Fibreglass Dermatitis

Fibreglass dermatitis is an irritant dermatitis caused by mechanical penetration of the skin by glass fibres. It produces intense itching with a papular eruption and is not an allergy.

Exposure. Installing insulation, boat and vehicle building, composite and laminate work, electrical and textile manufacturing, and handling or laundering fibreglass materials.

Epidemiology. Common among new workers and during installation tasks. Symptoms often lessen as the skin adapts over days to weeks.

Fibre size. Fibres thicker than about 4.5 micrometres in diameter are the usual cause. Finer fibres are less irritating.

Associated illness. Eye, nose and throat irritation from airborne fibres, and allergic contact dermatitis to resin binders such as epoxy and phenol formaldehyde.

Pathophysiology.

Rigid fibre ends pierce the stratum corneum and stimulate nerve endings, causing itching and a follicular papular response. Scratching causes excoriation.

Friction from clothing drives fibres deeper. Resin binders can sensitise in a minority.

• Intense itching soon after exposure, with fine erythematous papules and follicular papules.
• Distribution on forearms, hands, neck, face, thighs and areas of clothing friction.
• Linear scratch marks and excoriations; no burrows.
• Transient eye, nose and throat irritation.

Red flags.

• Persistent unilateral eye pain or visual change (corneal foreign body).
• Spreading redness, pus or fever (secondary infection).

• Exposure history, timing of itch and effect of time off work.
• Adhesive tape stripping of affected skin with microscopy, showing glass rods or fragments.
• Examination for burrows to exclude scabies, with skin scrapings if doubt.
• Patch testing for resin allergy when eczema persists after fibre control.
• Eye examination with fluorescein when eye symptoms occur.

Differential diagnosis. Scabies, allergic contact dermatitis to epoxy or other binders, other irritant dermatitis, atopic eczema, urticaria, insect bites, grain itch.

• Reduce exposure: enclosed processes, local exhaust ventilation, wet cutting, and coated or low dust materials.
• Protective clothing: loose, tightly woven long sleeved overalls with taped cuffs, gloves and eye protection; wash work clothes separately.
• Rinse with cool running water and a soft cloth without rubbing; remove visible fibres with adhesive tape; avoid hot water at first.
• Cetirizine 10 mg orally once daily (at night if drowsy), increased to 20 mg daily if needed, while symptoms last. Maximum 20 mg daily. Monitor sedation. When eGFR is 10 to 30 give 5 mg daily and avoid when under 10; give 5 mg daily in hepatic impairment. Usual practice allows use in pregnancy when needed.
• Hydrocortisone 1% cream topically once or twice daily for up to 7 days to itchy inflamed areas, not to exceed 2 weeks on the face. Monitor for atrophy and periorificial dermatitis.
• Emollient applied liberally at least twice daily, long term.

Monitoring. Review at 2 to 4 weeks; reassess if the rash persists beyond 4 weeks despite exposure control.

Referral and escalation. Occupational physician for exposure control; dermatology if persistent or when resin allergy is suspected; ophthalmology for eye injury; notification and compensation where required.

Special groups. Pregnancy: use the lowest steroid potency and avoid prolonged use.