Contact dermatitis, particularly facial contact dermatitis is a very frustrating problem to deal with for both the patient and the Allergist because of the natural history timeline for onset and resolution. Contact dermatitis is a type of T-cell mediated delayed-type hypersensitivity to small chemicals that can bind to skin proteins. There is typically a two to five-day lag between exposure and onset of the rash. If no new exposure to the contact irritant chemical(s), then the contact dermatitis rash will clear on their own in two to six weeks as new skin grows out that does not have the chemical bound to skin proteins. The North American Patch tray only identifies a minority of the contact dermatitis cases. Basically, there are three options:
1) No makeup
2) Custom patches with all new make-up products prior to facial application.
3) A slow trial and error process. When the rash is completely clear, off all medications, then OK to use any 1 new material in any 1 week. If the rash returns, then stop the last material restarted. Expect another two to six weeks of active rash. Repeat process as needed.
I hope this information is of help to you and your patient.
Eric Macy, MD, MS, FAAAAI