Airborne Occupational Contact Dermatitis

Airborne occupational contact dermatitis is irritant or allergic dermatitis from dusts, vapours, mists or sprays that settle on exposed skin, with a distribution that mimics photodermatitis.

Causes. Epoxy resin and amine hardeners, acrylates, isothiazolinone biocides in paints, formaldehyde, colophony, pesticides, cement dust, fibreglass, wood dusts, metalworking fluid mist, and plant allergens such as sesquiterpene lactones from Compositae plants.

Exposure. Painters, construction and joinery workers, farmers and gardeners, florists, laboratory and chemical workers, and workers in resin and composite manufacture.

Epidemiology. Underdiagnosed because it is often attributed to sun exposure or atopic eczema. It becomes chronic when exposure continues.

Distinguishing features. Involvement of the upper eyelids, behind the ears and under the chin favours airborne contact dermatitis over photodermatitis.

Pathophysiology.

Small particles and vapours deposit on exposed skin and mucosa, and haptens penetrate the barrier to cause type IV hypersensitivity in allergic disease. Irritant disease arises from direct cytotoxicity.

Chronic exposure drives persistent inflammation with lichenification. Some patients develop chronic actinic dermatitis in addition.

• Erythema, scaling and itch of the face, eyelids, neck (including the V area), forearms and dorsal hands.
• Eyelid oedema, conjunctivitis and rhinitis.
• Chronic lichenified plaques in persistent disease.

Red flags.

• Erythroderma or rapid spread.
• Weeping, crusting or fever (secondary infection or eczema herpeticum).
• Eye pain or visual change.

• Detailed work history: tasks, products, dust and mist sources, ventilation and effect of time away.
• Patch testing with a baseline series and occupational allergens, including the workplace's own samples at specialist directed concentrations; read at day 2 and day 4 or later.
• Photo patch testing and minimal erythema dose testing to exclude chronic actinic dermatitis.
• Swabs and virology when infection is suspected.

Differential diagnosis. Photoallergic and phototoxic dermatitis, chronic actinic dermatitis, atopic eczema, seborrhoeic dermatitis, rosacea, cosmetic dermatitis, airborne irritant dermatitis, lupus erythematosus.

• Avoid the culprit: enclose processes, local exhaust ventilation, wet methods, closed spraying, and substitution of allergens.
• Personal protection: face shield or full face respirator with eye protection, long sleeves, gloves, and washing of exposed skin after the shift.
• Emollient applied liberally at least twice daily, long term.
• Eyelids and face: hydrocortisone 1% cream topically once or twice daily for up to 7 days. Maximum 2 weeks on the face. Monitor for atrophy, periorificial dermatitis and, with periocular use, glaucoma or cataract.
• Tacrolimus 0.1% ointment topically twice daily to affected facial and eyelid skin for up to 6 weeks, then once daily until clear. There is no fixed maximum; apply a thin layer to the smallest area needed. Monitor burning, herpes simplex infection and skin cancer risk; avoid occlusion and sun exposure; avoid in under 2 years and in the immunocompromised; no renal or hepatic adjustment; use in pregnancy only if benefit outweighs risk.
• Body disease: clobetasol propionate 0.05% ointment topically once or twice daily for up to 2 weeks. Maximum 50 g weekly. Monitor skin atrophy, striae and infection. Avoid on the face, flexures and genitals and on infected skin.
• Severe acute flare: prednisolone 40 mg orally once daily in the morning for 5 days, then 20 mg for 5 days, then 10 mg for 5 days, then stop. Maximum 40 mg daily. Monitor glucose, blood pressure and mood. Caution in diabetes, peptic ulcer and infection; acceptable in pregnancy when needed; no renal adjustment.
• Persistent disease: change of job or process is often needed.

Monitoring. Review at 2 to 4 weeks, then every 3 months; reassess workplace controls.

Referral and escalation. Dermatology for patch testing and refractory disease; occupational physician for workplace change; ophthalmology for eye involvement; notification and compensation where required.

Special groups. Pregnancy: avoid prolonged potent steroid use over large areas. Children: use the lowest potency steroid.