Irritant and contact dermatitis Flashcards
What is irritant contact dermatitis (ICD)?
Localized, non-immunologically mediated cutaneous inflammatory reaction. Secondary to direct exposure to a topical external agent
ICD accounts for how much of contact dermatitis?
80%
Does ICD require previous exposure to agent?
No
How long does it take for ICD to occur?
Usually within a few minutes or hours
Describe acute phase of ICD
Erythema, edema and vesiculation followed by erosions and scaling
Describe chronic phase of ICD
Erythema, lichenification, fissures and scale
Areas commonly affected by ICD?
Hands (soaps, wet work, acids, solvents, alcohols, cleansers, food, plants, etc), lips (lip licking)
Describe pathology of ICD
Trauma from offensive physical or chemical agents creates cytotoxic epidermal damage, leading to a series of specific alterations to structure and function of skin –> lipids stripped –> TEWL –> activation of keritinoncytes and innate immune system –> release of proinflammatory cytokines –> activate t-cells –> Langerhans cells emerge –> increased inflammatory reaction
Differential for ICD?
ACD, dyshidrotic eczema, endogenous eczema, thermal burn
History questions for ICD
Occupation? Do sx improve with time off? Hobbies? What sort of materials handled? History of eczema as a child?
Treatment of ICD?
Avoidance of irritant, protective clothing and barriers, topical corticosteroids, good skin hygiene
What is allergic contact dermatitis (ACD)?
A localized, cutaneous delayed hypersensitivity inflammatory reaction.
What is the first symptom of ACD?
Pruritus during acute phase
Does patient need to be previously sensitized to agent in ACD?
Yes
Describe acute phase of ACD
Erythema, edema vesicobullae, weeping and pruritus
