Latex-Induced Occupational Asthma

Latex induced occupational asthma is asthma caused by IgE-mediated sensitisation to natural rubber latex proteins inhaled at work. The allergen is usually carried on glove powder or released from latex products.

Exposure. Healthcare and dental staff, laboratory workers, cleaners, food handlers, hairdressers, and glove and balloon manufacture. Intensity of powdered glove use is the main driver.

Epidemiology. Sensitisation affected roughly 5 to 10% of exposed healthcare workers in older series. Rates fell after powder free, low protein gloves replaced powdered ones.

Risk factors. Atopy, hand dermatitis (broken skin barrier), high glove use and prior latex contact urticaria.

Spectrum. Contact urticaria, rhinoconjunctivitis, asthma and anaphylaxis can occur in the same person. Some patients also react to banana, avocado, kiwi and chestnut (latex fruit syndrome).

Pathophysiology.

Hevea brasiliensis proteins bind powder particles and are aerosolised when gloves are donned or removed. Inhaled allergen cross-links specific IgE on airway mast cells and causes early phase bronchoconstriction.

A late phase eosinophilic response sustains airway inflammation and hyperresponsiveness. Cross-reactive plant proteins explain the fruit associations.

• Cough, wheeze, chest tightness and dyspnoea, often minutes after glove changes or in theatre or clinic areas, improving away from work.
• Rhinitis, conjunctivitis and hand urticaria commonly coexist.
• Oral itching or swelling after eating cross-reactive fruit.

Red flags.

• Stridor, facial or tongue swelling, hypotension or collapse (anaphylaxis).
• Severe attacks during surgery or procedures.

• Detailed work history with glove types, powder use and co-worker symptoms.
• Spirometry with reversibility of 12% and 200 mL, or methacholine challenge (PC20 under 8 mg/mL suggests asthma).
• Serial peak flow at least 4 times daily over at least 2 weeks at work and 2 weeks away, analysed by a validated method.
• Serum specific IgE to latex: sensitivity roughly 75 to 90%, with lower specificity. Component testing helps separate true sensitisation from cross-reactivity.
• Skin prick testing with a licensed extract where available, in a unit able to treat anaphylaxis.
• Specific inhalation challenge in a specialist centre is the reference test, with a fall in FEV1 of 20% or more being positive.

Differential diagnosis. Work exacerbated asthma, irritant induced asthma from powder or disinfectants, other occupational asthma, allergic contact dermatitis, irritant rhinitis, vocal cord dysfunction.

• Remove from latex exposure. In shared workplaces this means eliminating powdered latex gloves and providing nitrile or other non-latex gloves for all staff in the area.
• Confirmed sensitisation: continued latex exposure risks severe asthma and anaphylaxis. Counsel on medical alert identification.
• Budesonide with formoterol 200/6 micrograms inhaled, 1 inhalation twice daily as maintenance plus 1 inhalation as needed (adults and adolescents 12 and over). Usual maximum 8 inhalations in 24 hours, up to 12 for a short period. Monitor symptoms, spirometry, exacerbations and oral candidiasis; rinse mouth after use. No renal adjustment; step up or down by control.
• Exacerbation: salbutamol 100 microgram metered dose through a spacer, 4 to 10 puffs, repeated every 20 minutes for the first hour, then every 4 hours as needed. Maximum 10 puffs each dose. Monitor heart rate, potassium and oxygen saturation. Caution in arrhythmia and hyperthyroidism.
• Exacerbation: prednisolone 40 to 50 mg orally once daily for 5 days, with no taper. Maximum 50 mg daily. Monitor glucose and blood pressure. Caution in diabetes and peptic ulcer; acceptable in pregnancy when needed; no renal adjustment.
• Anaphylaxis: adrenaline 500 micrograms (0.5 mL of 1 mg/mL) intramuscularly into the anterolateral thigh, repeated after 5 minutes if there is no improvement. No fixed maximum; titrate to response. Monitor airway, blood pressure, heart rate, ECG and oxygen saturation. Children: 10 micrograms/kg, maximum 500 micrograms. Do not withhold in coronary disease. Prescribe an adrenaline auto injector (adults 300 micrograms) for confirmed sensitisation with systemic reactions, with training.

Monitoring. Review every 3 months initially with spirometry and control assessment; serial peak flow if any exposure continues.

Referral and escalation. Respiratory and occupational physician; allergist for systemic reactions; workplace assessment; urgent care for severe attacks or anaphylaxis; notification and compensation where required.

Special groups. Pregnancy: continue inhaled corticosteroid and avoid exposure. Patients needing frequent surgery should have latex free theatre arranged in advance.