. from scratching)?
Lichenification
What do you call it when there is “a shallow breach in the surface from scratching often with a hemorrhagic crust?”
Excoriation
What do you call a blister that is more than 0.5cm in diameter?
Bulla
What would you call a full thickness loss of epidermis?
Ulcer
What is a scar?
It is a permanent change in skin surface/texture
What tests could you order to help diagnose a condition?
- Skin swabs/scrapings - bacteriology, virology, mycology
- Skin biopsy - histology, culture, immunofluorescence
- Patch tests - undertaken if a contact allergy is suspected
- Photo-tests - investigate a possible sensitivity to UV
What skin condition is a pruritic inflammatory condition associated with dryness and erythema of skin and scratching this results in excoriation and lichenification?
Eczema
Name 3 sub-types of eczema
Atopic/flexural
Varicose (lower legs, venous incompetence)
Seborrhoeic (centre of face usually)
Discoid (coin-shaped lesions)
Lichen simplex (thickened, dry scaly skin)
What 2 environmental factors mat also cause dermatitis?
IRRITANT contact: e.g over hand washing
ALLERGIC contact: sites that had direct contact with allergen.
In what type of patients would you typically find allergic contact dermatitis?
Patients with type 4 (delayed) hypersensitivity to a specific allergen
What microorganisms may secondarily infect eczema?
S. Aureus - impetiginised eczema: yellow crust and weeping
Herpes simplex - eczema herpeticum: monomorphic lesions
What would you advise patients with eczema to avoid?
Soap, shower gel and contact with irritants (e.g. domestic cleaning agents)
