Are hives or small raised bumps a symptom of contact dermatitis?

No, hives are due to a Type I hypersensitivity, which is a true adverse immunological reaction. This form of immediate allergic reaction is an IgE (reaginic)-based response, which means visible manifestations occur in response to specific antibodies and released pharmacological mediators (i.e. histamine, serotonin. prostaglandins, slow-reacting substance–anaphylaxis). A variety of substances can induce this type of reaction, ranging from house dust to foods to chemicals. The IgE-mediated allergic reaction can produce a wheal and flare skin lesion (i.e.hives), which usually develops within a few minutes after challenge exposure to the allergen. This is also one of the harmful allergic reactions which can also develop against certain natural rubber latex (NRL) proteins. As an example, you may wear latex gloves for 20 years and one day your body tolerance to the allergens disappears. You subsequently become sensitized to the few allergenic proteins in the latex liquid. Clinical symptoms can then develop with the next, and subsequent, challenge exposures. A more severe manifestation of  Type I hypersensitivity can develop in certain persons who are allergic to airborne allergens. Allergic challenges via respiratory or conjunctival tissues to NRL or allergens can lead to more systemic anaphylactic symptoms, such as coughing, wheezing, shortness of breath and/or respiratory distress.