What are the other Names of this Condition? (Also known as/Synonyms)

• Allergy to Penicillin

What is Penicillin Allergy? (Definition/Background Information)

• Penicillin Allergy is a very common condition that manifests as an abnormal immune reaction/response to antibiotics belonging to the penicillin family of drugs. These drugs may be administered orally or intravenously. The condition is observed in both children and adults
• Penicillin is a common group of antibiotic medication that is used in the treatment of several bacterial infections. In some cases, it is a highly-effective and the only reliable antibiotic available for certain treatments
• The medications may be in tablet form, liquid form, or injected form. Penicillin Allergy may occur immediately, or within 1-2 hours following exposure to the drug. The condition may be mild, moderate, or severe
• Numerous signs and symptoms of the allergic reaction may be noted including skin rashes and hives, sneezing, breathing difficulties, nausea and vomiting, and indigestion. In some individuals, Penicillin Allergy may lead to an anaphylactic shock, which is a medical emergency
• Penicillin Allergies may be diagnosed through a skin-prick test. The diagnosis can also help identify the specific drugs containing the allergen that are to be avoided (in future)
• Anti-allergic medications form the first line of treatment for mild cases of Penicillin Allergies. Intravenous corticosteroid therapy may be necessary to reduce inflammation. However, in the case of a severe allergic reaction (anaphylaxis), epinephrine injections are recommended
• The prognosis of Penicillin Allergy may be assessed on a case-by-case basis, but in most cases, it is generally good. Many individuals overcome the condition over time (after about 10 years)

Who gets Penicillin Allergy? (Age and Sex Distribution)

• Penicillin Allergies are common hypersensitivity reactions to the penicillin class of drugs that occur in both children and adults
• Studies indicate that as many as 1 in 10 individuals may be allergic to penicillin
• No gender preference is noted and both males and females are affected
• All racial and ethnic groups are equally vulnerable to the condition

What are the Risk Factors for Penicillin Allergy? (Predisposing Factors)

The common risk factors for Penicillin Allergy include:

• Use of the drug in pill or liquid form
• Any family history of Penicillin Allergy
• Infants and young growing children may have a higher risk

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Penicillin Allergy? (Etiology)

An allergic reaction occurs in an individual with Penicillin Allergy, because the immune system recognizes certain substances/components in the drug as being dangerous and harmful to the body.

• Intake of the penicillin drug results in the production of antibodies, specifically immunoglobulin E (IgE). The next time the individual is exposed to the particular drug, the antibodies that are circulating in blood causes an antibody-antigen reaction
• This results in the production of histamine and other chemical messengers, which cause the symptoms seen during an allergic reaction
• The quantity of medicine that triggers an allergy may not be significantly large. Sometimes, consuming tiny amounts of the allergen is sufficient to trigger the condition

In some cases, a severe allergic reaction termed as anaphylaxis may occur, which is a medical emergency that requires immediate medical attention. Studies indicate that almost 1 in 10,000 individuals with Penicillin Allergy develop anaphylaxis.

What are the Signs and Symptoms of Penicillin Allergy?

The signs and symptoms of Penicillin Allergy may start to appear within a few minutes, to a couple of hours, after the individual has been administered the medicine. In some, the symptoms are mild, while in others they are severe. A severe allergic reaction is a medical emergency.

The common signs and symptoms of Penicillin Allergy may include:

• Itching of skin
• Urticaria (hives) and/or angioedema
• Swollen lips and tongue, swollen face
• Tightening of throat
• Hoarseness
• Shortness of breath (trouble breathing), wheezing, asthma-like symptoms
• Runny or stuffy nose
• Watery eyes, redness, and irritation
• Increase in pulse rate, palpitations
• Low blood pressure (hypotension)
• Nausea and vomiting
• Diarrhea
• Abdominal cramps and pain
• Confusion and dizziness
• Cardiovascular shock
• Loss of consciousness, fainting

Generally, not all episodes of allergy will be of the same severity. In some individuals, the most severe symptom caused by certain Penicillin Allergies is anaphylaxis.

• Anaphylaxis (sometimes called an anaphylactic shock) is a life-threatening, whole-body allergic reaction
• During anaphylaxis, tissues in various body parts release histamine and other messenger chemicals, which causes swelling of the throat and other symptoms
• Swelling of the throat is especially dangerous as this can cause shortness of breath. If the swelling is not reduced soon, then there is a possibility that the individual could die from a lack of sufficient oxygen
• It can also result in a bluish skin, weak pulse, and decreased blood pressure (hypotension)

How is Penicillin Allergy Diagnosed?

The diagnosis of Penicillin Allergy may involve the following:

• Physical examination, assessment of symptoms, and medical history evaluation (history of allergies in the family)
• Evaluation of complete list of medications being taken by the individual
• A consultation with an allergy specialist is very helpful in many cases

The tests that are usually conducted to diagnose Penicillin Allergy include:

• Oral drug challenge testing; when the individual is administered the allergens in a controlled manner to check for symptoms that develop
• Radioallergosorbent (RAS) test; to determine the specific allergy-causing substance
• Penicillin skin-prick test: This is a reliable test for Penicillin Allergy
  • For this test, tiny amounts of certain substances are injected right underneath the skin (forearm, upper arm, or back)
  • After 15-20 minutes, if the spot where the chemical was injected swells, or if there is redness noticed, then this indicates that the individual may be allergic to the substance
• Blood test to detect antibodies (IgE antibody test)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Penicillin Allergy?

The complication of Penicillin Allergy is associated with the allergic reaction itself and it depends on the severity of the reaction. It may include:

• Anaphylactic shock/reaction that may be life-threatening
• Serum sickness (type 3 hypersensitivity reaction), which may occur after 1-3 weeks 
• Having allergy to one type of a drug can make the individual prone to other drug allergy types
• In severe reactions, a tracheostomy may have to be performed during an emergency situation

How is Penicillin Allergy Treated?

The treatment of Penicillin Allergy may be undertaken in the following manner:

• Avoiding penicillin drugs and all related drugs containing penicillin
• Anti-allergic medication for mild reactions; antihistamine therapy, that is prescribed by the allergy physician
• Symptomatic treatment; use of decongestants, especially for nose block including steroid sprays
• Corticosteroid therapy to reduce inflammation (administered orally or via injections)
• In the case of anaphylaxis (severe allergic reaction), epinephrine or adrenaline is immediately administered
• Breathing support as necessary, control asthma symptoms and low blood pressure
• Bronchodilators for respiratory conditions such as asthma, wheezing, etc.

Penicillin desensitization therapy to make the individual get used to the drug. This is undertaken when no suitable alternative medication is available to treat the condition. However, this does not ensure that the body has completely got used to the allergic drug.

How can Penicillin Allergy be Prevented?

It may not be possible to completely prevent Penicillin Allergy; however, the following factors may be considered:

• Immediately inform the healthcare provider if you experience any side effects to a drug or other symptoms; this may help the physician evaluate for a drug allergy
• Studies have shown that breastfeeding children for 4-6 months or over, can help build their body immunity and make them less prone to allergies
• Appropriate maternal diet during pregnancy can help build stronger resistance (against allergies) in children
• Use alternative medications, where possible

In case the child or adult is susceptible to an anaphylactic shock (high-risk individuals) from Penicillin Allergy, the following should be considered:

• Being watchful of triggers and avoiding them
• Wearing medical alert information bracelets or suitable devices
• Carry auto-injector epinephrine or adrenaline medications such as EpiPen, Anapen, or Twinject. Since the condition may recur, it is advised to carry 2 doses (2 pens)
• Supervise children on how to self-administer the injection, if required
• If child is prone to anaphylactic reaction, then information (preferably written instructions) should be given to day care, school authorities accordingly
• Adults should inform their spouses, colleagues, and friends, about the condition, in case of a future emergency

What is the Prognosis of Penicillin Allergy? (Outcomes/Resolutions)

The prognosis of Penicillin Allergy depends on the severity of the signs and symptoms. It is generally assessed on a case-by-case basis.

• In many cases, the prognosis is good with adequate treatment. 4 in 5 individuals are known to overcome the allergy over time (after as many as 10 years), while few may have it for the rest of their lives
• In some cases, the allergic reaction may be severe, causing anaphylaxis. This is a medical emergency that can lead to a respiratory failure. It requires an immediate treatment of the condition. In such cases, the prognosis is guarded and it depends on whether immediate medical assistance is provided

Individuals, who show severe symptoms, may over time lose their sensitivity to the drug, and the drug may be used in such individuals.

Additional and Relevant Useful Information for Penicillin Allergy:

Please visit our Allergy Health Center for more physician-approved health information:

http://www.dovemed.com/health-topics/allergy-center/