Antibiotics, especially those from the penicillin and sulfonamide groups, are the most common cause of drug allergy.
 X Trusted Sources Visit the American College of Allergy, Asthma and Immunology. Source. Most drug allergies usually cause hives, swelling, and a rash. However, some people experience a rare and life-threatening reaction called anaphylaxis.
 X Trusted Source X Trusted Source Visit the Mayo Source Clinic If you experience symptoms of anaphylaxis, you should seek medical attention immediately.
#1. see a doctor
1. call the doctor If you think you are allergic to an antibiotic, see a doctor right away, regardless of the severity of your symptoms. Many allergic reactions are limited to rashes and do not cause complications, but whatever the reaction, you should tell your doctor. The rash was caused by Stevens-Johnson syndrome, a serious complication that required hospitalization. Other skin rashes are precursors to anaphylaxis, which can be life-threatening if left untreated. See a doctor right away if you notice any of the following:
- Sore throat/mouth, with or without a cough
- facial swelling
- swelling of the tongue
- skin pain
- Rash and/or blisters
- Difficulty breathing or tightness in the throat
- unusually hoarse voice
- hives or swelling
- vomiting or nausea
- stomach pain
- dizziness or fainting
- Fast heart rate
- panic attacks
2. Avoid the allergen. If you are allergic to an antibiotic, you should stop taking the medicine and avoid contact with it. Exposure may be unintentional, so caution is advised.
- Tell your doctor about your allergies whenever you have a treatment.
- Put on a medical bracelet. This bracelet will be very useful to you, especially when you need help in an emergency while you are unconscious. This device alerts allergy healthcare professionals if you fail to inform them of your allergies.
- Carry an emergency adrenaline auto-injector (commonly known as an “epi pen”). This device is usually only needed for people at risk of anaphylaxis, but if you have severe allergies your doctor may recommend an auto-injector.
3. Talk to your doctor about desensitization. If you have a known allergy, in most cases your doctor will prescribe a different medicine. However, in some cases this is not an option. If you need to take certain medications and are allergic to them, your doctor may prescribe desensitization therapy.
- During drug desensitization treatment, your doctor will give you the allergy-causing drug in very small amounts and monitor your symptoms. Then he will give you increasing doses every 15 to 30 minutes for several hours or even days.
- If you can tolerate this dose without side effects, your doctor may prescribe your usual dose of the medicine.
#2. Treatment of allergy symptoms with medication
1. Take oral antihistamines. Antihistamines increase the passage of white blood cells through the body while decreasing the body’s production of histamine. Histamine is released by the immune system in response to an allergy. Depending on the severity of your reaction, your doctor may recommend a prescription antihistamine or advise you to purchase an over-the-counter antihistamine.
- Common over-the-counter antihistamines include loratadine (Claritin), cetirizine (Zyrtec), diphenhydramine (Benadryl), or chlorpheniramine (Aller-Chlor).
- The dose you take depends on several factors, including your age and the specific antihistamine you’re taking. Follow the directions on the package or ask your doctor or pharmacist for dosing instructions.
- Do not drive or use machines after taking an antihistamine.
- Do not take antihistamines if you are pregnant or breastfeeding. These drugs can cause unwanted side effects in the baby and birth defects in the developing fetus.
- Do not give antihistamines to children under the age of four. Consult your child’s doctor before administering any medication, including antihistamines.
- Some elderly patients experience undesirable side effects from antihistamines. These side effects include feeling confused, dizzy, light-headed, nervous and irritable.
2. Apply calamine lotion. If you experience a rash or itching due to an allergic reaction, Calmin Lotion can help relieve the itching and discomfort.
- Calamine Lotion contains calamine, zinc oxide and a blend of other ingredients. Calamine and zinc oxide are well-known topical anti-itch agents.
- Calamine is for external use only. You should not swallow Calmin or apply it around your eyes, nose, mouth, genitals, or anus.
3. Try hydrocortisone cream. Low-dose hydrocortisone cream is available over the counter in concentrations of 0.5-1%, although higher concentrations are available by prescription. This topical medication suppresses the response of your immune system and relieves skin irritation, itching, and rashes.
- Hydrocortisone cream is a topical steroid. This type of medication is generally safe, but should not be used for more than seven consecutive days to avoid complications such as itching, cracked skin, and pimples.
- Topical hydrocortisone should not be used by children under the age of two. Do not use this medication if you are pregnant or breastfeeding unless directed to do so by your doctor.
- Apply to affected areas one to four times a day for seven days. If you wipe your face with it, don’t get it in your eyes.
#3. Use of home remedies and lifestyle changes
1. Take a bath with lukewarm water. Extreme heat and cold can affect hives and make them worse after hives appear. For best results, bath water should be at room temperature to reduce rashes.
- To relieve itching, sprinkle baking soda, raw oatmeal, or finely ground colloidal oatmeal into your bath water.
- Avoid using soap until you know if a particular brand of soap irritates hives.
2. Apply a cold compress. A cold, damp compress can relieve symptoms associated with rashes and hives. Contact with a cold, damp bandage or bandage can help reduce skin irritation and reduce swelling by slowing blood flow to the rash.
3. Avoid obstacles. Many things can irritate hives and rashes. Even if you are not affected by common irritants in your household, it is best to avoid them until you know how your rash/hives are reacting to those irritants. Common problems are:
- beauty products
- Colors (including dyes for clothing)
- fur and leather goods
- hair dye
- Nickel products including jewellery, zippers, buttons and kitchen utensils.
- Nail care products including nail polish and false nails
- soap and household chemicals
4. Try not to scratch or rub. Although your rash can be very itchy, you should avoid scratching or rubbing your rash/hives. Scratching can cause cracks in the skin, leaving you vulnerable to infection and slowing down the healing process.
5. Avoid exposure to heat. For some people, exposure to heat and humidity can make hives and rashes more bothersome. If you get a rash or hives, avoid heat, moisture, and exercise.
6. Wear comfortable clothing. When you have rashes and hives, you need to wear the right clothes so you don’t irritate your skin further. Choose a soft material with a fine texture, such as e.g. cotton. Avoid tight clothing and rough, coarse materials like wool.