There are three kinds of reactions. The first is contact dermatitis, redness and itching caused by direct contact with one or more chemical additives in latex or in the powder used to ease putting on gloves. With chemical sensitivity dermatitis, the lymphocytes of the immune system are activated. Skin contact with chemicals used in processing causes redness, itching and sometimes hives. Symptoms appear one to 48 hours after exposure, appearing sooner and lasting longer with repeated encounters.
True allergy is a response to latex proteins.
Mast cells release histamine, causing symptoms ranging from merely annoying redness, itchiness and hives, to general swelling, breathing difficulties, fast or irregular heartbeat, nausea, low blood pressure and possibly cardiopulmonary arrest. Reactions are often more severe with repeated exposure. In some cases this means moving the victim, since protein-bearing powder can remain in the air for five to 12 hours. People with known latex allergy often carry prescribed epinephrine kits for self-injection at the first sign of reaction. Some also keep non-latex gloves at hand for rescuers.