Editor, Assessment of a possible drug reaction after dental therapy requires consideration of the type and timing of the reaction, the circumstances under which it occurred and confirmatory testing where possible ('Dental implications' Aust Prescr 1994;17:65). Delayed reactions such as 'burning mouth syndrome', palatal and gingival swelling, perioral dermatitis and recurrent apthous ulceration are well described, and have been attributed to 'Type IV' responses to heavy metals, methacrylate resins and other substances used in amalgams, cements, plates, dental instruments and even mouthwashes.1 Of greater concern are immediate (Type I) allergic responses, resulting in local or systemic reactions. Investigation of patients has previously concentrated on excluding allergic responses to anaesthetic agents or additives and hereditary angioneuroticoedema. The increased use of gloves in medical and dental practice has added another potential allergen to consider: latex. Latex allergy is IgE mediated and, unlike rubber induced dermatitis (a delayed Type IV reaction), may rapidly precipitate local or generalised urticaria, or even anaphylaxis.2 Conjunctival irritation, nasal congestion and bronchospasm may occur, mediated by airbornelatex allergen bound to glove-derived dry powder lubricants.3 Risk factors include a topic status, multiple previous exposures to latex (occupational, as a patient) or previous reactions including glove-related hand dermatitis.2 Confirmatory testing is yet to be standardised; skin testing with 'home-made' latex extracts carries a significant risk of inducing anaphylaxis. 'Hypoallergenic' gloves may still contain allergens; the best prevention is the pretreatment dental or medical history, and use of non-latex products where indicated.4
Raymond J. Mullins
Clinical Immunologist
Newtown, N.S.W.
