W8L6: Introduction to Dermatology and Skin Infections Flashcards
What are the key questions on history for someone with a rash (besides usual SQSTCARA)?
When/ in what context did it begin?
Where did it begin?
How has it evolved?-> Where did it start, where has it gone and how else has it changed?
Ass F: Pain (red flag), itch, bleeding
Ever happened before?
Have you come into contact with any new substances?
Have you commenced any new medications including OTC, herbs, immunisations.
Has anyone else around you had a similar rash?
What are the key other symptoms that may acompany a rash that you need to ask about?
– Shortnessof breath – Tongueswelling – Joint pain – Fever, sweats – New lumps or bumps
What are you worried about with presentation of a PAINFUL skin lesion?
SSC
What is erythema due to?
Vasodilation
What is the significance of non-blanching erythema?
RBs have extravasated into the skin (pushing onto skin should constrict the vessels and blanch the area)
What are the things you are worried about if erythema cover more than 90% of the body?
Shock, heat loss, protein and water loss (similar to a burn)
What is scale due to?
Abnormal accumulation of keratin in the epidermis.
Can be due to overproduction or not shedding enough.
What causes psoriasis?
Overproduction of keratin
What is the presentation of asteatotic eczema and what is this due to?
Scaly skin–> retain top layers of epidermis inappropriately, and they don’t stick together properly.
What is a macule? + 2egs
flat lesion of skin that has hyper or hypo-pigmentation. Impalpable.
eg: freckles, vitiligo
What is a papule?+2 egs
Elevated (palpable
lesion), <5mm
eg: keratosis pilaris, pimple without a heard (ie prior to filling with neutrophils)
What is a nodule?
Elevated (palpable
lesion),>5mm“Lump”
What is the presentation of a basal cell carcinoma?
“pearly” coloured, vascular, ulcerated
Which skin cancers can become hyperkeratotic?
SCC
What is a cyst?
Cystisnodulethathas fluid within - fluctuant
What height of a raised nodule indicate?
More height= invaded lower down into dermis
What is a plaque? +1eg
Plaque – Circumscribed, elevated area of skin – Broadness is greater than thickness eg: Psoriasis
What is a wheal? What does it indicate?
– Area of localised oedema and erythema of skin. Indicates dermal change (rather than epidermal)
What is a vesicle?
+2egs
Fluid-filled blister of the epidermis
eg: Herpes zoster (shingles), herpes simplex (cold sore)
What is a bullae
Blister >5cm that extends deeper than the epidermis
eg: bullous pemphigoid, an autoimmune condition that causes separation of the dermis and epidermis.
What is a pustule?
– A vesicle or bulla
containing pus
– Pus may be sterile
What is an example of infective pustules and an example of sterile pustules?
Infective folliculitis (Staph. Aureus)
Pustular psoriasis (Sterile pustules)
What is an erosion? 1eg
– A superficial loss of
epidermis
– Does not scar
eg: impetigo (S. aureus)
What is an ulcer? 2egs
– An area of tissue loss
through dermis
– Forms scars
eg: from pyoderma gangrenosum, or caused by advanced breast cancer