Topical glutaraldehyde-percutaneous penetration and skin irritation.

To investigate the safety of the topical application of glutaraldehyde to the ankle and heel of man, the in vitro penetration of glutaraldehyde in a 10% aqueous solution through isolated human thin stratum corneum (chest and abdomen), isolated human epidermis (abdominal), and human thick stratum corneum (blister tops from the sole) was determined 1 h after application. Under these conditions, glutaraldehyde did not penetrate thick stratum corneum, while 2.8%-4.4% of the applied dose penetrated the isolated epidermis, and 3.3%-13.8% of the applied dose penetrated thin stratum corneum. An 8-week irritancy test was conducted by applying a 10% aqueous solution of glutaraldehyde to the ankle and heel area of 12 volunteers. Irritation and one case of sensitization resulted from glutaraldehyde application to areas of thin stratum corneum (anterior ankle) but not from applications to thick stratum corneum (medial, posterior, and lateral heel and posterior ankle), which may be a privileged site with respect to glutaraldehyde sensitivity.

Allergic contact hypersensitivity to nickel, neomycin, ethylenediamine, and benzocaine. Relationships between age, sex, history of exposure, and reactivity to standard patch tests and use tests in a general population.

A study population of 1,158 paid adult volunteers was obtained. Prior to patch testing, a history of previous exposure to four allergens also was obtained. Prevalence of positive reactions to patch tests was nickel, 5.8%; neomycin, 1.1%; ethylenediamine, 0.43%; and benzocaine, 0.17%. Nine percent of women reacted to nickel compared with 0.9% of men. There was a strong correlation of nickel sensitivity with a history of pierced ears, earlobe rash, and jewelry rash. Ten of 12 neomycin-positive subjects used neomycin for one week or longer on an inflammatory dermatosis, compared with six of 36 age-, race-, and sex-matched controls. By history, 85% were exposed to benzocaine, 48% to neomycin, and 15% to Mycolog (ethylenediamine). Of 127 patients referred to clinics for evaluation of contact dermatitis, 11% yielded positive tests to nickel, 6.3% to neomycin, 3.1% to ethylenediamine, and 1.6% to benzocaine. Data obtained from testing contact dermatitis patients are not applicable to the general population.

Allergic hypersensitivity to neomycin. Relationship between patch test reactions and 'use' tests.

The prevalence of neomycin patch test sensitivity in the general population is approximately 1%. We describe the relationship between positive neomycin patch tests and clinical "use tests" with two antibiotic combinations (Neosporin G cream and Neosporin ointment). The neomycin use test was positive in seven of eight subjects with a strongly positive patch test, and in two of four subjects with a weakly positive patch test. A positive use test usually occurred earlier and was always more intense with the cream base. The use test reactions were usually mild even with continued application of the antigen. Use tests with commercial products may be helpful in evaluating the clinical relevance of positive patch tests.