Pathology Flashcards
What are the four main inflammatory skin patterns?
Give an example of each.
- Spongiotic - intraepidermal oedema e.g. eczema (see Dr Brown’s eczema lecture)
- Psoriasiform - elongation of the rete ridges e.g. psoriasis
- Lichenoid - basal layer damage e.g. lichen planus and lupus
- Vesiculobullous-blistering e.g. pemphigoid, pemphigus and dermatitis herpetiformis
What are the two main pathological problems in psoriasis?
Acanthosis of the epidermis
Parakeratosis (nuclei persist in the surface keratin)
What is the Koebner phenomenon?
New lesions of psoriasis arise at sites of trauma
What is the genetic influence in psoriasis?
Unclear - associated with specific HLA types
Which inflammatory cells are there in psoriasis?
No infection, but neutrophils gather in the epidermis, suggests that complement is activated in psoriasis which draws the neutrophils.
What is the problem in erythrodermic psoriasis?
Patients die from oozing fluid from the skin which causes metabolic problems
What is psoriasiform?
Histology – the ridges are elongated and fused; often become clubbed at the base – known as psoriasiform. May also get neutrophils in the corneal layer.
Which layer of the skin is affected in lichenoid disorders?
Basal layer of epidermis
What is the main clinical feature in lichen disorders?
Itchy flat topped violaceous papules
- Irregular sawtooth acanthosis
- Hypergranulosis and orthohyperkeratosis
- Band-like upper dermal infiltrate of lymphocytes
- Basal damage with formation of cytoid bodies
Which disease is this?
Lichenoid disorder
Immunobullous disorders
- Main clinical feature?
- Give three examples
Blisters
- Pemphigus
- Bullous pemphigoid
- Dermatitis herpetiformis
Pemphigus
- What type of disease?
- Epidemiology?
- Histology?
- Severity?
- Treatment?
- Types?
- Most common type?
- Rare autoimmune bullous disease
- Sex incidence is equal, usually middle -age
- Loss of integrity of epidermal cell adhesion
- Variable severity - occasionally fatal
- Responds to steroids
- Pemphigus has four distinct types which are separable clinically and histologically.
The most common is pemphigus vulgaris.
Pemphigus vulgaris
- Which antibody?
- What forms on cell surface?
- Disruption of which structures?
- End result?
- IgG auto-antibodies made against desmoglein 3
- Immune complexes form on cell surface
- Disruption of desmosomes
- End result is ACANTHOLYSIS
Pemphigus vulgaris
- Which areas of the body are affected?
Scalp, face, axillae, groin, trunk. It may affect mucosa e.g. mouth, resp.tract. Extensive mucosal involvement may be fatal. It produces fluid filled blisters which rupture to form shallow erosions.
What pathology is common to ass variants of pemphigus?
Acantholysis = lysis of intercellular adhesion sites
