Dermatology Flashcards
Erythematous, annular patches
“Wood-grain” appearance
Diagnosis? Associated with what malignancy?
Erythema gyratum repens
Associated with lung cancer
Pityriasis rosea - caused?
HHV-7
Steroid ladder + examples
Tx for acne vulgaris
(1) Topical retinoid
+/- Topical ABx +/- Oral ABx (doxycycline, erythromycin)
+/- Topical benzoyl peroxide
+/- Topical Azelaic acid
If cycle related –> COCP
If resistant –> Isotretinoin (S/E: Dry skin, eyes, mouth, nosebleeds, suicide)
Middle-aged (30-60 year old)
Triggered by Alcohol and Spicy food
**Flushing**
Papules, Pustules
Telangiectasis
Diagnosis? Treatment?
Acne rosacea
(1) Topical metronidazole
(2) Oral tetracycline or erythromycin
Inherited
Skin fragility
Blistering of skin and mucous membranes
Diagnosis? Cause?
Epidermolysis bullosa
Mutations in Laminin V
Itchy, deep, tense, bullae
No mucosal involvement
Diagnosis? Ix? Tx?
Bullous pemphigoid
Itchy, deep, tense, bullae + No mucosal involvement
IgG and C3 linear deposition at the dermoepidermal junction
Tx: oral corticosteroids
Flaccid bullae
Mucosal involvement
Diagnosis? Ix? Tx?
Bullous pemphigus (Pemphigus vulgaris, Pemphigus foliaceus)
Flaccid, superficial bullae + Mucosal involvement
Ix: auto-antibodies against desmoglein –> acantholysis
loss of intercellular connections between keratinocytes
Tx: oral prednioslone
Itchy, dry skin
Vesicles
Punched out ulcerations
Diagnosis? Cause? Treatment?
Eczema herpeticum
Caused by HSV 1/2
IV Aciclovir
Tx for treatment resistant hand dermatitis
(1) Emollients
(2) Aliretinoin
Types, Pathogenesis and Ix for contact dermatitis
Allergic contact dermatitis –> Type IV hypersensitivity reaction (sub-acute onset)
Irritant contact dermatitis –> due to friction or chemical damage (acute onset)
Ix: Patch testing
Itchy, red, scaly lesions
on head, nasolabial folds, scalp
Diagnosis? Cause? Treatment? Complications?
Seborrhoeic dermatitis
Caused by Malassezia furfur
If scalp –> Topical shampoo
If face and body –> Topical ketoconazole
Complications: Blepharitis, Otitis externa
Hot climate
Multiple, small, itchy blisters/vesicles
on fingers, palms and soles of feet
Diagnosis? Differential?
Pompholyx dermatitis
Difficult to DDx from palmoplantar pustulosis (psoriasis in other areas)
Acute onset
Target lesions
Mucosal involvement
Diagnosis? Cause? Prognosis?
Erythema multiforme
EM minor –> no mucosal involvement
EM major –> mucosal involvement
Caused by infections (HSV, Mycoplasma) or drug reactions
Good prognosis as self limiting
Painful, red, subcutaneous nodules on shins
Diagnosis? Cause? Next Ix? Prognosis?
Erythema nodosum
Causes
- Infection
- Streptococcal throat infection
- TB
- IBD
- Sarcoidosis
- Hodgkin’s lymphoma
- Pregnancy
CXR to look for sarcoidosis or TB
Good prognosis as self limiting
Hot water bottle
Ertyematous patch with areas of hyperpigmentation
Diagnosis? Next Ix?
Erythema ab igne
Often related to chronic pain ? bone metastases
Erythema marginatum
What does it look like?
Associated with?
Rheumatic fever
Erythema marginatum
Causing pink border with fading centre (central clearing)
Expanding patch of erythema
Classical bull’s eye appearance
Diagnosis? Associated with?
Erythema chronicum migrans
Lyme disease
Purple, pruritic, papular, polygonal rash
on flexor surfaces
Wickham’s striae (white reticular webs)
Diagnosis? Cause? Tx?
Lichen planus
Unknown cause ? autoimmune
Clinical diagnosis
Tx: High dose topical steroids
Elderly woman
Vulval itching
Hypopigmentation
Fragile skin / White parchment paper
Diagnosis? Tx? Complications?
Lichen sclerosus
Unknown cause ? autoimmune
Clinical diagnosis
Tx: high-dose topical steroids
Complications: Vulval cancer (5%)
Tx for pressure ulcers
Pressure-reducing aids
Repositioning
Hydrocolloid dressings + Hydrogels (moist environment encourages ulcer healing)
Triggers for psoriasis
-
Drugs
- B blockers
- Lithium
- Withdrawal or oral steroids
- Anti-malarials
- Alcohol
- Smoking
- Post-partum
- Trauma / Kobner phenomenon
Sore throat 2 weeks ago
Acute onset
Red, scaly, tear-drop lesions
Diagnosis?
Guttate psoriasis
Recent withdrawal of oral steroids
Erythema with yellow pustules
Systemic symptoms
Diagnosis?
Generalised pustular psoriasis