Ch. 34 Contact Dermatitis Flashcards
1
Q
Contact Dermatitis
A
- Inflammation, redness, itching, stinging, vesicle/pustule formation
- Occurs due to exposure from an irritant or antigenic
- Types: Irritant Contact Dermatitis (ICD) or Allergic Contact Dermatitis (ACD)
- Differ by etiology and presentation
2
Q
ICD
A
- Common when working in personal services or health care
- Those who must wash hands frequently, handle foods, or are repeatedly in contact with irritants are at an increased risk
- Usually occur on exposed skin surfaces like hands, face, arms, and can occur at first exposure or after multiple exposures
- Mechanisms: disrupts skin barrier, changes epidermal cells, and released of proinflammatory cytokines
- Quantity, concentration, tight clothing, diapers, humidity, warm climates, and other skin conditions can increase its severity
- Chemical irritants, acids, and alkalis can have immediate, severe reactions
- Mild irritants like detergents, soaps, and solvents tend to cause reactions after repeat exposures
3
Q
ICD Clinical Presentation
A
- Skin becomes inflamed, swollen, and turns erythematous with irritant exposure
- Often a delayed reaction
- Primarily dry/macerated, painful, cracked, inflamed skin
- Itching, stinging, burning are also common
- Inflammation can range from slight swelling to ulcers to local necrosis
- Resolves when irritant is avoided but can take several days
- IF chronically exposed, may develop fissures, scales, lichenification, leathering/thickening of skin, and hypo or hyperpigmented skin; some resolve completely
4
Q
ICD Treatment Goals
A
- Remove offending agent and prevent exposure
- Relieve inflammation, dermal tenderness, and irritation
- Educate patient on self-management to prevent or treat recurrences
5
Q
ICD General Treatment
A
- Avoid irritant
- Preventative measures
- Patient education
6
Q
ICD Nonpharmacologic
A
- Wash area of exposure with lots of tepid water and mild or hypoallergenic soap
- Will decrease contact times with irritant and decrease the reaction or lessen the symptoms
7
Q
ICD Preventative Measures
A
- Educating in techniques to reduce exposure
- Protective clothing, gloves, other equipment, and limiting time skin is occluded by changing coverings often to decrease exposure
- Emollients, moisturizers, and barrier creams (esp. dimethicone) are recommended to treat and prevent ICD since they repair epidermal barrier
8
Q
ICD Pharmacologic
A
- Liberal applications of emollients help moisturize stratum corneum and protect from further exposure
- Colloidal oatmeal baths can relive itching
- Topical corticoids have questionable efficacy and are not recommended
- Topical “caine” anesthetics should be avoided since they can cause ACD
9
Q
ACD
A
- Poison ivy, oak, or sumae = common ACD inducers
- Metal allergy, particularly to nickel is also very common (19%)
- Latex is also a common reaction in health care workers
- Fragrances, cosmetics, and skin care can also cause ACD
10
Q
ACD Pathophysiology
A
- Inflammatory dermal reaction activates sensitized T cells which go to the site of contact and release inflammatory mediators
- Doesn’t occur on first contact usually
- Initial exposure sensitizes immune system (induction)
- Next exposure induces type IV allergic reactions where cell mediated reaction occurs, can take 24 hours to 21 days to develop (dermatitis symptoms)
- Rash/symptoms usually occur in 24-48 hours
11
Q
Urushiol-Induced ACD
A
- 4 species of Toxicodendron plants - primary dermatoses causers in plants
- 80% of population may be sensitive to urushiol
- Enters skin in about 10 minutes and starts sensitivity process
- Poison ivy/oak/sumac reactions are reported in as young as 3 year olds, increased incidence in adulthood and drops back down in the elderly
- Usually allergic to all plants if allergic to one
- “Leaves of three, leave them be” (more consistent with ivy)
- Produce small, waxy, white, five-petaled flowers in spring and green/white/pale yellow berries in fall
- Urushiol is sensitive to oxidation and changes from clear fluid to a black, inky, tar like substance
- Only released from plant damage, usually contained
- Not volatile, but can still cause dermatitis from smoke exposure if burned
- Unwashed, contaminated hands can also transfer urushiol to other parts of body, causing reaction
12
Q
Poison Ivy
A
- Most common Toxicodendron plant in the U.S.
- Climbing shrub or hairy vine that grows up poles, tress, and walls
- Radicans - shrub or vine, main type, throughout U.S.
- Rydbergil - dwarf shrub with large spoon-like leaves, 2nd main type and found in northern U.S.
13
Q
Poison Oak
A
- Two species indigenous in U.S.: diversilobum (West Coast) and toxicarium (East Coast)
- Both leaves are similar to oak tress, 3 leaves per stem, unlobed leaves
- Leaves and berries are covered in fine hairs
- Usually a non-climbing shrub but can climb up to 13 ft
- Western poison oak: 3-11 leaflets/stem, similar to California oak leaves
- Better at altitudes <4000-5000 ft
14
Q
Poison Sumac
A
- Vernix, grows in remote areas in eastern third of U.S., usually in bogs and swamps
- Usually a shrub or small tree, can grow ~9.8 ft
- May resemble elder or ash trees
- Leaves: odd numbered, pinnate, ~16” long potentially, with 7-13 leaflets/stem
- Leaves are smooth and come to a tip
15
Q
ACD Clinical Presentation
A
- Distribution and presentation of rash is the main difference
- Both occur where irritant touched, but ICD usually only on hands are arms from occupational exposure
- ACD usually limited to areas contacted by antigen, but can spread to broader areas of body form transferring contaminant from the hands to objects/self
- ACD: papules, small vesicles, significant itching, large bullae over inflamed, swollen skin sometimes too
- Chronic presentation: lichenification
