How to know if i have had an allergic reaction?

Symptoms: If the allergy is to a food or ingested medication, the typical symptoms are vomiting, diarrhea and rash (hives, itching). If trigger was airborne like pollen or pet dander, then itching (nose, skin, eyes), sneezing, runny nose and cough. Asthma symptoms can be from an allergy. An allergist can assist in identifying is symptoms are from an allergy and determine specifically which allergen.