Derm facts

Question 1

In sunscreen, which bands do PABA and Avobenzone block?

Answer 1

PABA: UVB
Avobenzone: UVAI and UVAII

Question 2

What is Acantholysis? and suprabasal blisters?

Answer 2

Acantholysis is loss of desmosomes (lysis of stratum spinosum). Pemphigus vulgaris.

Question 3

Microabscesses on tips of dermal papillae? Association?

Answer 3

Dermatitis herpetiformis. Celiac sprue.

Question 4

What is acanthosis? Which disorder?

Answer 4

Increase in thickness of stratum spinosum. Psoriasis.

Question 5

What is dyskeratosis? Which disorder?

Answer 5

Abnormal, premature keratinization of keratinocytes - strongly eosinophilic with basophilic nuclear remnant. Squamous cell carcinoma.

Question 6

Define Hyperparakeratosis. Which disorder?

Answer 6

Retention of nuclei in stratum corneum - increased cell turnover. Normal in mucous membranes. Psoriasis in skin.

Question 7

Define Hypergranulosis. Which disorder?

Answer 7

Lots of granules in the stratum granulosum. Lichen planus.

Question 8

Define Spongiosis. Which disorder?

Answer 8

Epidermal accumulation of transudate (edema fluid). Eczematous dermatitis.

Question 9

Define dermal edema. Which disorder?

Answer 9

Excess transudate in dermal lymphatic channels. Urticaria (hives).

Question 10

Microabscesses present in which disorders?

Answer 10

Mycosis fungoides (CD4+ T-cell lymphoma) has pautrier microabscesses
psoriasis has munro microabscesses

Question 11

What causes appearance of wrinkles in aging?

Answer 11

Loss of collagen fibrils.

Question 12

Psoriasis therapy?

Answer 12

Topical vitamin D - inhibits keratinocyte proliferation
Cyclosporine - inhibits T-cell IL-2 release
Etanercept - treats plaque-type psoriasis
Methotrexate - kill rapidly proliferating keratinocytes
Ustekinumab - anti-IL-12 and IL-23

Question 13

Active ingredient in poison ivy et al?

Answer 13

Urushiol. Causes a type IV hypersensitivity reaction.

Question 14

Atopic dermatitis - mechanism, sx. Vs dermatitis herpetiformis: where on the body?

Answer 14

Atopic dermatitis: lichenification, intense pruritus, trunk and flexor surfaces. Due to filaggrin mutation, skin barrier ineffective, type I hypersensitivity
Dermatitis herpetiforms: extensor surfaces.

Question 15

necrolytic migratory erythema. What is it associated with?

Answer 15

Glucagonoma. Blistering rash around lips and lower abdomen/perineum.

Question 16

What is rosacea?

Answer 16

Persistent facial redness, telangiectasia, susceptibility to sunlight.

Question 17

Lichen simplex chronicus vs lichen sclerosus

Answer 17

LSC: too much vag scratching. leathery
LS: atrophy, squamous cell carcinoma