Prior to many medical treatments, doctors ask their patients if they have allergic reactions to any medicines. While physicians can anticipate a drug interaction, they cannot predict a drug allergy. The signs build swiftly, sometimes reaching a life-threatening state called anaphylaxis within minutes of ingesting a medication.
Fortunately, knowledgeable health care personnel administer and supervise some common allergenic compounds such as penicillin and contrast dyes used in medical testing. They can spot allergy symptoms early on and provide treatment.
Itchiness
Allergic reactions to antibiotics, sulfa drugs, anticonvulsants and other medicines often produce itching as blood histamine levels rise. Patients frequently report itchy eyes and skin. These and other allergy symptoms usually develop immediately, although MayoClinic.com notes that sometimes weeks of sensitization precede an attack. Patients beginning a new drug regimen should be alert to seemingly insignificant physical changes, including itching.
Skin Rash
The University of Maryland (UM) Medical Center calls a skin rash another common sign of a drug allergy. Patches of redness may show raised areas, or hives, and the skin may have localized itching. These conditions indicate inflammation brought on by an allergic reaction to an antibiotic or other medicine. Patients should discuss any drug reaction symptoms with their physicians.
Swelling
Swelling of the lips and face constitute signs of a possible drug allergy. Another inflammatory consequence, swelling threatens patients' breathing when it occurs in the mouth and throat. This may induce wheezing and shortness of breath, which can escalate to serious anaphylactic conditions, notes the UM Medical Center.
Digestive Problems
The systemic nature of an allergic reaction to ingested medicines spreads allergy symptoms throughout the body. As the drug allergens travel through the digestive system, patients may experience vomiting in an effort to expel them.
According to the Cleveland Clinic, abdominal pain, nausea and diarrhea may also occur, and these indicate the onset of anaphylaxis. Patients should call 911 for paramedic assistance.
Respiratory Failure
As anaphylactic allergy symptoms progress, the airways constrict, and patients find it more difficult to breathe and talk. The UM Medical Center relates that conditions of mental confusion, dizziness and light-headedness may precede fainting and anphylactic shock. A loss of consciousness should be considered a sign of a medical emergency.
Heart Trouble
A drug allergy may trigger a sharp decline in patients' blood pressure along with an uneven pulse, MayoClinic.com reports. In rare cases, the heart conditions created by this extreme anaphylactic reaction can lead to cardiac and respiratory arrest and death.
