Case 4 - Irritant Contact Dermatitis PWQ

Question 1

Describe the aetiology and pathophysiology of contact dermatitis

Answer 1

Contact dermatitis (also called contact eczema) refers to a group of skin disorders in which the skin reaction is due to direct contact with the causative agent.

Contact dermatitis begins with the skin coming into contact with the allergen. The allergen then penetrates the stratum corneum of the skin and is taken up by Langerhans cells. As a result, many processes eventually lead to antigen-specific T lymphocytes migrate to the epidermis, causing an inflammatory response.

Question 2

Discuss the differences between atopic eczema and contact eczema

Answer 2

Both are forms of eczema and have the same symptoms but different causes. Atopic eczema is usually inherited whereas contact eczema results from coming into contact with an external factor.

Question 3

Discuss the differences between irritant and allergic contact dermatitis

Answer 3

Irritant contact dermatitis is caused by exposure to (multiple) irritants. The likelihood of contracting this condition is dependent on the potency of the irritant and the anatomical site. Severity is determined by the level of impairment of the skin barrier function.

Allergic contact dermatitis is caused by exposure to allergens which can take years of uneventful exposure before symptoms arise. This type of dermatitis only requires minimal exposure to induce effects.

Question 4

State 4 pharmacological and 2 non-pharmacological treatment options for contact dermatitis

Answer 4

Pharmacological:

• Emollients
• Barrier creams
• Topical steroids
• Calcineurin inhibitors

Non-pharmacological:

• Wear gloves
• Phototherapy

Question 5

Explain the function of barrier creams, with reference to the different types of barrier creams

Answer 5

Barrier creams are products applied directly to the skin to help maintain the skin’s physical barrier, providing protection from irritants and preventing the skin from drying out.

Conventional barrier creams contain occlusives and humectants and help maintain water to keep skin hydrated.

Novel barrier creams contain vitamin B3 or ceramides that promote healing of the skin barrier.