Latex Contact Urticaria

Latex contact urticaria is an immediate type I hypersensitivity reaction of the skin to natural rubber latex proteins, with itching and wheals within minutes of contact. It can progress to rhinoconjunctivitis, asthma and anaphylaxis.

Exposure. Healthcare, dental and laboratory staff, food handlers, hairdressers, cleaners, and manufacturing of gloves, balloons and rubber products. Airborne latex on glove powder carries allergen.

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

Risk factors. Atopy, hand eczema, repeated glove use and previous surgery, especially in spina bifida and urological disease.

Contact urticaria syndrome stages. Stage 1: localised urticaria or dermatitis. Stage 2: generalised urticaria. Stage 3: rhinitis, conjunctivitis or asthma. Stage 4: anaphylaxis.

Latex fruit syndrome. Cross-reactions occur with banana, avocado, kiwi and chestnut.

Pathophysiology.

Latex proteins such as Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 cross-link specific IgE on mast cells. This releases histamine and other mediators and produces wheals and itching.

Cross-reactive plant proteins and an impaired skin barrier amplify sensitisation.

• Itching, redness and wheals on contact areas within 5 to 30 minutes of wearing latex gloves, settling within hours of removal.
• Hand eczema that worsens with gloves.
• Associated rhinitis, conjunctivitis, wheeze and oral itching after eating cross-reactive foods.
• Generalised urticaria, angioedema and collapse in severe reactions.

Red flags.

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

• Detailed history of glove use, latex products, timing of reactions and cross-reactive foods.
• Specific IgE to latex: sensitivity about 75 to 90%, with lower specificity; component testing separates true sensitisation from cross-reactivity.
• Skin prick test with a licensed extract where available, in a unit equipped to treat anaphylaxis.
• Glove use test with a latex finger, or provocation test in a specialist centre, when results are uncertain.
• Lung function and rhinitis review if respiratory symptoms.

Differential diagnosis. Rubber chemical allergy (delayed type IV), irritant contact dermatitis, atopic eczema, urticaria from other causes, food allergy, cold or pressure urticaria.

• Remove latex from the exposure: powder free nitrile or other non-latex gloves for the patient and for those working nearby, and a latex free environment for procedures.
• Counsel on cross-reactive foods and on medical alert identification.
• 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.
• 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.
• Hand eczema from gloves: emollient applied liberally at least twice daily and after each handwash, long term.

Monitoring. Review at 4 to 6 weeks, then every 6 to 12 months; update auto injectors before expiry.

Referral and escalation. Allergist for systemic or respiratory features; occupational physician for latex free workplace; emergency care for anaphylaxis; notification and compensation where required.

Special groups. Pregnancy: adrenaline is used for anaphylaxis. Children with spina bifida need a latex free environment from birth.