penicillin allergy

• Penicillin is one of the most commonly prescribed antibiotics. It is part of a family of antibiotics known as beta lactams, and there are many individual medications

1- Natural Penicillins e.g. Penicillin G

These have greatest activity against G+ organisms, g – cocci.

2- Penicillinase-resistant Penicillins( antistaphylococal P ) e.g. Cloxacillin,

Dicloxacillin, Methicillin, Nafcillin, Oxacillin.

They are active against staphylococci and streptococci.

3- Extended-spectrum P

e.g. Amoxicillin, ampicillin,

Have further activity against G- organism

• is a hypersensitive state acquired through exposure to a particular allergen.

• An immunologically mediated disease

• Covers broad range of clinical manifestations from mild ,delayed reaction to immediate life threatening reactions

Four types:

Type I HSR : anaphylactic or IgE - mediated

Type II HSR : antibodies-mediated

Type III HSR : immune complex-mediated

Type IV: Cell-mediated (T-cells) or delayed

1-Immunoglobulin(Ig)E antibody-mediated

2-Immediate response

3-allergens(antigens)

A. Dust

B. Mites

C. Pollens

D. Animal danders

E. Food

F. Drugs

4-Symptomes

A. Anaphylaxis

B. Hay fever

C. Asthma

D. Urticaria , angioedema

E. Symptoms on occasion

5-Frequency:affect about 10% of population

6-Iherited tendency

• Penicillin allergy is an abnormal reaction of your immune system to the antibiotic drug penicillin

• A penicillin allergy is an allergic reaction that occurs when your body's immune system overreacts to penicillin antibiotic

Skin rashes

Hives itchingShortness of

breath

wheezing

swelling

anaphylaxis

Itchy ,watery eyes

Runny nose

fever

• Anaphylaxis is a rare, life-threatening allergic reaction that causes the widespread dysfunction of body systems. Signs and symptoms of anaphylaxis include:

1. Itching of soft palate2. Nausea , vomiting3. Sub sternal pressure4. Shortness of breath5. Hypotension6. Urticaria7. Laryngeal edema8. Bronchospasm9. Cardiac arrhythmias

• Serum sickness

• Drug induced anemia

• Drug reaction with eosinophilia and systemic symptoms (DRESS)

• Inflammation in the kidneys (nephritis)

1. A history of other allergies, such as food allergy or hay fever

2. Allergic reaction to another drug3. A family history of drug allergy4. Increased exposure to penicillin, because of

high doses, repetitive use or prolonged use5. Certain illnesses commonly associated with

allergic drug reactions, such as infection with HIV or the Epstein-Barr virus

• Skin tests• With a skin test, the allergist or nurse

administers a small amount of the suspect penicillin to your skin either with a tiny needle that scratches the skin or an injection. A positive reaction to a test will cause a red, itchy, raised bump.

• A positive result indicates a high likelihood of penicillin allergy. A negative test result usually means you're not allergic to penicillin, but a negative result is more difficult to interpret because some kinds of drug reactions cannot be detected by skin tests

I. Treatment for the present allergy

symptoms

II. Desensitization to penicillin

1-Treating current symptoms

• Withdrawal of the drug.

• Antihistamines.

• Corticosteroids.

• Treatment of anaphylaxis

2-Drug desensitization

1. Inform health care workers

2. Wear a bracelet

3. Have an emergency kit

• Urticarial swelling or angioedema

• Reaction is rapid lesion developing within short time

• Painless soft tissue swelling may cause itching and burning

• Lesion can be present for 1-3 days if untreated but will resolve spontaneously

• Oral antihistamine(oral diphenhydramine) 50 mg/4hrs for (1-3days)

1. Urticaria or angioedema

A. Reaction occur soon after contact with antigen

B. Reaction consist of painless swelling

C. Itching and burning may occur

D. Lesion may remain for 1-3 days

1. Reaction not involving tongue , pharynx or larynx and with no respiratory distress noted requires 50 mg of diphenyhydramine 4 times a day until swelling diminshes

2. Reaction involving tongue , pharynx or larynx with respiratory distress noted requires the following:

A. 0.5ml of 1:1000 epinephrine , IM or SC

B. Oxygen

C. Once immediate danger is over,50 mg of diphenhydramine should be given 4 times a day until swelling diminishes

1. Call for medical help

2. Place patient in supine position

3. Check for open airway

4. Administer oxygen

5-Check pulse , blood pressure and respiration.

• If any of vital signs is depressed or absent inject o.5ml 1:1000 epinephrine into tongue

• Provide cardiopulmonary resuscitation if needed

• Repeat IM injection of 0.5 ml 1:1000 epinephrine if no response

I. Tetracycline (e.g. doxycycline)

II. quinolones (e.g. ciprofloxacin)

III. macrolides (e.g. clarithromycin)

IV. aminoglycosides (e.g. gentamicin)

V. glycopeptides (e.g. vancomycin)

1. Erythromycin or clindamycin for treatment of oral infection

2. Or clindamycin for prophylaxis against infective endocarditis

• Don’t use aspirin

• Patient with history of penicillin reaction :1st

skin test for penicillin sensitivity

A. Negative –use penicillin or cephalosporin

B. Positive:

1. Avoid penicillin

2. Skin test for cephalosporin ;use it if result is negative

• ELECTIVE DENTAL CARE:

• Elective dental case requiring local anasthesia may need to be postpondeduntil a thorough evaluation of the patient is completed by a competent individual

• Option 1: consultation

• Immediate consultation to test the patient for allergy to LA.

• If pain is present it may be managed orally with various analgesics and infections can be controlled with antibiotics

• Option2:General anasthesia

• Use of GA in place of LA to manage the dental emergency.

• Highly useful and relatively safe technique but has complications and unavailability in dental office

Option 3:Histamine Blocker

1. Use of histamine blocker like diphenhydramine as LA.

2. 1%solution with 1 in 100,000 epinephrine,pulpalanasthesia upto 30 mins is produced

3. Burning or stinging sensation is produced which can be minimized by using nitrous oxide and O2

4. Post operative tissue swelling and soreness maybe present

Appropriate drug therapy with immediate medical

consultation(option 1)is the most reasonable mode of action

1. Dentist should obtain from each patient a history of any reaction

2. Avoid contact with or use of antigens

3. Most of allergic patient can receive any dental treatment as long as the antigen is avoided and precautions are taken for patient receiving steroids or have angioedema