Rash pathology Flashcards
Roughly what is the ratio of basal cells to melanocytes?
10:1
What type of epithelium is the epidermis?
Stratified squamous keratinising epithelium
Which types of collagen are found in
a) the dermis
b) the basement membrane
a) 1 & 111
b) type 4 (+ laminin)
What are the characteristic nail changes of psoriasis?
Subungal hyperkeratosis
Clubbing
Oncholysis
Leukonychia
What feature of pemphigus distinguishes it from pemphigoid and may lead ultimately to death?
Mucosal involvement (mouth, resp. tract)
What is acantholysis?
Separation of intracellular adhesion sites, seen in pemphigus
When pemphigus lesions rupture, what is the result?
Shallow erosions on the skin
What is the result of IgG antibodies attacking the basement membrane in pemphigoid?
Local complement activation, tissue damage, separation of the epidermis from the underlying basement membrane
Which disease is dermatitis herpetiformis associated with?
Coeliac disease
What is the pathological hallmark of dermatitis herpetiformis?
Papillary dermal micro abscesses
What is the basis of the link between dermatitis herpetiformis and coeliac disease thought to be?
Cross-reactivity- IgA antibodies against gliadin also react against connective tissue matrix proteins
