Flashcards in Rashes Deck (37):
Pathogensis of acne
Increased androgens at puberty
Increased androgen sensitivity of sebaceous glands
Keratin plugging of pilosebaceous units
Infection with corynebacterium acnes
Clinical presentation of rosacea
More commonly females
Recurrent facial flushing
Visible blood vessels
Tickening of skin - rhinophyma
Triggers of rosacea
What are the 3 important bullous disorders?
What is bullous pemphigus?
Rare autoimmun bullous disease resulting in loss of integrity of epidermal cell adhesion
Which subtype are 80% of pemphigus cases?
What immunology results would be indicative of pemphigus vulgaris?
IgG auto-antibodies against desmoglein 3
Pathogenesis of pemphigus vulgaris
Demsoglein (glue) contains desmosomal attachments
Immune complexes form on cell surface
Compliment activation & protease release
Disruption of desmosomes
Ending in ACANTHOLYSIS (cells float apart)
What process is common to all variants of pemphigus?
Clinical presentation of pemphigus vulgaris
Ruptured fluid filled blisters
Involves esp. scalp, face, axillae, groin, trunk
May affect mucosa
What is bullous pemphigoid?
Subepidermal blister with no evidence of acantholysis
Epidermis lifts of basement membrane
What is the findings of bullous pemphigoid on immunofluorescence?
Linear IgG & complement depositied around the basement membrane
Why is it important to always send early lesions for histology of bullous pemphigoid?
As older lesions show re-epithelialisation of their floor - mimicking pemphigus vulgaris
What is dermatitis herpetiformis?
Rare autoimmune bullous disease associated with coeliac disease
Clinical presentation of dermatitis herpetiformis
Intensely itchy symmetrical lesions
Elbows, knees and buttocks - often excoriated
Hallmark is papillary dermal microabscesses
Findings of dermatitis herpetiformis on immunofluorescence
Deposits of IgA in dermal papillae
What are the common sites involved in psoriasis?
Scalp, sacrum, hands, feet, trunk
Describe psoriasis plaques
Sharply demarcated, scaly, erythematous plaques
Psoriatic nail symptoms
What is the Koebner phenomenon?
Appearance of new skin lesions on areas of cutaneous injury
Topical treatment options for psoriasis
Vit D analogues (calcipotriol, calcitrol)
Other alternative treatment options for psoriasis
Fumaric acid ester
Morphology of acne vulgaris
Characteristics of mild acne
Scattered papules and pustules, comedones
Characteristics of moderate acne
Numerous papules, pustules & mild atrophic scarring
Characteristics of severe acne
Numerous papules, pustules, cysts, nodules and significant scarring
Topical treatment avaliable for acne
Benzoyl peroxide (keratolytic, antibacterial)
Topical vit A derivatives - adapalene (drying effect)
Topical antibiotics (antibacterial & anti-inflammatory)
Systemic treatments available for acne
Isotretinoin (oral retinoid)
What is the initial effect of isotretinoin?
Which topical antibiotic can be particularly effective in rosacea?
Which bullous disorder is nikolsky sign negative?
Which bullous disorder is more supperficial?
Which bullous disorder is more likely to involve mucosa?
Where is acne found?
Sebaceous gland sites (face, upper back, anterior chest)
Which skin disorders are associated with pregnancy?
Polymorphic eruption with pregnancy
Characteristics of pemphigoid gestationis
Pruritic blistering lesions
Rarely seen in first pregnancy
Oral corticosteroids usually required