eczema and dermatitis

Question 1

what are Allergic and Hypersensitivity Dermatoses?

Answer 1

• Involve the inflm response to multiple exogenous and endogenous agents
• Disorders- characterized by epidermal edema with separation of epidermal cells, include irritant contact dermatitis, allergy contact dermatisi, atopic and nummular eczuma, urticardia, and drug-induced skin eruptions

Question 2

what are the two forms of contact dermatitis

Answer 2

• Two types of contact dermatitis:

o Allergic and irritant

Question 3

describe allergic contact dermatitis

Answer 3

• cell-mediated, type IV hypersensitivity response brought about by sensitization to an allergen

Question 4

what is type IV hypersensitivity
mediated by?

what are the 2 types? which type is contact dermatitis

Answer 4

.t cell hypersensitivity rxn

the macrophage presents Ag to T cell. The T cell is sensitized then cytotoxic T cells destroy Ag bearing cells which causes inflm damage.

types:

• direct
• delayed (days, d/t the production of lymphokines) this is like contact dermatitis

Question 5

what kind of things is pt having allergic contact dermatitis to

Answer 5

• Additives such as dyes and perfumes are major sources known for allergens
• More than 2000 allergens
• Common topical agents causing allergic rashes are antimicrobial agents, antihistamines, local anesthetic agens, preservatives, and adhesive tape
• Additional examples: poison oak, ivy, jewelry and latex

Question 6

with allergic contact dermatitis what is the quality of the lesions
where can they appear
why is this important

ahmed says do not describe lesions in detail!!

Answer 6

• Lesions range from milk erythema with edema to vesicles or large bullae
• Secondary lesions from bacterial infection may occur
• Can occur anywhere in the body (classified by location ie. hand eczema)
• Location and pattern help to identify the agent (ie. typical poison ivy lesion consists of vesicles or bullae in a linear pattern from swiping the plant on exposed areas)
o The vesicles and bullae break and weep, leaving an excoriated area

Question 7

what is atopy

Answer 7

.Atopy refers to the genetic tendency to develop allergic diseases such as allergic rhinitis, asthma and atopic dermatitis (eczema

Question 8

what is irritant contact dermatitis

Answer 8

• Caused by chemicals that irritate the skin

* Can occur from mechanical means such as rubbing, chemical irritants (household products), env’t irritants (plants)

Question 9

what is the allergen for irritant contact dermatitis

what puts you at risk of this form of dermatitis

Answer 9

• No allergens can be identified
• A hx of atopic dermatitis, either in the past or concurrent, is a major risk in the development of irritant contact dermatitis.