week 3 Flashcards
primary vs secondary lesion
Primary lesion: initial lesion that has not been altered by trauma or manipulation, and has not regressed
Secondary lesion: develops as the disease evolves or as the patient damages the lesion i.e. rubbing, scratching, infections.
primary lesions > 1 cm
bulla
nodule
patch
plaque
Bulla: A circumscribed, elevated lesion that
measures ≥ 1 cm and contains serous or hemorrhagic fluid (i.e., a large blister)
Nodule: A palpable, solid, round ellipsoidal lesion measuring ≥ 1 cm; it differs from a plaque in that it is more substantive in its vertical dimension compared with its breadth.
Patch: A circumscribed, nonpalpable discolouration of the skin that measures ≥ 1 cm.
Plaque: A palpable, solid lesion that measures ≥ 1 cm.
primary lesions < 1cm
macule
papule
petechiae
vesicle
Macule: A circumscribed, nonpalpable discolouration of the skin that measures <1 cm in diameter.
Papule: An elevated, solid lesion that measures < 1 cm.
Petechiae: Nonblanching reddish macules representing extravascular deposits of blood, measuring ≤ 0.3 cm (less than the size of a pencil eraser).
Vesicle: A circumscribed, elevated lesion that measures <1 cm and contains serous or hemorrhagic fluid (i.e., a small blister).
wheal
pustule
purpura
Wheal: A round or annular (ring-like), edematous papule or plaque that is characteristically evanescent, disappearing within hours; may be surrounded by a flare or erythema (i.e., a hive)
Pustule: A lesion that contains pus; may be follicular (centered around a hair follicle) or nonfollicular.
Purpura: Nonblanching reddish macules or papules representing extravascular deposits of blood, measuring > 0.3 cm.
secondary lesions
atrophy
crust
erosion
lichenification
scale
scar
ulcer
Atrophy
A depression in the skin resulting from thinning of the epidermis, dermis and/or subcutaneous fat.
Crust
A collection of dried blood, serum, and/or cellular debris.
Erosion
A focal loss of epidermis does not penetrate below the dermal-epidermal junction and, therefore, can heal without scarring.
Lichenification
Thickening of the epidermis resulting from repeated rubbing, appearing as accentuation of the skin markings.
Scale
Excess dead epidermal cells; scale may be fine, silvery, greasy, desquamative, or adherent.
Scar
Abnormal formation of connective tissue, implying dermal damage.
Ulcer
A focal loss of full-thickness epidermis and partial to full-thickness dermis, which often heals with scarring
global reaction patterns
Papulosquamous eruptions (Papules and plaques with scale)
Folliculopapular eruptions (perifollicular papules)
Dermal reaction patterns
Purpura and petechiae
Nonpalpable purpura
Blistering disorders (vesicles, pustules and bullae)
history in derm
When? Onset
* Where? Site of onset
* Does it itch or hurt? Symptoms
* How has it spread (pattern of spread)? Evolution
* How have individual lesions changed? Evolution
* Provocative factors? Heat, cold, sun, exercise, travel history, drugs, pregnancy, seasonal changes
* Exposure(s) at the site? Changes to routines (laundry detergent, cosmetics, cleaning products etc.?
* Previous treatment(s) and response to Treatment: Topical and systemic
* Constitutional symptoms? Headaches, fever, chills, weakness, malaise arthralgias, etc.
* More chronic ones – weight loss, weakness, malaise
physical exam for derm
General shape: round, oval, polygonal, polycyclic, annular (ring-shaped), iris,
serpiginous (snakelike), umbilicated.
* Size
* Colour
* Margination
* Well defined
* Ill defined
* Palpation
* Consistency (soft, firm, hard, fluctuant, board-like)
* Deviation in temperature (hot, cold)
* Mobility
* Tenderness?
* Estimate the depth of the lesion (i.e. dermal or subcutaneous)
Number: Single or multiple lesions
Arrangement: Multiple lesions may be:
* Grouped: herpetiform, arciform, annular, reticulated (net-shaped), linear,
serpiginous
* Disseminated: scattered discrete lesions Confluence: Yes or no
Distribution:
* Isolated?
* Localized vs. regional vs. generalized
* Pattern: symmetric, exposed areas, sites of pressure, intertriginous area, follicular localization, random, following dermatomes or Blashko lines
ABCDEs for melanoma and dysplastic nevi (nevus)
asymmetry
irregular borders
variegated colour
diameter (>6mm)
evolution/ enlargement (change over time)
oblique vs subdued lighting
Oblique lighting: Used to view degrees of elevation or depression in a lesion. Done in a darkened room.
- Subdued lighting: Used to enhance the contrast between circumscribed hypopigmented or hyperpigmented lesions and normal skin.
wood lamp in derm
to see different in colour and melanin pigments
diascopy vs dermascopy
Diascopy
* Firmly pressing a microscopic slide or glass spatula over a skin lesion.
* The examiner determined whether the red colour of a macule of papule is due to capillary dilatation (erythema) or due to extravasation of blood (purpura) that does not blanch.
Dermoscopy (also called epiluminescence microscopy)
* A hand lens with built-in lighting and a magnification of 10x to 30x is called a dermatoscope and allows for inspection of deeper layers of the epidermis and beyond. Helpful to distinguish between a benign and malignant lesion.
* These tools are typically used by dermatologists and not necessary in a naturopathic medical practice
patch testing vs prick testing
patch = allergic contact
prick= type 1 allergies; wheal appears
Patch testing
* Used to confirm a diagnosis of allergic contact sensitization and identify the agent that caused the allergic reaction.
* Substances to be tested are applied to the skin in shallow cups (Finn chambers), taped onto the skin and left in place for 24 – 48 hours. Contact hypersensitivity will show as a papular vesicular reaction that will develop within 48 to 72 hours when the test is read.
Prick testing
* Used to determine type I allergies
* A drop of a solution containing a small amount of the allergen is placed on
the skin and the skin is pierced through this drop with a needle.
* A positive result would be a wheal appearing within 20 minutes.
* Caution – the patient needs to be under constant supervision due to possibility of anaphylaxis.
skin scraping
what chemical is used?
- Dermatophyte/KOH Collection
- Microscopic examination for mycelia should be made of the roofs of vesicles or of scales or in the hair in dermatophytosis.
- The tissue is cleared with 10 to 30% KOH and warmed gently. Hyphae and spores can then be viewed.
- Microbiology (Culture and Sensitivity) and Specimen Handling Biopsy
biopsy
Biopsy
* Different tools can be used for different types of lesions
* Punch biopsy:
* Useful in the work-up of cutaneous neoplasms, pigmented lesions, inflammatory lesions and chronic skin disorders.
* 3 to 4 mm punch, a small tubular knife cuts through the epidermis, dermis and subcutaneous tissue by rotating the tool.
* Excisional biopsy (wide local excision)
* Surgical removal of a tumour and some normal tissue around it.
epidemiology of sebhorreic dermatitis
-males, babies or 40+
-hyperandrogenism
-stress
-cold weather
-immunosuppression
-zinc deficient
what is sebhorreic dermatitis and its causes
-sebaceous gland inflammation
-androgen hormones, Malassezia yeast infection, altered immunologic response
atopic dermatitis pathophysiology
Ig_?
-Allergic, inflammatory
-Epidermal barrier dysfunction
-Elevated IgE
contact dermatitis pathophysiology
2 types;
type __ hypersensitive?
-erythema + pruritis from exogenous agent
1. irritant CD: chemical or physical abrasion (i.e. creams, alcohol, friction, temp)
2. allergic CD : delayed immunologic (type IV hypersensitivity)
Dyshidrosis (acute palmoplantar eczema) pathophysiology
nonspecific immunologic reaction
-delayed hypersensitivity rxn
-acute spongiotic formation in epidermis of palmoplantar surfaces
-overexpress aquaporin (water and glycerol transport to epidermis)
-filaggrin mutations
