Eczemas and Allergic Skin Diseases 1

Question 1

Irritant

Answer 1

offending agent that is toxic to the skin and produces inflammation in all patients; limited to area of exposure

Question 2

Allergen

Answer 2

offending agent that produces reaction in some patients; reaction may spread beyond site

Question 3

Hypersensitivity

Answer 3

local or generalized reaction following contact with specific allergen

Question 4

Immediate hypersensitivity response

Answer 4

appears within minutes of exposure, IgE mediated; type 1 reaction (uticaria, anaphylaxis, drug/food allergy)

Question 5

Delayed hypersensitivity response

Answer 5

appears 48-72 hours after exposure; indicated cell-mediated (T cells) response; Type IV (4) (contact dermatitis, tuberculin skin test)

Question 6

Cytotoxic Antibody IgG/IgM

Answer 6

Type II - transfusion rx, Rh incompatibility

Question 7

Immune complex reaction

Answer 7

Type III - Lupus, Polyarteritis nodosa

Question 8

Irritant Contact Dermatitis (ICD)

Answer 8

disruption of skin barrier through mechanical or chemical exposure; localized (type 1)

Question 9

Common ICD irritants

Answer 9

soaps, detergents, cement, petroleum, acetone, fiberglass, wool

Question 10

Acute ICD

Answer 10

single exposure damaging keratinocytes- painful sensation, burning

blistering-> erosion-> crusting-> scaling-> necrosis-> shedding-> ulceration->healing

Question 11

Chronic ICD

Answer 11

most common; painful burning and itching, seen on hands exposed to wet work

chapping->hyperkeratosis with scaling->fissures and crusting

Question 12

Management of ICD

Answer 12

use gloves, remove irritant, use Burrow’s solution for burning, apply emollients (petroleum jelly/creams), severe acute cases benefit from oral glucocorticoids

Question 13

Allergic Contact Dermatitis (ACD)

Answer 13

re-exposure to a substance a person is sensitized to; can remain confined to site or in strong sensitization may spread. EX allergans-creams, nickel, makeup, plants

erythema->papules->vesicles->erosions->crusts->scaling
*papules are often indicative of ACD and not usually seen in ICD

Question 14

Management of ACD

Answer 14

Burrow’s solution, topical steroids (ointments preferred)

If severe use oral prednisone (start on high dose and taper down 2-3 wks)

Question 15

Allergic Phytodermatitis

Answer 15

ACD (Allergic Contact Dermatitis) due to plants. ex- poison ivy, poison oak and poison sumac

contaminated skin should be washed within 30 minutes to get rid of the oleoresin (oil)

Question 16

Atopic Dermatitis

Answer 16

“Eczema” itchy dry skin
inflammation of the skin on face and flexor surfaces
often in infancy or early childhood
may be seen as a triad with asthma and rhinitis
mixed type I and IV

Question 17

Atopic means

Answer 17

hereditary tendency towards allergic reactions

Question 18

Atopic Dermatitis management

Answer 18

Usually diminishes as child grows, 10% lifelong persistance
prevent from rubbing and scratching is essential
use emollients/moisturizers
can use prick test or RAST to identify food allergy causing it
can use topical calcineurin inhibitor (off label for less than 2 with good results)
can use crisaborale 2% ointment
severe cases can use both

**a balanced approach to long term management is recommended

Question 19

Lichen Simplex Chronicus

Answer 19

a chronic patch from repetitive rubbing or scratching
occurs in adults, many have a history of atopic dermatitis (AD)
may appear as confluence of papules or solid plaque

Question 20

Lichen Simplex Chronicus management

Answer 20

Stop rubbing or scratching
topical steroids under an occlusive dressing
antihistamines at night to prevent scratching

Question 21

Dyshidrosis (Dyshidrotic Eczematous Dermatitis, DED)

Answer 21

A type of vesicular eczema; most commonly characterized by vesicles on dorsum of the hand
Exacerbating factors may exist friction, cold, excessive exposure to water

Question 22

Dyshidrosis management

Answer 22

Topical steroids with occlusive dressing

Question 23

Nummular Eczema

Answer 23

A type of eczema with a characteristic coin shape
on forearms and calves, rare in children

treatment is moisturizers and topical steroids

Question 24

Pityriasis Alba

Answer 24

A mild type of atopic dermatitis, presents as hypo pigmented macules on the face and neck pf preadolescent
triggered by sun exposure, bathing, heat
avoid triggers, topical steroids

Question 25

Stasis Eczema (stasis dermatitis)

Answer 25

skin breakdown seen in adult patients

hyper pigmentation, scaling patches, possible ulcers with edema on lower extremities