Contact Dermatitis

Question 1

What is contact dermatitis?

Answer 1

An inflammatory skin condition which results due to exposure to an external irritant or allergen

Question 2

What are the 2 types of contact dermatitis?

Answer 2

Allergic - type IV delayed hypersensitivity reaction that occurs after sensitization and subsequent re-exposure to a specific allergen
Irritant - Non-immunological inflammatory reaction caused the direct physical/toxic effects of an irritating substance on the skin

Question 3

What are examples of common allergens?

Answer 3

• Personal care products such as cosmetics, skin care, nail varnish, sun screen
• Metals such as nickel/cobalt (jewellery)
• Topical meds such as corticosteroids

Question 4

What are examples of common irritants?

Answer 4

• Water
• Detergents, soaps and cleaning agents
• Acids and alkalis
• Powders, dust and soil

Question 5

What are risk factors for contact dermatitis?

Answer 5

• Occupations including florists, hairdressers, beauticians, cooks and metal workers

Question 6

How does irritant contact dermatitis present?

Answer 6

• Can be immediate or after repeated exposure
• Stinging, burning, dryness, chapping of the skin usually in the area in contact with the irritant

Question 7

How does allergic contact dermatitis present?

Answer 7

• Usually 24-72 hours after exposure
• Itching, blistering and weeping may be present

Question 8

What is the gold standard investigation for CD?

Answer 8

• Patch testing -> only indicated if chronic/persistent dermatitis which requires referral to dermatology

Question 9

How should contact dermatitis be managed?

Answer 9

• Avoidance of the stimulus for 8-12 weeks
• Liberal use of emollients and soap substitutes on the skin
• Consider topical corticosteroids if severe
• Advise patients to discuss with employer if exposure cannot be avoided
• Referral to dermatology if severe, recurring or not being well controlled