Synopsis
Separate cumulative irritant barrier injury from delayed allergic contact dermatitis, identify occupational exposures, use patch testing appropriately, and build feasible avoidance and treatment plans.
- Irritant dermatitis reflects exposure dose and barrier damage; allergic contact dermatitis is delayed type IV hypersensitivity requiring previous sensitisation.
- Wet work means repeated hand wetting or prolonged glove occlusion as well as obvious chemical exposure; atopic skin lowers the irritant threshold.
- Allergic dermatitis can spread beyond the exact contact border, while irritant disease often affects the most exposed surfaces, but morphology alone is not definitive.
Key red flags
Eye involvement, deep chemical injury, widespread bullae, fever, rapidly progressive pain, occupational inability to avoid exposure or persistent facial and hand disease requires urgent or specialist assessment.
Wheals, respiratory symptoms or collapse within minutes suggests contact urticaria or anaphylaxis and requires an immediate-allergy pathway.
Investigation priorities
Identify irritant dose, plausible sensitiser and opportunities for substitution.
Management branches
Exposure is frequent and dose-related, patchy on contact surfaces and lacks a specific delayed allergen pattern.
- Substitute soap and harsh cleanser with a suitable emollient wash, reduce wet-work duration and use task-specific gloves with cotton liners when prolonged wear is unavoidable.
- Apply leave-on emollient repeatedly and a site-appropriate topical corticosteroid to active inflammation for a defined course.
Key medicines
Hydrocortisone 1% creamAdults apply thinly once or twice daily for no more than seven days under this licence, with site-specific clinician review if further treatment is needed.
Betamethasone valerate 0.1% creamApply a thin layer once or twice daily to affected trunk, limb or hand skin for up to four weeks, then reduce or stop with control.