Lecture 33: Skin

Question 1

Clinical Scenario 1:

17 y/o with 12month Hx of intensly itchy rash

Intermitted lasting less than 24h on all parts of body

Answer 1

Urticaria - weals (lasts less than 24h)

(nb: urticaria vasculitis is different - lasts longer and can leaving nasty bruising)

cyclosporin (immunosuppressant) was used as treatment for this patient to stop autoimmune reaction.

Question 2

Clinical Scenario 2:

80y/o lady presents with 4 month Hx of itch and recent development of blisters

Significant cognitive impairment due to multiple cerebrovascular accidents prior to onset of her skin problems

Answer 2

Bullous pemphigoid

An autoimmune disease due to the formation of IgG antibodies against hemi desomsomal proteins (that hold the epidermis to the dermis)

3 isoforms of the bullous pemphigoid antigen:

• Neural form, skin form and muscular form
• Cross reactivity between the neural and skin isoforms is possible and is linked to previous cerbrovascular injury that has damaged the normal barrier function of the BBB.

Question 3

Direct immunofluorescence?

Answer 3

After cutting out a core that includes normal and blistered skin place anti-human antibody with a fluorescent tag on it to.

This can then be viewed to see where the antibodies are

Question 4

If the antibodies were to be against proteins holding the epidermis together?

Answer 4

Phemphigus vulgaris

When autoimmune disease occurs due to IgG autoantibodies attack keratinocytes desmosome

You get superficial erosions on the centre of the chest and back as well as bad ulcers in the mouth.

Question 5

Atopic eczema?

Answer 5

In the granular layer, profilaggrin is converted to filaggrin. In many people with atopcic eczema and dry skin they have a mutation in the genes for profilaggrin.

Question 6

Clinical Scenario 3

55y/o man presents with painful rash (may have be vascularised - some beeding into them)

Hx of liver transplant 3 years prior for cirrhosis and a hepatoma

Currently on:

• 1g od Mycophenolate
• 2mg/1mg mane, nocte Tacrolimus
• (both immunosupressive drugs)

Answer 6

Diagnosis:

• Disseminated varicella zoster virus VZV (immune system would normally take care of this problem - or just result in shingles)