Dermatology Flashcards
Definition of psoriasis
Common chronic inflammatory skin disorder affecting individuals with an underlying genetic predisposition.
Manifestation of psoriasis
Sharply demarcated, erythematous, scaly, pruritic plaques, most commonly occurring on the scalp, presacral region and extensor surfaces of the knees and elbows; however, any area of the skin may be affected
Other common findings include arthritis, generally affecting the fingers and lower spine and nail involvement (e.g. pitting, discolouration)
Diagnosis of psoriasis
Clinical diagnosis based on symptoms, history and presence of specific signs
Auspitz sign: appearance of small pinpoint bleeding when scales of a cutaneous lesion are scraped off (not sensitive or specific for psoriasis)
Treatment for mild, moderate and severe psoriasis
Mild: topical corticosteroids
Moderate to severe: Systemic therapy (phototherapy, biologic agents)
History taking questions for skin conditions
Where
When (how long)
Medications?
Infectious/other people with similar rash
History of dermatitis - occupational Hx, family Hx, new or recent exposures
Common types of face rash
Rosacea
Impetigo
Atopic dermatitis
Psoriasis
Photosensitivity
Acne
Cancer
Viral exanthem
Common types of scalp rash
Psoriasis
Seborrheic dermatitis
Pediculosis
Tinea
Chicken pox
Common type of nail rash
Psoriasis
Tinea
Common type of flexure rash
Atopic dermatitis
Psoriasis
Seborrheic dermatitis
Tinea
Candida
Pediculosis
Rashes that will be present months
Tinea
Psoriasis
Atopic dermatitis
Pityriasis versicolor
Warts
Cancers
Skin infiltrations e.g. granulomata, xanthoma
Rashes that are like to be present weeks-months
Viral exanthem
Impetigo
Herpes zoster/simplex
Scabies
Drugs
Pediculosis (lice)
Pityriasis rosea
Candidiasis
Tinea
Rashes that are likely to be present hours-days
Uticaria
Contact/allergic dermatitis
Insect bites
Atopic dermatitis
Viral exanthem
Match the skin terminology:
- Bulla
- Papule
- Nodule
- Vesicle
- Plaque
- Macule
- Maculo-papule
- Patch
A. flat, circumscribed area of altered skin colour < 1 cm in diameter
B. fluid filled blister < 1 cm in diameter
C. a raised and discoloured circumscribed lesion
D. flat topped palpable mass > 1 cm in diameter
E. fluid filled blister > 1 cm in diameter
F. circumscribed palpable lump > 1 cm in diameter
G. palpable lump < 1 cm in diameter
H. flat, circumscribed area of altered skin colour > 1 cm
- E
- G
- F
- B
- D
- A
- C
- H
Where will erythema multiforme usually appear?
Palms, soles, genitals, mouth, extensor surfaces of arms and legs
Causes of erythema multiforme
Idiopathic (up to 30%)
Virus (commonly herpes simplex)
Mycoplasma
Medications (sulphur, trimethoprim, penicillin, thiazides, allopurinol, anticonvulsants)
Immunisations
How long does erythema multiforme usually last?
10-20 days, usually self limiting
Causes of erythema nodosum
Idiopathic (40%)
Sarcoidosis
Infections; strep throat, viral, TB, leprosy, fungal infection
Drugs; sulphonamides, tetracyclines, OCP
Inflammatory bowel disorders
Pregnancy
How long does erythema nodosum last?
Usually 3-8 weeks
History taking questions for skin lesions
Previous skin cancers
Previous excisions
Family Hx
Occupation
Level of sun exposure and sun protection
Any other spots of concern
Where will a seborrheic keratosis usually present?
Face and trunk
Description of a basal cell carcinoma
Pearly, fleshy papule or nodule with depressed or umbilicated centre and telangectasia
Description of squamous cell carcinoma
Thickened, red, scaly spot that may bleed and ulcerate over time. Grows over a period of months and is often tender or painful
May arise in premalignant lesion (e.g. solar keratoses, chronic ulcers, burns, leukoplakia)
System to describe melanoma
A: asymmetry
B: border; usually irregular
C: colour; variable
D: diameter; >6mm
E: elevation; can be small raised lump
for nodular melanoma
F: firmness; firm to touch
G: grows quickly; r/v if progressive growth >1 month
