DERM 13: Contact Dermatitis

Question 1

What is allergic contact dermatitis?

Answer 1

• T-cell-mediated delayed hypersensitivity-type response (prior exposure/sensitization to allergen)
• reaction appears 24-48 hours after exposure

Question 2

What is irritant contact dermatitis?

Answer 2

• non-allergic response
• reaction may appear at first exposure

Question 3

What are the risk factors? (3)

Answer 3

• caucasian
• impaired cell-mediated immunity
• environmental factors – exposures to irritants, allergens (occupation, household)

Question 4

What are the presentation/symptoms of allergic contact dermatitis (acute)?

Answer 4

• intensely pruritic, painful (from scratching)
• range from mild erythema to severe bullae +/- ulceration

Question 5

What are the presentation/symptoms of irritant contact dermatitis (acute)?

Answer 5

• pain > pruritis
• range from mild erythema to crusting pustules, bullae, hemorrhage, and erosions

Question 6

What symptoms do atopic dermatitis and contact dermatitis share? (5)

Answer 6

• pruritus
• scratching
• erythema
• edema
• pain

Question 7

Compare the locations of atopic dermatitis and contact dermatitis.

Answer 7

• atopic: typical patterns
• contact: distinct (exposure)

Question 8

What are the symptoms of acute atopic dermatitis?

Answer 8

• xerosis
• blistering
• oozing
• crusting

Question 9

What are the symptoms of chronic atopic dermatitis?

Answer 9

• thickening
• lichenification
• discolouration

Question 10

When should a patient be referred? (3)

Answer 10

• > 20% BSA affected
• delicate areas (eyelids, genitalia) affected
• extreme clinical presentation (bullae, ulceration, erosions)

Question 11

What are the goals of therapy? (4)

Answer 11

• remove/modify underlying cause/exacerbants
• minimize morbidity – rash symptoms (pruritus, eruption size/number), complications (infection, repeated episodes)
• minimize adverse drug reactions
• optimize quality of life (patient-specific)

Question 12

What is the pharmacological treatment for contact dermatitis?

Answer 12

topical corticosteroids

• if persistent allergic contact dermatitis: topical calcineurin agents, systemic therapies (unknown causes may require patch testing)
• no topical antihistamines

Question 13

What are the monitoring points for effectiveness?

Answer 13

pruritis, erythema, eruption size, QOL
symptom

• improvement within 1 week
• complete resolution in 2 weeks