The primary objectives of this study are to identify positivity rates to three novel surfactants (ingredients used in soaps, detergents, and other cleansers that serve to lower the surface tension of the skin and remove debris) and co-reactivity with other surfactants in patients with known surfactant sensitivity on skin patch testing. The investigators hypothesize that subjects who previously tested positive to known allergenic surfactants (cocamidopropyl betaine, stearamidopropyl dimethylamine, dimethylaminopropylamine, coconut diethanolamide, oleamidopropyl dimethylamine, and decyl glucoside) may demonstrate co-reactivity to the three novel surfactant sensitizers (sodium lauroyl sarcosinate, isostearmidopropyl morpholine lactate, and disodium lauroamphodiacetate) on skin patch testing.

Inclusion Criteria:

1. Documentation of a previous contact allergy to one or more surfactant(s) on our screening series including:

   • cocamidopropyl betaine
   • stearamidopropyl dimethylamine
   • dimethylaminopropylamine
   • coconut diethanolamide
   • oleamidopropyl dimethylamine, and
   • decyl glucoside

2. Age 18 years or greater.

Exclusion Criteria:

1. Pregnant or lactating women
2. Use of systemic therapy (corticosteroid, immunosuppressive agents, cytostatics, pentoxifylline, leukotriene antagonists or other medication known or suspected to have an effect of ACD) within two weeks prior to participation
3. Use of intramuscular steroids in the last month.
4. Phototherapy (PUVA or UVB) within two weeks prior to participation.
5. Direct sunlight or tanning booth use to the back within the two weeks prior to participation.