Patch testing with neomycin sulfate

Abstract

The recommended patch test concentration of neomycin sulfate is 20% in petrolatum applied occluded for 48 h (2 days [D]). In the current study, the efficiency of such a test is compared to results with other techniques using lower allergen dose than obtained by approximately 20 microl of the 20% substance. Efficiency of petrolatum and demineralized water as vehicles are compared. 16 neomycin-sulfate positive subjects were retested with serial doses ranging from 0.4 to 0.0085 mg/cm2 neomycin sulfate in cellulose printed on polyester squares and applied by both tapes and plastic foils. Additionally, tests were performed with the 20% petrolatum substance in Finn Chambers. Tests containing the 20% substance in petrolatum and in water were applied directly with transparent foils. Readings ranged from 3 to 264 h (11D) following applications. Results show that foil applications of a polyester square dose, that is 7% of the dose obtained with the 20% substance, distinguished between perfusion of subjects who were visually positive and not with any test in the study. With the same test technique and visual assessments, 2 subjects were false-negative but developed doubtful test responses with the Finn Chambers.

Patch test results of the European baseline series among 1309 patients in Turkey between 2013 and 2019

“…Although it was once one of the most important allergens, sensitivity prevalences have decreased in recent years. [40][41][42] Our results indicate that, in parallel with the decrease of sensitivity in Europe and North America, neomycin sensitivity has also been decreasing in Turkey (1.2% in 2013-2019 vs 2.4% in 1998-2005). This decreasing trend was most likely influenced by increased use of topical antibiotics containing fusidic acid or mupirocin.…”

Allergic Dermatitis Due to Topical Antibiotics

“…In 2007, the North American Contact Dermatitis Group performed a cross-sectional analysis of over 950 patients suffering from allergic contact dermatitis of the hand and found neomycin sulfate as well as bacitracin to be 2 of the top 12 causes of hand dermatitis (7.7% and 7.4% of all hand cases, respectively). 2 Sensitization to neomycin may be associated with vehicle type 3 and duration of use. 4,5 Furthermore, simultaneous contact allergy to all 3 ingredients of triple antibiotic ointment has been reported in the literature.…”

Decreasing Rates of Neomycin Sensitization in Western Canada

“…1 Given its wide use, it is not surprising that neomycin is among the most frequently reported allergens that generate positive patch test responses. 2…”