Chronic Skin Disorders (Pathophysiology) - Block 1

Question 1

What is atopic dermatitis?

Answer 1

Chronic, recurring, itchy inflammatory disorder associated with increased serum immunoglobin E (IgE)

Question 2

What is the cause of atopic dermatitis?

Answer 2

Gene mutation in the FLG gene
1. Loss of filaggrin causes loss of barrier function in skin

Question 3

What is filaggrin?

Answer 3

Proteins that bind keratin to dermis

Question 4

What is the immune dysfunction of atopic dermatitis?

Answer 4

Humoral: Increase IgE and sensitization
Cell mediated: Predominance of Th2 cells that produce inflammatory cytokines

Question 5

How can filaggrin mutations cause inflammation?

Answer 5

Release of TSLP (Thymic stromal lymphoprotein)

Question 6

How can the environment cause atopic dermatitis?

Answer 6

1. Flare ups
2. Low humidity
3. Dysfunction of epidermal barrier and immune systems make AD patients more susceptible to infection (bacterial, HSV, fungal, Eczema herpeticum)

Question 7

What are the sx of atopic dermatitis?

Answer 7

1. Pruritis (eczematous)
2. Excoriations: Surface injuries to skin that remove cell layer.
3. Lichenification: Thick, leathery skin
4. Xerosis: Abnormal dryness

Question 8

Whar is psoriasis?

Answer 8

Chronic, complex, multifactorial, inflammatory skin disease that is immune mediated

Question 9

What are the causes of psoriasis?

Answer 9

Genetic: PSORS1: Highest risk for susceptibility; contains HLC-Cw6 allele thought to be most likely to cause psoriasis
* IL-23/Th17 pathway
* Innate immunity genetic variants: changes expression of antiviral genes and cause overporduction of cytokines
* Gene deletions linked to poor skin repair after injury

Question 10

How are lesions formed?

Answer 10

Hyperproliferation of keratinocytes that decreased cell turnover

Formation: Keratinocytes proliferate thickening the skin

Question 11

What are the sx of psoriasis?

Answer 11

1. Plaques from Koebner phenomenon
2. Auspitz sign: Pinpoint bleeding that occurs from increased vascularization of lesions when scale is lifted
3. Psoriatic arthritis
4. Nail psoriasis
5. Exacerbations of flare-ups

Question 12

What are benign neoplasms?

Answer 12

Abnormal cells that multiply more than normal or do not die when they should; noncancerous types of tissue proliferation.
Examples: moles, lipomas, actinic keratosis

Question 13

What is photodermatitis?

Answer 13

Photosensitivity; occurs when immune system reacts to UV light after exposure to sunlight or tanning device

Question 14

What is solar urticaria?

Answer 14

Pale, raised plaques on skin; hives; brought on by photosensitivity

Question 15

What is porphyria?

Answer 15

Enzyme deficiency that allows heme to accumulate

Question 16

What are the cuases of Photodermatitis?

Answer 16

1. Immune response to UV rays
2. Sun exposure may inactivate or destroy epidermal Langerhans cells that supply some skin immunity
3. Photoallergy
4. Phototoxicity
5. Polymorphous light eruptions (PMLEs)

Question 17

What is Polymorphous light eruptions (PMLEs)?

Answer 17

Reactions to light not associated with drugs or systemic disease

Question 18

What is a hemangioma?

Answer 18

Congenital lesion found on infants

Question 19

What are moles?

Answer 19

Nevis

Question 20

What are skin tags?

Answer 20

acrochordons that are soft papules on staly found in areas where skin rubs on skin

Question 21

What are the causes on hemangiomas?

Answer 21

Made up of extra blood vessels concentrated in area within or just under skin

Question 22

What are the cuases of moles?

Answer 22

Made up of altered melanocytes that proliferate and grow in clustes

(Sun exposure may cause it to become cancerous)

Question 23

What are the sx of hemangiomas?

Answer 23

Lesions

Question 24

What are sx of moles?

Answer 24

Dysplactic nevi (irregular shape, multicolored, asymmetric)

Question 25

Sx of skin tags?

Answer 25

Pedunculated papules

Question 26

What is alopecia?

Answer 26

Baldness or loss of hair from scalp or body

Question 27

What is androgenic alopecia?

Answer 27

Genetic type of baldness related to hormone androgen

Question 28

What are the causes of alopecia?

Answer 28

1. Scarring
2. Non scarring: Trichotilliomania: Obsessive-compulsive hair pulling
3. Androgenic alopecia

Question 29

What is alopecia areata?

Answer 29

Autoimmune disorder that causes chronic, relapsing, inflammatory-induced, nonscarring hair loss and nail changes

Question 30

What are the causes of alopecia areata?

Answer 30

Inflammatory cells attack hair follicles: Cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) or family history of AA

Question 31

What are the types of Alopecia Areata (AA)?

Answer 31

Alopecia totalis (AT): Complete baldness of scalp.
Alopecia universalis (AU): Hair loss over entire body; fewer cases than alopecia totalis.