Medicinal allergy

Drug allergy, more often in clinical practice, denoted by the abbreviation of LA, is a secondary reaction of the immune system to a variety of medications. Drug allergy is accompanied by general clinical symptoms and local, local manifestations. As a rule, the drug allergy comes after a period of sensitization, after "getting to know" the immune system with the allergen. There are no cases of primary LA in clinical practice. That is, an allergic reaction can only be to a re-injected provoking drug.

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Why is there a drug allergy?

Drug allergy is a fairly common phenomenon, although half a century ago such manifestations of allergy were extremely rare. People prone to allergies to medications are conventionally divided into two groups: 

1. Allergy to the drug occurs after a powerful therapy of the underlying disease. Often this disease is allergic, they include many gastrointestinal pathologies and liver diseases. 
2. An allergic reaction occurs as a result of constant contact with medications. It can be pharmacists, doctors, nurses, workers of pharmaceutical plants.

Drug allergy is a serious complication, leading often to a threat not only to health, but also to a person's life. According to statistics, more than 70% of all complications after taking medications are allergies. A lethal outcome occurs in 0.005% of the total number of suffering aircraft. The percentage is very small, which can not but rejoice, but the risk exists. About 12% of all patients receiving drug therapy suffer from drug allergy .. Moreover, these rates are steadily growing due to the general spread of allergic diseases in the world.

Gender preference is also confirmed by statistics. Women are more likely to respond to drugs with allergic reactions than men. For a thousand allergy sufferers who have a histamine reaction due to the fault of medicines, there are 30-35 women, 14 men. Drug allergy targets middle-aged people, mostly people between 30 and 40 years of age. In most cases, the drug allergy occurs after taking antibiotics, they account for 50%. Followed by an anti-tetanus serum, it reacts from 25 to 27% of people. Also dangerous for allergy sufferers and not only sulfonamides and NSAIDs are non-steroidal anti-inflammatory drugs. Also, anti-allergic drugs, which, in fact, are designed to block allergies, can also trigger a reaction.

The drug allergy is very insidious, and can after decades "debut" to recur at the moment when a person has already forgotten about it. Factors provoking a drug allergy: 

• Long-term use of the drug, the prescription of drugs of one group, an overdose or an incorrectly calculated dose; 
• Hereditary factor; 
• Long-term contact with medicines (workers in the field of medicine and pharmacy); 
• Mycoses, various kinds of fungal pathologies; 
• The allergy in the anamnesis.

How does the drug allergy develop?

There is a concept of full-fledged allergens, these are all substances of the protein structure - vaccines, dextrans, serums. These substances react with antibodies, which, as a response to the invasion, produce the immune system. Drugs, on the contrary, are combined with proteins and only then become "enemies" - antigens. This is how antibodies are created, with repeated administration of a provoking drug, antibodies are grouped into complexes, triggering an allergic reaction. The aggressiveness of medications depends on the chemical composition and the way the medication is administered. The injection pathway is most preferable for allergies, the antigen functions more quickly and the reaction also occurs quickly. Oral administration of allergic agents causes a delayed-type reaction. In the administration of the drug, subcutaneously, provokes an instant allergic reaction.

See also: Allergies to antibiotics

Drug allergies can be true and false. This is an anaphylactoid shock, which requires the same urgent resuscitation as anaphylactic allergic shock. Anaphylactoid reaction occurs without sensitization, the antibody-antibody complex is absent in the body and the cause of the reaction lies in a completely different area. To distinguish pseudo-drug allergy is possible on the following grounds: 

• Allergy occurs after the first administration of the drug; 
• The clinic can also be seen with a placebo; 
• Identical manifestations, reactions to drugs of completely different groups for the purpose and mechanism of exposure; 
• An indirect argument for differentiation is the absence of an allergic anamnesis.

How is the drug allergy manifested?

The drug allergy manifests itself with varying degrees of severity and at different rates:

• Instant reactions - within an hour. 
  • Anaphylactic shock; 
  • Hives in acute form; 
  • Edema Quincke; 
  • Hemolytic anemia in acute form; 
  • Bronchospasm.
• Subacute reactions - within 24 hours. 
  • Thrombocytopenia; 
  • Fever; 
  • Macular papular exanthema; 
  • Agranulocytosis.
• Reactions of a delayed type - within two or three days. 
  • Serum sickness; 
  • Vasculitis and purpura; 
  • Polyarthritis and arthralgia; 
  • Lymphadenopathy; 
  • Jade allergic etiology, allergic hepatitis.

Drug allergy is diagnosed on the basis of clinical manifestations, which manifest often very clearly. A specific therapy is prescribed, which eliminates the symptoms that threaten health and life, of course, the allergy-provoking drug is canceled. Nonspecific therapy is aimed at curating the entire cycle of an allergic reaction.

In general, a drug allergy is a disease caused by: 

• anamnestic individual predisposition; 
• incorrect appointment of drug therapy; 
• improper intake of the drug by the patient; 
• self-medication.