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Penicillin allergy
Last reviewed: 04.07.2025
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Penicillin allergy is a very pressing problem both in childhood and adulthood. It is associated with the response of the human immune system to the production of specific IgE (immunoglobulin E) and the appearance of immune complexes in combination with other groups of antibodies. It should be noted that penicillin is a low-molecular substance, the emergence of antigenic properties of which is due to a covalent bond with an endogenous carrier protein.
Allergy to penicillin is most common in the age group of 20 to 49. During a person's life, sensitivity to penicillin may decrease or disappear completely. The prevalence of allergy to penicillin ranges from 0.75 to 0.8%, anaphylactic shock is observed in no more than 0.01% of cases.
[ How does penicillin allergy manifest itself?
An allergic reaction will not take long to appear. Allergy to penicillin manifests itself in different ways and is divided by the speed of the onset of symptoms, subject to the repeated administration of the drug. It can be:
- early – appears after 30 minutes in the form of urticaria, anaphylactic shock;
- delayed - occurs after 2-72 hours, manifests itself as itching of the skin, redness of the skin, spasm of the bronchi, swelling of the larynx;
- late - after 72 hours, accompanied by the appearance of skin dermatitis, maculopapular rash, fever, arthralgia.
Rare, severe manifestations of penicillin allergy include Stevens-Johnson and Lyell syndromes, interstitial nephritis, systemic vasculitis, hemolytic anemia, neuritis, etc.
If it is possible to replace penicillin with another antibiotic, then skin tests to identify the allergen are not performed. This is due to the fact that the development of allergies to medications is unpredictable, and diagnostics by skin testing is valuable in a strictly limited time interval. These tests also do not predict the occurrence of side effects in the patient.
Along with skin tests that detect allergy to penicillin, a radioallergosorbent test is performed, which is less sensitive, requires more time, is specific, and does not detect IgE to small amounts of penicillin antigenic determinants.
Penicillin allergy in children
A child's allergy to penicillin is considered a serious problem. After all, it is in childhood that infectious diseases occur that are treated with antibiotics of the penicillin group. Children develop a rash, which is often associated with an allergic reaction to this antibiotic. The main thing here is not to panic and understand that the infectious disease itself can cause a rash on the skin. Only 1% of children actually have an allergy to penicillin. Children with allergies are not predisposed to allergies to antibiotics of the penicillin group. Therefore, the presence of asthma in a child does not mean that penicillin is contraindicated for him. Anaphylactic shock occurs in 0.2% with penicillin injections.
In a child, an allergy to penicillin manifests itself in:
- skin - itchy or maculopapular rash, less commonly Stevens-Johnson syndrome and toxic epidermal necrolysis;
- respiratory tract - in the form of swelling of the larynx, asthmatic condition.
The precursors of anaphylactic shock are: itching, low blood pressure, redness and spasm of the bronchi. After the use of penicillin, the following are also noted: increased temperature, anemia, erythroderma, nephritis.
Penicillin Allergy: Treatment
When the first signs of an allergy to penicillin are detected, it is recommended to immediately seek emergency medical care. In the most severe situations, epinephrine is administered. The dosage is selected depending on the situation. In case of bronchospasm in children and anaphylaxis, a maximum of 0.3 mg is prescribed with the possible administration of the specified dose up to 3-4 times every 15 minutes. The dosage for newborns is 10-30 mcg / kg in an interval of 3-5 minutes. Children over one month old are administered 10 mcg / kg of the drug with a subsequent increase in the dose to 100 mcg / kg every 3-5 minutes. Adults with anaphylactic shock are administered 0.1-0.25 mg of the drug diluted in 10 ml of 0.9% NaCl solution. If necessary, repeat the administration up to three times every 10-20 minutes.
Penicillin allergy is treated with a course of intravenous injections of corticosteroids and antihistamines, which show good results in the early stages of the disease. In case of previously recorded anaphylaxis to penicillin, you will need to use "epinephrine".
An allergic reaction to this antibiotic can be fatal. If red spots, breathing problems, and a positive skin test for penicillin occur, the medication should be replaced immediately.
Amoxiclav for penicillin allergy
Amoxiclav is available in tablets and dry powder for suspension. "Amoxiclav" has a wide range of applications. It is prescribed to combat infections caused by sensitive strains of microorganisms. It is successfully used for gynecological problems, treatment of the gastrointestinal tract, ENT organs, infectious diseases of the skin, urinary tract, etc.
Amoxiclav is an antibiotic of the penicillin group, consisting of the active substance amoxicillin and clavulanic acid. The principle of its action is based on the destruction of cells of pathogenic bacteria. It is destructive to most microorganisms, including: streptococci, shigella, escherichia, proteus, enterococci and others.
Amoxiclav for penicillin allergy can be used as a medicine strictly as prescribed by a doctor. Contraindications include sensitivity to cephalosporins and beta-lactam antibiotics, infectious mononucleosis (including measles-like rash). Only under the supervision of a doctor is the medicine prescribed to pregnant women, during lactation, for gastrointestinal problems and liver diseases.
An allergy to penicillin may not manifest itself when taking amoxiclav, since the body responds to some penicillins with an allergy, and may simply be sensitive to others of the same group. Do not forget that amoxiclav has an impressive list of side effects. These may include various skin reactions, anaphylactic shock, angioedema and Stevens-Johnson syndrome. Therefore, the drug is used after consultation with the attending physician.
How to prevent penicillin allergy?
Prevention is understood as the introduction of a small amount of penicillin with subsequent gradual increase in the dose to obtain a stable result without signs of allergy to penicillin. This method helps the body adapt to the antibiotic and perceive it without allergic reactions, which completely disappear over time. This procedure has one drawback - it does not give a long-term result, so before the next course of penicillin, it will need to be repeated.
Sometimes, after the introduction of penicillin, skin rashes resembling measles are observed. It is important to understand that this is not an allergy to penicillin. Every medical drug has side effects and penicillin is no exception. Therefore, you should not frantically start taking antihistamines. Suspected penicillin allergy may be caused by the action of other antibiotics taken simultaneously with penicillin.