Keratin & collagen

Question 1

What is keratin?

Answer 1

Diverse structural proteins for intermediate filament network

Question 2

How many keratin families? Divided in?

Answer 2

30 different keratin families

➤ acidic or basic

Question 3

Functions of keratin?

Answer 3

o Influence architecture and mitotic activity of epithelial cells
o Scaffold aids to sustain mechanical stress, maintain structural integrity, mechanical resilience, protects against hydrostatic pressure
o Involved in cell signalling, cell transport, cell differentiation, apoptosis
o Influence metabolic processes
o Transport of vesicles

Question 4

Keratin - Disease result as a mutation of …

Answer 4

Occur as a result of mutation in the genes encoding the keratin protein

Question 5

Examples of keratin related disorders?

Answer 5

o Epidermolysis bullosa (EB): large heterogeneous diseases- 1,000 mutations- increased fluid filled blister formation
o Epidermolysis bullosa simplex (EBS): numerous mutations some very rare forms are lethal- blistering with secondary infections often issue
o Mutations in hair and nails

Question 6

Give an example of disorder of keratin associated proteins

Answer 6

Pemphigus

Question 7

What is pemphigus? What does it affect? What is the treatment?

Answer 7

• Pemphigus affects skin and mucus membrane often affects pressure points
• Autoimmune disease ➤ intraepithelial blistering disease.
• Lesions later become dry and hyperkeratotic and fissured.
• Can be life threatening affect desmosomes.
• Tx: corticosteroids (local and systemic) and other immunosuppressive agents and supportive therapies

Question 8

What can cause pemphigus? How does it resolve?

Answer 8

o Can get drug induced pemphigus- days, weeks or months after prescription
o Rare – 200 cases in literature
o Drugs include- Thiol drugs includes enalapril; Antibiotics- penicillin, vancomycin, cephalosporins; Antihypertensive drugs; piroxicam

o 50% resolve when medication withdrawn, otherwise treatment corticosteroids

Question 9

How many people are affected by psoriasis? Which gender?

Answer 9

Psoriasis –affects 20% of the population occurs both genders

Question 10

Is psoriasis infectious?

Answer 10

No

Question 11

What is psoriasis link to?

Answer 11

T cells malfunction

Question 12

When is psoriasis onset?

Answer 12

Onset anytime but more common in second and third decades- can have periods of remissions- worse in winter

Question 13

What is the distribution of psoriasis?

Answer 13

Symmetric distribution lesions elbows scalp knees- plaques slivery in appearances

Question 14

Those with moderate to severe psoriasis can also present with what?

Answer 14

30% inflammatory arthritis - swelling and stiffness in the joints. Can affect any joint.

Question 15

People suffering from psoriasis are at increased risk of what?

Answer 15

anxiety
depression
heart d/s
stroke

Question 16

What can trigger psoriasis?

Answer 16

• Certain medications can cause psoriasis to flare- beta blockers, lithium
• Other triggers: infections, stress and/or alcohol, smoking, vit D deficiency, injury to skin

Question 17

Risk factors for psoriasis

Answer 17

o	Family Hx 
o	Viral and bacterial infections- HIV recurrent strep infections 
o	Stress 
o	Obesity 
o	Smoking

Question 18

Signs & symptoms of psoriasis

Answer 18

o Worsening of long term erythematous scaly area
o Sudden area of small areas of scaly redness
o Recent strep infection, trauma, immunization, viral infection,
o Pain (psoriatic arthritis)
o Pruritus
o Can affect eye lids- corneal involvement rare

Question 19

Psoriasis - Tx

Answer 19

o Topical: corticosteroids, vitamin D and vitamin D analogues, tar preparations etc
o Second line: phototherapies and systemic non-biological agents e.g. methotrexate
o Third line: systemic biological therapies TNF antagonists

Question 20

Psoriasis - Cx

Answer 20

o	Secondary infections
o	Psoriatic arthritis
o	Mitral valve prolapse
o	Increased risk of lymphoma
o	Increased risk CVD and IHD

Question 21

Types of psoriasis

Answer 21

• Scalp
• Inverse (under the breast, groin, armpits) ➤ smooth ,dry & well-defined salmon-coloured patches
• Erythrodermic (entire body surface) ➤ scales + itch
• Nails (finger + toes) ➤ become pitted, discoloured, thickened and loose
• Guttate (trunk, torso, face) ➤ not as red or scaly as plaque psoriasis and looks like ‘droplets’ on the skin
• Pustular (thumb, palm of fingers and soles of the feet) ➤ large fluid-filled blister-like areas
• Plaque (knees, elbows, lower back, ears, scalp) ➤ red plaques surrounded by white silvery scales, itchy and sore

Question 22

Itchthyosis - What is it?

Answer 22

Continuous scaling affects the whole body

Question 23

Itchthyosis - caused by what?

Answer 23

• Mostly congenital but rare forms due to malignancy, nutritional deficiency, infection, autoimmune
• Abnormal epidermal differentiation
• Barrier function is compromised ➤ decreased ability to protect
• Mutations in over 50 genes ➤ alter host of cellular activities

Question 24

Itchthyosis - types

Answer 24

• Non syndromic includes Ichthyosis vulgaris (IV) 1 in 250 births typically mild- autosomal dominant in filaggrin gene - epidermal differentiation and barrier
• Syndromic - eg affect least 1 other organ eg Sjögren Larsson syndrome

Question 25

Itchthyosis - Tx

Answer 25

o No cure ➤ manage
o Twice daily intensive use of moisturisers can contain antiseptics/antibiotics
o Sometimes use of retinoids

Question 26

Disorders of collagen - example?

Answer 26

Elhers-Danlos syndromes

Question 27

What is the most abundant protein?

Answer 27

90% collagen type I

Question 28

Disorders of collagen - how many types described?

Answer 28

28

Question 29

EDS - what is it? S&S? Management?

Answer 29

o Group rare inherited conditions that affect connective tissue
o Increased ROM
o Stretchy skin which bruises easily
o Fragile skin but other issues in some mutations include rupture of arteries, organs blood vessels depending on mutation
o Can be mild or severe causing disabilities and death
o Advised to help maintain their health – avoid contact sport, care with heavy lifting, wear protective clothing