Drug allergy

A drug allergy is an unusual and unwanted side effect of medication. Several different types of allergic reactions to medications can occur.

Drug reactions range from a mild localized skin rash to serious involvement of vital organs and systems. The immune response can affect any organ, but it most often manifests itself on the skin.

It is important to recognize the symptoms of a drug allergy because they can be life-threatening. But death due to an allergic reaction to a drug occurs very rarely. In most cases, at the first intake of a drug, an allergic reaction does not develop. A is much more likely to happen on the second intake.

Not all adverse drug reactions are due to allergies. In fact, less than 10% of adverse drug reactions are allergic.

Other possible causes of such reactions are interactions between 2 or more drugs, inability to break down the drug completely by the body, most often this happens with damage to the liver and kidneys, overdose and annoying side effects such as nausea, vomiting or diarrhea.

What are the symptoms?

Drug allergies have many different types of symptoms depending on the drug, as well as the degree of exposure to it /how often it is taken/.

Skin reactions

• A rash similar to that that occurs with measles;
• Hives – red, itchy bumps on the skin with an irregular shape;
• Photoallergy – sensitivity to sunlight, an itchy and scaly rash that appears after exposure to the sun.
• Steven’s syndrome – Johnson – red, swollen and itchy spots on the skin that may appear along with swelling of the face and tongue.
• Muscle and joint pain.
• Unlike most allergic reactions, which occur relatively quickly after exposure to the allergen, drug reactions occur days or weeks after the first dose of the medication.
• Accelerated or uneven heartbeat.
• Swelling of the face, tongue, lips, throat, joints, hands and feet.
• Fainting – light dizziness or loss of consciousness due to a drastic drop in blood pressure.

Not allergic reactions:

• Increased body temperature;
• Swelling of the lymph nodes;
• Inflammation of the kidneys;

What are the causes?

Most often drug allergies are caused by:

• Painkillers called analgesics such as codeine, morphine, nonsteroidal anti-inflammatory drugs such as ibuprofen or indomethacin, and aspirin.
• Antibiotics such as penicillin, sulfamides, and tetracycline.
• Anticonvulsants such as phenytoin or carbamazeline;

Risk factors for the development of allergies from the use of medicinal products:

• Frequent exposure to the drug – potential allergen;
• Intake of large doses of the same;
• The drug is administered by injection, not orally.
• Family history of developing allergies and asthma;
• Some food allergies such as to egg, soy or to shellfish such as shrimp and mussels.

Drug allergy treatment

For urticaria or localized skin reactions, do the following:

• Take a cool shower or apply cold compresses;
• Wear light clothes that do not irritate the skin.
• Rest and do not overexert yourself physically;
• Calamine lotion is applied to relieve itching, although it is not very effective, or you can take antihistamines such as diphenhydramine or chlorpheniramine maleate. New, soluble, non-sedating antihistamines are now available that are fast-acting and have fewer side effects than those previously used.
• Oral steroids may also be prescribed. such as prednisone or histamine blockers such as cimetidine, famotidine or ranitidine.