Symptoms of drug allergies depend on the nature of the reaction. General symptoms include the following:

• Itching of the skin or eyes
• Sensitivity to sunlight (Photosensitivity)
• Skin rash similar to measles
• Hives
• Coughing
• Runny nose
• Wheezing
• Swelling in the face, lips, tongue or throat (angioedema)
• Inflammation of the kidneys

In addition, there are several types of drug-associated allergic reactions that have their own specific symptoms. Serum sickness is a rare condition that affects the entire body and begins six to 21 days after a person takes a medication. Symptoms may include:

• Fever
• Weakness and body aches
• Skin eruptions
• Joint pain

Autoimmune disorders (disorders that are the result of the immune system reacting against the body's own cells) can result from drug allergies, though this is rare. Symptoms of these disorders vary depending on the disease, but may include:

• Fever
• Malaise (general ill feeling)
• Achy joints
• Skin rashes
• Drooping eyelids
• Double vision
• Excessive post-exercise fatigue

Signs and symptoms of anaphylaxis – a reaction involving two or more body systems that can lead to the potentially life-threatening anaphylactic shock – occur within seconds or minutes after a problem drug is taken. They include:

• Difficulty breathing
  
  
• Wheezing
  
  
• Light-headedness
  
  
• Confusion
  
  
• Severe drop in blood pressure
  
  
• Heart palpitations (an awareness of a strong, fast, irregular, abnormal or "galloping" heartbeat)
  
  
• Nausea and vomiting
  
  
• Diarrhea
  
  
• Cramps
  
  
• Bluish tint to the skin (cyanosis), including lips or nail beds
  
  
• Feeling anxious
  
  
• Rapid or weak pulse

Individuals who suspect that they are having an allergic reaction to a medication should contact a physician. The physician will then determine whether or not the patient should stop using the drug. Those experiencing symptoms of anaphylaxis should seek emergency medical attention immediately.