Contact Allergy (Contact Dermatitis)
Although usually confined to the area of contact, in severe cases the inflammation can spread. Reactions can begin immediately or hours after contact, and lessen within days providing the skin is no longer in contact with the offending substance. Some of the most common contact allergies include nickel, poison ivy, and latex.
Contact dermatitis differs from hives (contact urticaria), in which a rash appears within minutes of exposure and fades away within minutes to hours. The allergic reaction to latex or nickel (in jewelry) are well known causes of hives.
Contact allergy usually occurs externally on the skin rather than from internal sources or food. The first contact does not necessarily result in allergy; often the person has been in contact with the material for years without any problems.
Identifying contact allergy is easily done with specific tests (skin or patch). The rash typically clears up if the allergen is no longer in contact with the skin, but can recur even with slight contact. Contact allergies can be treated with allergy drop therapy to decrease and eliminate sensitivities over time.
Sublingual Immunotherapy for Poison Ivy
Poison ivy dermatitis is the most common contact allergy in the U.S. affecting approximately half of the population according to the American Academy of Dermatology. Each year, 10 -15 million Americans develop an allergic reaction after contact with poison ivy.
While sublingual immunotherapy has been studied for multiple type I immune reactions, few have have been done for type IV delayed hypersensitivity reactions such as poison ivy.
For decades, we have treated patients who suffer from severe poison ivy dermatitis with sublingually administered poison ivy extract. We conducted a review* of 115 patients and evaluated symptom improvement as well as repeated skin test results. Clinically, 90% of patients reported fewer episodes of poison ivy. Those who still have episodes stated it was markedly less severe and shorter in duration. Skin testing results showed an average increase in concentration of antigen required to cause a reaction increased by 125 times.
* Study results presented at the 2007 American College of Allergy, Asthma & Immunology annual meeting.