Dermatology/ Allergies Flashcards
(105 cards)
Lichen planus
Feature
Location
Shape
Rx
- itchy, papular rash
- palms, soles, genitalia and flexor surfaces of arms
- Koebner phenomenon may be seen (new skin lesions appearing at the site of trauma)
- polygonal in shape, with a ‘white-lines’ pattern on the surface (Wickham’s striae)
Rx
- Topical steroids
- Oral lesions - benzydamine mouthwash
Lichen planus Drug causes (3)
- gold
- quinine
- thiazides
Acne rosacea Features (3) Location What can cause an exacerbation of symptoms? Mx
- Flushing, telangiectasia, rhinophyma
- Typically affects nose, cheeks and forehead
- Sunlight may exacerbate symptoms
Mx Mild 1. Topical metro 2. Topical brimonidine gel for pts with flushing but limited telangiectasia Severe 3. Oxytetracycline
Pemphigus vulgaris is an automimmune condition against? Which population? Describe the lesions Biopsy findings Rx (2)
- desmoglein 3
- Ashkenazi Jewish population
- Flaccid, easily ruptured vesicles and bullae, painful, not itchy
- acantholysis
Rx steroids, immunosuppressants
itchy, tense blisters typically around flexures
the blisters usually heal without scarring
there is usually no mucosal involvement
Rx
Bullous pemphigoid
Rx PO steroids
Difference between bullous pemphigoid and pemphigus vulgaris?
Nil mucosal involvement on bullous pemphigoid
Tense blisters in pemphigoid
Flaccid easily ruptured blisters in pemphigus
Itchy in pemphigoid, not itchy in pemphigus
Pemphigus Vulgaris - not itchy, mucosal, flaccid
Bullous pemphigoid - itchy, tense, nil mucosal involvement
Rash is typically maculopapular with target lesions being characteristic
May develop into vesicles or bullae
mucosal involvement
severe systemic symptoms: fever, arthralgia
starts with flu-like symptoms, followed by a painful rash that spreads and blisters
Stevens- Johnson syndrome
Stevens- Johnson syndrome
Causes
penicillin sulphonamides anti-epileptics lamotrigine, carbamazepine, phenytoin allopurinol NSAIDs oral contraceptive pill
Name the condition
Seen in which disease?
shiny, painless areas of yellow/red skin typically on the shin
often associated with telangiectasia
Necrobiosis lipoidica diabeticorum
Name the condition
Seen in which disease?
initially small red papule
later deep, red, necrotic ulcers with a violaceous border
Pyoderma gangrenosum
IBD
Name the condition
Seen in which disease?
symmetrical, erythematous lesions
shiny, orange peel skin
Pretibial myxoedema
Grave’s
Name the condition
symmetrical, erythematous, tender, nodules which heal without scarring
Erythema nodosum
Itchy, red skin lesions, lymphadenopathy, hepatosplenomegaly
Name the condition
What is it?
Mycosis fungoides
rare form of T-cell lymphoma that affects the skin
lesions tend to be of different colours in contrast to eczema/psoriasis where there is greater homogenicity
Psoriasis: exacerbating factors
What can exacerbate guttate psoriasis?
trauma
alcohol
drugs: BB, lithium, antimalarials, NSAIDs, ACEi, infliximab
withdrawal of steroids
Streptococcal infection may trigger guttate psoriasis.
BL. STAINS
Isotretinoin is used to treat which condition?
Severe acne
Young adult with an abdominal herald patch, followed by erythematous, oval, scaly patches in a ‘fir-tree’ distribution.
Associated with which virus?
Minority have a preceding viral illness
Mx
Pityriasis rosea
Self limiting 6-12 weeks
Herpes hominis virus 7 (HHV-7)
Differentiating guttate psoriasis and pityriasis rosea
Prodrome
Appearance
Treatment
Guttate: strep throat infection 2-4 weeks prior
Pityriasis: for exam situation, will unlikley to have a virus prior
Guttate:
‘Tear drop’, scaly papules on the trunk and limbs
Pityriasis: Herald patch followed 1-2 weeks later by multiple erythematous, slightly raised oval lesions with a fine scale confined to the outer aspects of the lesions. Fir tree appearance.
Guttate: self limiting 2-3 months
Pityriasis: self limiting 6 weeks
Zinc deficiency
Features
- perioral dermatitis: red, crusted lesions
- acrodermatitis
- alopecia
- short stature
- hypogonadism
- hepatosplenomegaly
- geophagia (ingesting clay/soil)
- cognitive impairment
What is vitiligo?
Features (2)
Location (1)
autoimmune condition which results in the loss of melanocytes and consequent depigmentation of the skin
- well-demarcated patches of depigmented skin
- peripheries
- trauma may precipitate new lesions (Koebner phenomenon)
Vitiligo associated conditions
- type 1 diabetes mellitus
- Addison’s disease
- autoimmune thyroid disorders
- pernicious anaemia
- alopecia areata
Vitiligo
Mx
- Topical steroids can reverse it if used early
- Sunblock
- Phototherapy/ topical tacrolimus
Venous ulceration is typically seen where?
Mx
Above medial malleolus
Mx
1. Compression bandaging
2. Oral pentoxifylline (improves healing rate)
Venous ulceration
Ix
ABPI
Normal range 0.9 - 1.2, low or high could indicate arterial disease
Difference between arterial and venous ulcers
Arterial lateral malleolus, end of toes, tops of feet
Venous medial malleolus
Arterial punched out, necrotic, black, deep, or pale/ light pink, well demarcated
Venous edges irregular, deep pink to red, shallow
Arterial, dry, little drainage
Venous skin will be tight, drainage present, brown pigmentation