Pathology of rashes Flashcards
How will a spongiotic reaction pattern show?
Eczema.
Shows intraepidermal oedema
What does a psoriasiform pattern look like?
An elongation of the rete ridges.
Classically psoriasis
What does lichenoid pattern look like?
A basal layer damage, presenting as lichen planus or lupus.
What is a vesicobullous pattern?
Blistering in the form of pemphigoid or pemphigus.
What is rhinophyma?
Mr Wilsons nose
What can be seen in rosacea?
Recurrent facial flushing, visible blood vessels and the presence of pustules.
What are common triggers for rosacea?
Sunlight, alcohol, spicy foods, stress
What is pemphigus?
Rare autoimmune bullous disease.
Loss of integrity of epidermal cell adhesion.
Responds well to steroids.
There are 4 types of pemphigus but what is the most common?
Pemphigus vulgaris
What causes pemphigus vulgaris?
An autoimmune condition where IgG auto-antibodies are made against desmoglein 3.
What does desmoglein 3 do?
Maintains desmosomal attachments
What is acantholysis?
Loss of intercellular connections between desmosomes and results in the separation of keratinocytes.
Present in pemphigus vulgaris
What does pemphigus vulgaris look like?
fluid filled blisters which rupture to form erosions.
Involves scalp, face, axilla, groin and trunk.
May also affect the mucosa
What is bullous pemphigoid?
A subepidermal blister which does not display acantholysis
What is the pathology of bullous pemphigoid?
IgG react with an antigen of the hemidesmosomes anchoring basal cells to basement membrane.
What is a good test for bullous pemphigoid?
Immunoflurescence at DEJ.
What is dermatitis herpetiformis?
Rare condition which affects elbows, knees, buttocks.
Classically papillary microabscesses.
What other condition does dermatitis herpetiformis have a link with?
Coeliac disease.
IgA antibodies target gliadin in gluten.
Immune complexes form in dermal papillae and activate complement
What is the dermis divided into?
The papillary dermis
The reticular dermis
Where is the papillary dermis?
Just beneath the epidermis
What is contained within the reticular dermis?
Appendages structures - sweat glands, pilosebacceous units.
What type of collagen is the dermis made from?
Type 1 and type 3 collagen
What are munro microabscesses a sign of?
Psoriasis.
They are a collection of neutrophils in the keratin layer.
