Dermatology Flashcards
Scale
type of surface change resulting from excess stratum corneum (superficial layer of skin) that accumulates flakes or plates
Crust
hardened layer that results when serum, blood or exudate dries on skin surface
Pathophysiology of acne
Androgens in the circulation
Bacteria in the hair follicle
Follicular plugging
Sebum secretion
Rosacea
Rosacea is a common skin condition with characteristic symptoms and signs, including symmetric flushing, stinging sensation, inflammatory lesions (papules and pustules), and telangiectasias on the face.
Acrochordon
small, soft, common, benign, usually pedunculated neoplasm
AK definition
Actinic keratoses (AKs) are premalignant inflammatory skin lesions with the potential to transform into squamous cell carcinoma (SCC).
AK treatment
Liquid nitrogen (Cryosurgery) – freezing the affected tissue
5-Flurouracil (5-FU)
Aldara - has been approved in Canada and the US.
View the A-Detail™ on Aldara™.
Solaraze - Currently approved in the US only
Curettage / electro-desiccation
Excision – surgically removing the affected tissue (rare)
Photodynamic therapy
Lentigines description
A brown, sharply circumscribed macule resembling a freckle
AK description
a premalignant condition of thick, scaly, or crusty patches of skin
Ex: Well-circumscribed, 2cm, erythematous nodule with central ulceration and crust. The lesion is firm with palpation.
BCC
- malignancy of the basal cells of the epidermis
- most common human malignancy
BCC RF
- major risk factor is cumulative sun exposure, eighty-five percent occur on the head and neck, with the nose being the most common site
- Usually in pt 40-80
BCC description (nodular)
translucent, waxy papule with a rolled, pearly border, telangiectasia, and often central ulceration.
Recurrence rates for surgical options for BCC
curettage and desiccation 10%
cryotherapy 10%
excision 2 - 5%
Mohs <1%
BCC superficial description
Superficial BCC occurs as irregularly shaped, slow-growing, circumscribed, round-to-oval, red, scaling plaque
Indications for TBSE
Personal history of skin cancer
Inc. Risk for melanoma - 2 first degree relatives, over 100 nevi
New rash on body
New patient with undiagnosed skin condition
F/u in patients with extensive skin conditions (ie psoriasis)
Frequently missed spots to look for skin problems
Medial canthi
Alar creases
Conchal bowl
Postauricular fold
Plaques
proliferation of cells in superficial dermis or epidermis
Acral distribution
distal aspects of the head (ears, nose) and the extremeties
Intertriginous distribution
in skin folds (axilla, crural, gluteal)
distribution pattern that follows sun exposed skin
Photodistributed
Random lesions in many body locations
scattered
superficial loss of the dermis
erosion
Erosion that involves the dermis
ulcer
Epidermis consists of
The epidermis is the topmost layer, and consists primarily of keratinocytes.
Dermis consists of
The dermis lies below the epidermis, and consists primarily of fibroblasts, collagen, and elastic fibers.
Beneath the dermis…
Subcutis
4 layers of epidermis
Stratum corneum Stratum granulosum (granular cell layer) Stratum spinosum (spiny layer) Stratum basale (basal cell layer)
Think of stratum corneum as a wall of bricks and mortar
Bricks: flattened keratinocytes filled with keratin and filaggrin
Mortar: lipid mixture, which surrounds the keratinocytes and provides the water barrier (lipids produced by granular layer)
Filagrin protein
retains water in the kerationocytes
- mutations cause atopic dermatitis, other
diseases of the skin
Psoriasis pathophysiology
rapid epidermal turnover (not enough time for differentiation at each level)
3 types of cells that make up the epidermis
Keratinocytes Melanocytes Langerhans cells
Melanocytes function
pigment producing cells, transfer their pigment to the keratinocytes in the basal cell layer
Langerhans cells function
provide recognition, uptake procession and presentation of antigens to T cells for induction of delayed type hypersensitivity
Dermis layers
Papillary and reticular
Dermis function
support structure
contains blood and lymph vessels + nerves that supply the skin
contains sweat glands and hair follicles
Cells of the dermis
fibroblasts and mast cells
fibroblasts function
important for wound healing
mast cells function
responsible for immediate type hypersensitivity reactions in the skin
Sebaceous hyperplasia versus BCC
Yellow color, umbilication, and multiple similar papules help identify sebaceous hyperplasia
• BCC tends to be solitary and more friable (bleeds, scabs) – also more pearly translucent, often with telangiectasia
Epidermal inclusion cyst
mobile subcutaneous nodule, often with an overlying punctum
- arise from hair follicles, not oil glands
Debris (dead skin cells, oil, etc.) collects within a sack
Actinic keratosis differential
Actinic keratosis Basal cell carcinoma Melanoma Seborrheic keratosis Squamous cell carcinoma Verruca vulgaris
verruca vulgaris
Hyperkeratotic, exophytic (growing outward), dome- shaped papules or nodules
Punctateblackdots representing thrombosed capillaries
type of wart morphologies
Verruca vulgaris: common warts
Verrucae planae: flat warts
Palmoplantar warts
Condylomata acuminata: external genital warts
Side effect of cryotherapy
post inflammatory hyperpigmentation
flat warts first line treatment
Cryotherapy
Salicylic acid (caution using on face)
Topical tretinoin
external genital warts description
broad-based papules or large confluent plaques
HPV 11, 6
molluscum contagiosum
smooth, dome-shaped papules with central umbilication
Genital wart treatment
Cryotherapy
Imiquimod
Salicylic acid
Classification of acne
Comedonal: open and closed comedones Inflammatory: papules and pustules Nodulocystic: nodules and cysts
benzoyl peroxide MOA
antibacterial and comedolytic
topical antibiotics
reduces P acnes and reduces inflammatory acne
Erythromycin 2% (solution, gel) Clindamycin 1% (lotion, solution, gel, foam)
topical retinoids SE
dryness, pruritis, erythema, scaling, photosensitivity
benzoyl peroxide SE
bleaching of hair, clothes, etc
Topical agents for acne time of action
2-3 months
Oral antibiotics for acne, uses
tetracycline, doxycycline, minocycline
Used for moderate to severe acne
Tetracycline side effects
Are contraindicated in pregnancy and in children <8 years old
May cause GI upset (epigastric burning, nausea, vomiting and diarrhea can occur)
Can cause photosensitivity (patients may burn easier, which can be easily managed with better sun protection). Recommend sun block with UVA coverage for all acne patients on tetracyclines
tetracyclines DO NOT interfere with OCP
Takes 2-3 months for improvement
Minocycline side effects
GI upset, vertigo, hyperpigmentation
Acutane SE
xerosis cheilitis elevated LFTs hypertriglyceridemia mood changes pseudotumor cerebri
seborrheic dermatitis
erythematous patches with greasy scale on the central face
Tactuo
0.1% Adapalene (topical retinoid) and 2.5% benzoyl peroxide (60g), applied qHS or qAM
Dovobet (Betamethasone dipropionate/Calcipotriol)
Psoriasis treatment
tinea versicolor treatment
Ketoconazole 2% (Nizoral) Shampoo to skin x 5 minutes x 1 month
Topical 2.5% selenium sulfide solution (Selsun shampoo) x 10 min bid x 2 weeks
Canesten cream
tinea capitis
- Griseofulvin (Fulvicin U/F 15-20mg/kg) x 8wks
- Creams, Shampoos are ineffective, MUST have ORAL therapy
Topical benzoyl peroxide with clindamycin
(BenzaClin® by Dermik)
Topical benzoyl peroxide with erythromycin
(Benzamycin® by Dermik)
Topical retinoid with erythromycin
(Stievamycin® by Stiefel
Topical retinoid (tretinoin) plus erythromycin (Stievamycin® by Stiefel)
It should be applied to the affected areas once/day before bedtime after the skin has been thoroughly washed, rinsed and patted dry.
Topical benzoyl peroxide plus erythromycin (Benzamycin® by Dermik)
A thin layer should be applied to the affected areas 1 to 2 times/day after the skin has been thoroughly washed, rinsed and patted dry. This product must be refrigerated and may bleach clothing.
Topical benzoyl peroxide plus clindamycin (Clindoxyl® by Stiefel in Canada, Benzaclin® by Dermik)
It should be applied to skin that has been washed, rinsed and patted dry. This product does not need to be refrigerated.
superficial basal cell carcinoma differential
basal cell carcinoma, nodular; eczema, nummular; tinea corporis
dysplastic nevus differential
melanoma, superficial spreading; seborrheic keratosis
nodular BCC differential
melanoma, amelanotic; nevus, intradermal; squamous cell carcinoma
Eczema versus dermatitis
Eczema refers to an inflammatory process primarily involving the first layer of the skin. Dermatitis simply means inflammation of the skin by any cause.
