Midterm 2- allergic lid diease Flashcards
Type I rxn
immediate type reaction:
Reaction resulting from the release of pharmacologically active substances such as histamine, or eosinophillic chemotactic factor (ecf) from IgE-sensitized basophils and mast cells after contact with specific antigens
Occurs within minutes to hours
Type IV
delayed type reaction:
Reactions caused by sensitized lymphocytes (T-cells) after contact with antigens which result from direct cytotoxicity or from the release of lymphokines
Cell-mediated reaction
Occurs over hours to days
Dennie–Morgan fold (aka Dennie-Morgan line)
A fold or line in the skin below the lower eyelid caused by edema in allergic dermatitis
CONTACT DERMATITIS definiton
Very common immunological disease
Results from direct contact with environmental allergen
Episodes can be triggered by specific events
Dermatitis
any inflammation of the epidermis
Contact dermatitis
any skin inflammation that occurs when the skin surface comes in contact with a substance originating outside the body
Irritant Contact Dermatitis
- More common
- Contact with substance that directly damages skin
- Nonspecific response of skin to chemical damage that releases mediators of inflammation from epidermal cells
- Occurs within 1 – 24 hours; can occur within minutes
irritant contact dermatitis symptoms
Red rash with pain, burning, stinging, discomfort; maybe no itching
Often affects hands
Occupations: cleaning, hospital care, food prep, hairdressing
Soap and water, solvents, microtrauma, dry air, cleaners
irritant contact dermatitis diagnosis
Erythema- redness
Edema
Glazed, parched, scalded appearance
Skin usually dry with scaling
No diagnostic test
Patch test negative
Dx based on exclusion of other cutaneous diseases and clinical appearance of site exposed to a known irritant
irritant contact dermatitis tx
- Avoid irritant via barriers
- Non-sensitizing moisturizers
- -Plain petroleum jelly
- Mild skin cleansers
- -Aquanil, Cetaphil cleanser, Neutrogena cleanser
- Soaps with low irritant effect
- -Dove, Cetaphil
- Alcohol based hand cleansers with moisturizer
- Avoid inappropriate solvents or abrasives to clean hands
- No topical steroids!!!
Allergic Contact Dermatitis more tx
Occurs in sensitized individuals
Involves a cell mediated immunity response
Requires a latency period
The re-exposure precipitates the dermatitis
Response is usually in 48 hrs
Subjective
Hx is very important!
Red rash with ITCHING
possible allergens
Plants (poison oak*, ivy) Metals (nickel*, gold) Hair products Skin care products Rubber/latex Dyes Chromates for leather tanning Fragrances Preservatives Acrylates Cosmetics
Topical ocular drugs allergies
Antazoline Neomycin Phenylephrine Atropine Pilocarpine Anti-glc drugs
allergic contact dermatitis objective
-Pruritis ( = itch!)
-Erythema
-Edema
-Chemosis of conjunctiva
-Vesicles
Weeping rash –> crusting, scaling –> darkened, cracked (fissured), leathery appearance
Keratitis may develop
allergic contact dermatitis dx
patch test
-Elicited from history
- Patch skin tests
- -Application of suspected materials to skin on patches
- -Left on 48 hours, then read again between 72 hrs – 1 wk
- -Positive: development of erythema, papules, edema, vesicles
- -Correlation with history, location of eruption, clinical course to determine if true etiology
DDX from many similar appearing rashes
allergic contact TX/Management
Remove allergen
Cold compresses 4 – 6X/day
Topical steroid ung or cream BID – TID for 5 – 10 days
< 1% hydrocortisone
Oral antihistamine
Diphenhydramine (Benadryl)
Ocular lubricants 4 – 6X/day for comfort or keratitis
Topical immunomodulator BID
Pimecromlimus (Elidel cream)
Tacrolimus (Protopic)
ATOPIC DERMATITIS
Eczematous skin eruption AKA eczema
Onset in infancy: most common skin disease in children
Inherited condition
Usually in conjunction with other atopic conditions
INFLAMED PATCHES OF VERY ITCHY SKIN
atopical dermatitus Clinical manifestations
Lesions vary with age
Early infancy:
- Rash that is exudative, vesicular to maculopapular, see fine scales
- Location often on face (cheeks common), scalp, knees in infants
- ITCHING
Atopic Dermatitis later stages
Dermatitis
Skin becomes dry and lichenified
Excoriated areas (abraded)
Pruritus ITCHING
Healing - hypo or hyper-pigmentation
Location most often seen on elbows, neck, back of knees, ankles in adults
Atopic Dermatitis susceptibility
- Patient is more prone to secondary infection due to Staphylococcus or Streptococcus
- Unusual susceptibility to vaccinia, herpes simplex and molluscum contagiosum viruses
-Possible ocular manifestations of atopic dermatitis
Primarily lids
Clinical Course unpredictable, but usually subsides by age 3 or 4 with exacerbations and remissions frequently recurring throughout childhood, adolescence and adulthood
Atopic Dermatitis symptoms
ITCHY rash Erythema Edema Exudative lesions Xerosis Lichenfication Excoriation and crusting
atopical dermatitis dx
DX - tests not needed if condition presents with clear clinical markers
Patch test
Nonmedical considerations:
Clothing
Cool temperature
Humidifier
