To study the incidence of contact hypersensitivity to commonly used topical antibacterials

摘要

Use of topical antibacterial therapy forms anchor sheet of treatment in dermatology but chances of developing problems with the use of this therapy cannot be ignored. 300 individuals attending Dermatology OPD were patch tested for 13 topical antibacterials brands by using 3900 indigenously designed Finn chamber discs. Sensitivities were recorded after 48 & 96 hours. 83/3900(2.13%) patches in 53/300(17.67%) individuals tested positive. Incidence of reactivity was seen in the descending order as: Neosporin (16.67%)à Soframycin (3.33%)àFuracin (3.33%)àEnsamycin (3.33%)àSilversulfadiazine (2%)àEryacne (2%)àMetronidazole (2%)àDettol (1.33%)àBetadine(1.0%)àClindacA gel(0.67%)àMupirax ointment(0.33%)àFucidin ointment(0%). Majority of cases i.e. 32/53(60.38%) tested positive to only one antibacterial,15/53(28.30%) cases showed sensitivity to two antibacterials, 4/53(7.55%) cases showed sensitivity to three antibacterials and 1/53(1.89%) case each showed sensitivity to four & five topical antibacterials respectively. Cross sensitivity was also observed among Neosporin, Soframycin & Ensamycin. Indigenously designed Finn chamber used in this study proved to be handy , time saving, economical & ideal. Neosporin(Neomycin) was the commonest sensitiser while Fucidin (Fusidic acid) & Mupirax (Mupirocin)were least sensitizing. The last two antibacterials can be safely recommended for topical usage. Introduction Topical antibacterials find a wider use in different specialties like medicine, dermatology, ophthalmology and surgery. They can be both antibiotics & antiseptics. Topically used medicaments contribute 14-40% cases of allergic contact dermatitis.1 The incidence of contact allergy to a medicament may also be an indicator of degree of usage of that particular topical antibacterial in a given community. In India, Nitrofurazone & Neomycin are the most common sensitizers.2 Contact dermatitis should be considered if there is insidious aggravation of pre existing dermatosis or the skin lesions stop showing any improvement.Contact dermatitis to the offending drug can be established by two methods—avoiding the suspected medicament for some period and then re-exposing to the same drug or by patch testing technique. The later provides an accurate, scientific, time preventing results which are very well applicable in vivo.3 This technique also helps us to discover latent hypersensitivity in a given population and the knowledge gained can be made use in appropriate selection of the topical antibacterials in better patient management.2 Aims & Objectives The present study envisaged to find out the incidence of contact and cross sensitization to topically used common antibacterials. Material & Methods 300 cases attending Dermatology OPD in a tertiary care hospital of Government Medical College, Amritsar (India) were randomly selected & patch tested with 13 commercially available commonly used antibacterials.It was ensured that none of these patients selected were suffering from any allergic disorder/generalized eczema / urticaria or taking antihistaminics and/or steroids. In case of patients forthcoming with history of usage of antibacterials, reason of usage & any local or systemic reaction with its use was also recorded.Patch test unitPatch test units including original unit of Jadassohn, Al-test, and Finn-chamber have been used. These units are expensive & have drawbacks.An ideal patch test unit is the one which should be handy and where smallest amount of possible test material can be used with minimum skin irritation. The test reaction should be localized to limited area of skin and above all should be economical. All these characteristics were kept in mind in designing an indigenously modified Finn chamber. This modified version of Finn Chamber was made out of indigenously available wastes consisting of aluminium discs 7 mm in diameter with 1mm elevated edges. These aluminium discs were obtained from the tops of empty injection vials used in hosp