Skin: Clinical examples and experimental evidence

Question 1

Friction Blisters explained

Answer 1

Lymph filled spaces between epidermis and dermis of thick skin by excessive rubbing

Question 2

Albinism explained

Answer 2

Congenital disorder producing skin hypo-pigmentation. Causes a mutation affecting the tyrosinase enzyme preventing the catalysis of tyrosine into melanin.

Question 3

What gene is affected + function?

Answer 3

P gene which encodes a scaffold protein for tyrosinase, TRP1 and TRP2 in eumelanosomes.

Question 4

Pemphigus explained

Answer 4

Blistering disorder caused by autoimmune damage to intercellular junctions between keratinocytes. Attack certain desmosomes.

Question 5

Another junctional complex disease

Answer 5

Bullous pemphigoid- abnormality between epidermis-dermis layers

Question 6

Keratin disorder explained

Answer 6

Epidermolysis Bullosa simplex- dominant mutations in keratins, resulting in a failure in keratinisation, which affects the skins ability to resist mechanic stress, thus causing blistering of the skin.

Question 7

Basal cell carcinoma explained

Answer 7

Thought to originate from folliculo-sebaceous-aporcine germ causing lesions in the skin.

Question 8

Melanoma explained

Answer 8

Dividing rapidly, malignantly transformed melanocytes that often penetrate the basal lamina and enter the dermis. Metastasise and invade blood and lymphatic vessels.

Question 9

Psoriasis explained

Answer 9

Chronic skin condition where keratinocytes differentiate and are produced at accelerated rates, causing thickening of the epidermal layers. Increase keratinisation and desquamation.

Overactive T-lymphocytes trigger an autoimmune reaction in the skin which lead to inflammation with redness, irritation, itching and scaling.