Introduction to General Dermatology

Question 1

true or false:

the skin contains adnexal structures

Answer 1

true- hair, nails, glands and sensory structures

Question 2

what is the hair cycle?

Answer 2

Anagen
active growingphase
80-90% of hair

Catagen
2–3 week phase growth stops/follicle shrinks
1–3% of hairs

Telogen
resting phase for 1–4 months
up to 10% of hairs in a normal scalp

Question 3

what are the functions of the skin?

Answer 3

Thermoregulation
Insulation, Heat transfer

Skin immune system
Innate and Adaptive functions

Barrier
Protects against Mechanical, Chemical, microorganisms, Ultraviolet light
Keeps in water and Electrolytes, Macromolecules

Sensation
Temperature, touch and pain

Vitamin D synthesis
UV light converts 7-dehydrocholesterol to cholecalciferol

Interpersonal Communication
Physical appearance, smell, self -identity

Question 4

why is skin disease so important?

Answer 4

Disfigurement
Discomfort
Disability
Depression
Death

Question 5

what are the external causes of skin diseases?

Answer 5

Temperature, UV, chemical (allergen or irritant), infection, trauma

Photosensitivity
Commonly caused by medications
Exposed sites affected
Can be sensitive to UVA, UVB, visible light or a combination of these.

Cold Injury
Frostbite, Chilblains
Skin Necrosis

Cold Urticaria

Dermatitis Artefacta

Question 6

what are the internal causes of skin disease?

Answer 6

Systemic disease, genetics, drugs, infection

Bullous Pemphigoid

Question 7

what are ways to describe skin lesions?

Answer 7

Macule - Small circumscribed area 
Patch -Larger circumscribed area
Papule -Small raised area
Plaque- Larger Raised area
Vesicle -Small Fluid filled
Bulla -Large Fluid filled

Pustule-Small Pus filled
Abscess- Large Pus filled

Erosion-Loss of Epidermis
Ulcer -Loss of Epidermis and dermis

Question 8

what are the most common skin conditions?

Answer 8

acne
psoriasis
rosacea
skin lesions
urticaria
warts
leg ulcers
scalp/nail disorders
eczema
infections

Question 9

what is the condition associated woth insulin resistance, obesity, malignancy?

Answer 9

Acanthosis Nigricans

Question 10

what are investigations in dermatology?

Answer 10

Charcoal swab

Ask for MC&S
Microscopy
Culture
Sensitivities

Question 11

what would you do if a viral infection is suspected?

Answer 11

Viral swab for PCR
Can swab vesicle/bulla if vesicular eruption
If systemic illness, can take throat swab

Question 12

what would you do if a fungal infection is suspected?

Answer 12

Skin scraping
Nail clipping
Hair sample

Fungal cultures