Allergies are diagnosed in part by the symptoms that develop and the timing of their onset. Identifying an allergen can be a complex process when rashes are involved, because they may or may not be accompanied by other allergy symptoms. Whatever the trigger or triggers, it is important to know what they are, because the allergies cannot be cured. They can only be managed.
Rash Symptoms
Allergic rashes are usually red and itchy. Small or large bumps, called hives, may form in just one spot or all over the body. They may be itchy. Rashes associated with contact dermatitis, a reaction to something to which someone has been exposed, may blister and weep fluid. Alternatively, the rash may be dry and resemble an abrasion, the Mayo Clinic reports. Flaky, scaly red rashes are associated with both contact dermatitis and atopic dermatitis.
Swelling
When an allergic rash accompanies swelling of the face, lips, tongue or throat, it may indicate a food or drug allergy, according to the Cleveland Clinic. Swelling in one area on the body usually indicates an insect sting.
The initial reaction may lead to a severe reaction called anaphylaxis, which can affect breathing, heart rate and digestion. A known allergy to a certain food, drug or insect should be medically managed, and an emergency medication should be carried by the patient.
Nasal Symptoms
An allergic rash that accompanies flu-like nasal symptoms may be two different reactions at the same time, such as atopic dermatitis and hay fever. Symptoms such as a stuffy or runny nose, sneezing and post-nasal drip may be caused by a pollen or leaf mold allergy, according to the University of Maryland Medical Center.
This condition, allergic rhinitis, is commonly called hay fever. A stuffy or runny nose may also accompany a food allergy. Symptoms that lead to extremely difficult breathing may be a sign of anaphylaxis.
Other Respiratory Symptoms
Respiratory symptoms can arise from inhaling cigarette, according to the University of Maryland Medical Center. Coughing, wheezing, chest tightness or shortness of breath can be caused by an insect sting, food or drug sensitivity, the Mayo Clinic notes.
