Session 4: Dermatology Flashcards
What are the key components int he structure of normal skin?
EPIDERMIS:
cell types
- keratinocytes = protective barrier
- langerhans cells = a.p.c
- melanocytes = produce melanin which provides pigment to skin and protects cell nuclei from UV DNA damage
- merkel cells = contain specialised nerve endings for sensation
layers
CAN LITTLE GUYS SPROUT BIG DICKS
average epidermal turnover is 30 days
DERMIS:
composed of collagen, elastin and glycosaminoglycans for strength and elasticity, immune cells, nerve cells, skin appendages, lymphatics and blood vessels
What are the functions of skin?
protective barrier against environmental insults, thermoregulation, sensation, vitamin D synthesis, immunosurveillance, cosmesis
How do you take a dermatological history?
- Presenting complaint - nature, site and duration
- history of presenting complaint - initial appearance and evolution, symptoms, aggrevating and relieving, previous and current treatments
- past medical history - systemic diseases, history of atopy (ashma, hayfever, eczema), histroy of skin cancer or sunburns/beds/bathing, skin type
- family history - of skin disease, family history of atopy and autoimmune disease
- social history - occupation: sun exposure, contactants
- drug history - regular and recent, systemic and topical
- ICE
How do you describe the distribution of the lesions?
Acral means affecting the distal portions of limbs (hand, foot) and head (ears, nose).
Blaschko’s lines means that lesions follow a segmental pattern described by Blaschko and this is thought to suggest somatic mosaicism.
Dermatomal means corresponding with nerve root distribution, as with shingles.
Flexural means occurring in the flexor surfaces, such as the antecubital fossa and back of the knee, whilst extensor is occurring on the extensor surfaces, such as over the tip of the elbow and usually just below the patella.
Herpetiform means grouped umbilicated vesicles, as seen in herpes simplex and herpes zoster infections.
Morbilliform means that the patient has a rash that looks like measles.
Seborrhoeic refers to the areas generally affected by seborrhoeic dermatitis, with a tendency to oily skin or seborrhoea. They include the scalp, behind the ears, eyebrows, nasolabial folds, sternum, natal cleft and interscapular region.
Truncal means affecting the trunk and (rarely) the limbs.
How do you systematically describe pigmented lesions?
ABCD Asymmetru Border colour diameter
How do you systematically describe a skin complaint?
SCAM S - site, distribution, size and shape C - colour A - associated changes M - morphology
What is the history, key presenting features and management of psoriasis?
Peaks of 15-25 years and 50-60 years, usually caucasians
symmetrically distributed, red, scaly plaques usually silvery white with well defined edges with a moist peeling surface
mostly on scalp, elbows and knees
itch usually mind but can be severe and leading to scratching and lichenification, thickened leathery skin and increased skin markings
may leave brown or pale marks which will fade over months
not smoking, avoid alcohol, maintain optimal weight, treated with topical agents and perhaps with phototherapy (light therapy) and if severe a systemic corticosteroid
What is the history, key presenting features and management of eczema/dermatitis?
very itchy
red rash which may be blistered and swollen or longstanding irritation and often darker and thickened
treated with bathing with lukewarm water and soap free cleanser, wear smooth and cool clothes, protect your skin from irritants, apply an emollient and topical steroid cream, pimecrolimus cream, antibiotics, antihistamines, systemic steroids
What is the history, key presenting features and management of acne vulgaris?
mainly adolescents
mostly face may spread to involve neck, chest and back
lesions centered on pilosebaceous unit
Superficial lesions
Open and closed comedones (blackheads and whiteheads)
Papules (small, tender red bumps)
Pustules (white or yellow “squeezable” spots)
Deeper lesions
Nodules (large painful red lumps)
Pseudocysts (cyst-like fluctuant swellings)
Secondary lesions
Excoriations (picked or scratched spots)
Erythematous macules (red marks from recently healed spots, best seen in in fair skin)
Pigmented macules (dark marks from old spots, mostly affecting those with dark skin)
Scars of various types
in darker skin - less redness, more postinflammtory hyperpigmentation which persists after acne lesion gone
treated with topical anti acne preparations, lasers and light tetracylcines or antiandrogens such as birth control pill
How do you describe epidermal changes?
Desquamation - skin coming off in scales.
Psoriasiform - large white or silver flakes, as in psoriasis.
Pityriasiform - a branny powdery scale.
Lichenoid - when scale is tightly adherent to the surface of the skin.
Keratotic - horny scale with plenty of keratin.
Exfoliation - peeling off of skin.
Maceration - moist peeling skin.
Verrucous - resembling a wart.
what are 2 epidermal disorders?
plaque psoriasis
vitilligo
what are 2 dermal disorders?
dermatographia
hives
where are apocrine and eccrine glands found?
apocrine = following puberty in axillae, areolae, genitalia and anus eccrine = widespread
what are 2 types of balding patterns?
alopecia areata and male pattern balding
what are 2 conditions that affect the nails?
melanoma or fungal infections
