A drug allergy is the abnormal reaction of your immune system to a medication.  A drug allergy occurs when your immune system mistakenly identifies a drug as a harmful substance, such as a virus or bacterium. Once your immune system detects a drug as a harmful substance, it will develop an antibody specific to that drug. This can happen the first time you take a drug, but sometimes an allergy doesn’t develop until there have been repeated exposures. The next time you take the drug, these specific antibodies flag the drug and direct immune system attacks on the substance. Chemicals released by this activity cause the signs and symptoms associated with an allergic reaction.  You may not be aware of your first exposure to a drug, however. Some evidence suggests that trace amounts of a drug in the food supply, such as an antibiotic, may be sufficient for the immune system to create an antibody to it.  Any medication – over-the-counter, prescription or herbal – is capable of inducing a drug allergy. However, a drug allergy is more likely with certain medications. A drug allergy is not the same as a drug side effect, a known possible reaction listed on a drug label. A drug allergy is also different from drug toxicity caused by an overdose of medication.

Drugs commonly linked to allergies

Although any drug can cause an allergic reaction, some drugs are more commonly associated with allergies. These include:

• Antibiotics, such as penicillin
• Pain-relievers, such as aspirin, ibuprofen (Advil, Motrin) and naproxen sodium (Aleve)
• Chemotherapy drugs for treating cancer
• Medications for autoimmune diseases, such as rheumatoid arthritis

Nonallergic drug reactions

Sometimes a reaction to a drug can produce signs and symptoms virtually the same as those of a drug allergy, but a drug reaction isn’t triggered by immune system activity. This condition is called a nonallergic hypersensitivity reaction or pseudoallergic drug reaction. Drugs that are more commonly associated with this condition include:

• Aspirin
• Dyes used in imaging tests (radiocontrast media)
• Opiates for treating pain
• Local anesthetics

Symptoms of Drug Allergy

The most common signs and symptoms of drug allergy are hives, rash or fever. A drug allergy may cause serious reactions, including a life-threatening condition that affects multiple body systems (anaphylaxis). Signs and symptoms of a serious drug allergy often occur within an hour after taking a drug. Other reactions, particularly rashes, can occur hours, days or weeks later.

Drug allergy signs and symptoms may include:

• Skin rash
• Hives
• Itching
• Fever
• Swelling
• Shortness of breath
• Wheezing
• Runny nose
• Itchy, watery eyes

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

• Tightening of the airways and throat, causing trouble breathing
• Nausea or abdominal cramps
• Vomiting or diarrhea
• Dizziness or lightheadedness
• Weak, rapid pulse
• Drop in blood pressure
• Seizure
• Loss of consciousness

Other conditions resulting from drug allergy

Less common drug allergy reactions occur days or weeks after exposure to a drug and may persist for some time after you stop taking the drug. These conditions include:

• Serum sickness – which may cause fever, joint pain, rash, swelling and nausea
• Drug-induced anemia – a reduction in red blood cells, which can cause fatigue, irregular heartbeats, shortness of breath and other symptoms
• Drug rash with eosinophilia and systemic symptoms (DRESS) – which results in rash, high white blood cell count, general swelling, swollen lymph nodes and recurrence of dormant hepatitis infection
• Inflammation in the kidneys (nephritis) – which can cause fever, blood in the urine, general swelling, confusion and other symptoms

The most severe form of delayed drug reactions not only cause rashes but may also involve other organs including the liver, kidneys, lungs, and heart. Blisters may be a sign of serious drug reactions called Stevens-Johnson Syndrome and Toxic epidermal necrolysis (TEN), where the surfaces of your eye, lips, mouth and genital region may be eroded.

Risk factors

While anyone can have an allergic reaction to a drug, a few factors can increase your risk. These include:

• A history of other allergies, such as food allergy or hay fever
• A personal history of drug allergy
• Increased exposure to a drug, because of high doses, repetitive use or prolonged use
• Certain illnesses commonly associated with allergic drug reactions, such as infection with HIV or the Epstein-Barr virus
• Contrary to popular myth, a family history of a reaction to a specific drug typically does not increase your chance of reacting to the same drug.

Diagnosis of Drug Allergy

Drug allergies can be hard to diagnose.

Your allergist will want to know the answers to these questions:

• What drug do you suspect caused your reaction?
• When did you start taking it, and have you stopped taking it?
• How long after you took the drug did you notice symptoms, and what did you experience?
• How long did your symptoms last, and what did you do to relieve them?
• What other medications, both prescription and over-the-counter, do you take?
• Do you consume herbal medications or take vitamin or mineral supplements?

Depending on the drug suspected of causing the reaction, your allergist may suggest a skin test or, in very limited instances, a blood test. An allergy to penicillin-type drugs is the only one that can be definitively diagnosed through a skin test. If a drug allergy is suspected, your allergist may also recommend an oral drug challenge, in which you will be supervised by medical staff as you take the drug suspected of triggering a reaction. (If your reaction was severe, a drug challenge may be considered too dangerous.)

Prevention

If you have a drug allergy, the best prevention is to avoid the problem drug. Steps you can take to protect yourself include the following:

• Be sure that your drug allergy is clearly identified in your medical records.
• Inform your health care providers including other providers, such as your dentist or any medical specialist.
• Ask about related drugs that you should avoid.
• Ask about alternatives to the drug that caused your allergic reaction.
• Wear a medical alert bracelet that identifies your drug allergy. This information can ensure proper treatment in an emergency.
• If a severe life-threatening reaction (anaphylaxis) occurs, use your epinephrine auto injector and call 911.

A Few Words About Penicillin Allergy

Penicillin, discovered by Alexander Fleming in 1928, is prescribed today to treat a variety of conditions, such as strep throat. Despite its effectiveness, some people steer clear of penicillin for fear of experiencing an allergic reaction to the medication. Nearly everyone knows someone who says they are allergic to penicillin. Up to 10% of people report being allergic to this widely used class of antibiotic, making it the most commonly reported drug allergy. With that said, studies have shown that more than 90% of those who think they are allergic to penicillin, actually are not. In other words, 9 out of 10 people who think they have penicillin allergy are avoiding it for no reason. Even in people with documented allergy to penicillin, only about 20% are still allergic ten years after their initial allergic reaction!

Anyone who has been told they are penicillin allergic, but who hasn’t been tested by an allergist, should be evaluated. An allergist will work with you to find out if you are truly allergic to penicillin, and to determine what your options are for treatment if you are. If you’re not allergic to penicillin you will be able to use medications that are safer, often more effective and less expensive.

Hives, the common term for urticaria, may appear as blotches or raised red bumps (wheals), caused by irritation in the upper layers of the skin. They can be pale or red in color and are very itchy. The bumps are often oval or round, but also can be other shapes. They are usually 1 to 2 cm in size (about the size of a quarter) but can be larger. They may combine with nearby hives as they grow to form larger hives. The individual lesions usually disappear within minutes to hours but may return elsewhere. Once faded, they leave no marks other than scratches from itching. They may come and go for days or weeks, sometimes longer. In most cases hives are not due to a specific allergy. When hives occur most days for more than six weeks this is defined as chronic urticaria.

Hives are common. Up to 1 in 5 people (20%) of people will develop hives at some time during their life. However, in only 1 in 100 (1%) will they last for over 6 weeks. In most cases, hives are not due to allergy. Underneath the lining of the skin and other body organs are blood cells known as Mast cells. Mast cells contain natural chemicals including histamine. When these are released into the skin, they irritate nerve endings to cause local itch and irritation and make local blood vessels expand and leak fluid, triggering redness and swelling.

Hives can also cause deeper swellings in the skin, and this is called angioedema. These swellings are often bigger, last longer, may itch less, sometimes hurt or burn and respond less well to antihistamines. Large swellings over joints, for example, can cause pain that feels like arthritis, even if the joint is not involved. Angioedema most frequently affects the face and lips. Although hives and facial swelling can be uncomfortable and cosmetically embarrassing, they are not usually dangerous. Rarely, angioedema (swelling) occurs without hives. This may suggest a special situation requiring additional evaluation.

Hives are rarely due to a serious underlying disease. Often the cause of hives in not obvious. Infection from a virus is the most common cause of hives in children. Contact allergy to plants or animals may cause localized hives. Allergic reactions to food, medicines or insect stings can appear as hives. They usually occur within one to two hours of exposure and disappear in most cases within six to eight hours. An allergic cause may be suspected if episodes are rare, short-lived and occur under specific circumstances (e.g., Only when exercising, always within two hours of a meal or when symptoms involving other organs occur around the same time, such as stomach pain, vomiting, difficulty breathing or dizziness).

Chronic urticaria is defined when hives occur most days for more than six weeks. Symptoms of chronic urticaria usually resolve, although this can take months or several years. Chronic hives can last for many years but will often go away. In these individuals, hives will resolve in half of patients within 1-2 years and 80-90% of patients will improve within 5 years. Even if a patient’s hives improve, it is not unusual to see the hives recur months to years later. Ongoing hives lasting days at a time are almost never allergic in origin. Usually, the cause of chronic urticaria cannot be identified. The absence of an identifiable trigger can be frustrating for patients. Stress is a very rarely the cause of hives but may make the symptoms worse. In some people hives are caused by physical triggers, including cold, heat, sunlight, vibration, rubbing or scratching of the skin (called dermatographism), and delayed pressure (such as after carrying heavy bags).

Most people with hives do not need allergy tests. Tests are sometimes done when hives go on for long periods of time, or when unusual symptoms are occurring around the same time. This is to exclude other diseases, which may appear as hives first. If hives are associated with high fever, bruising, bleeding into the skin, purple lumps that last for several days, or sore joints, a doctor’s appointment should be scheduled. Allergy testing is performed when the history suggests an allergic cause.

Treatment may not be needed if the hives are mild. They may disappear on their own. To reduce itching and swelling consider the following: Do not take hot baths or showers; Do not wear tight-fitting clothing, which can irritate the area;). Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) should be avoided as they can make symptoms worse.  Non-sedating antihistamines such as Allegra (fexofenadine), Zyrtec (cetirizine) or Claritin (loratadine) are often used to reduce the severity of the itch and reduce hives. Medications will not “cure” hives but may help to completely resolve them. Antihistamines are the best initial medication to treat your hives. Sometimes, a combination of several antihistamines or an increased dose of one antihistamine may be recommended. Corticosteroids, such as prednisone may help hives. These are not an ideal treatment for long-term use but may have a role to relieve severe symptoms for a few days.  Other oral prescription medicines may be needed, especially if the hives are chronic (long-lasting).  For those with chronic hives that do not respond to these therapies injection therapy with Xolair (omalizumab) may be an option that is recommended.

The sinuses are hollow air pockets (cavities, spaces) in the bones of the face and head that probably exist to cushion the brain during trauma. There are four paired sinus cavities in the head. These spaces are connected by narrow channels. The four spaces are named for the bones they are near: ethmoidal, sphenoidal, frontal and maxillary. The sinuses are lined with a thin layer of tissue that normally makes a small amount of mucus to keep the sinuses healthy and lubricated. This drainage works as a filtration system, keeping the nose clean and free of bacteria. Rhinosinusitis occurs when the lining of the sinuses gets infected or irritated, become swollen, and create extra mucus. The swollen lining may also interfere with drainage of mucus.

Chronic sinusitis refers to a condition that lasts at least 12 weeks, despite attempts to treat it, and causes at least two of the following symptoms:

• Nasal congestion
• Mucus discharge from the nose or mucus that drips down the back of the throat
• Facial pain, pressure, or “fullness”
• A decreased sense of smell

Common signs and symptoms of chronic sinusitis include:

Nasal inflammation, Thick, discolored discharge from the nose (runny nose), Drainage down the back of the throat (postnasal drainage), Blocked or stuffy nose causing difficulty breathing through your nose; Pain, tenderness and swelling around your eyes, cheeks, nose or forehead; Reduced sense of smell and taste, Ear pain, Headache, Aching in your upper jaw and teeth, Cough or throat clearing, Sore throat, bad breath, Fatigue

Chronic sinusitis can be caused by several factors. These include:

• Blocked airways from asthma or allergies or from conditions such as cystic fibrosis.
• Infections, which can be bacterial, viral or rarely fungal.
• Exposure to tobacco smoke or airborne irritants (e.g., environmental toxins, such as formaldehyde).
• Abnormal nose structures, such as a deviated septum (actually a rare cause of chronic sinusitis) or nasal polyps.
• Immune system disorders – e.g., antibody deficiency (hypogammaglobulinemia).

Diagnosis

Chronic rhinosinusitis is likely if a person has had two or more of the symptoms listed above for a period of at least three months. In addition, there should be evidence of sinus disease that can be seen on a sinus CT scan or with a procedure called sinus endoscopy. A sinus CT scan is a procedure that takes about 15 minutes and involves a series of radiographs of the head and face. The radiographs give a detailed picture of the sinus linings and any mucus or polyps within the sinus spaces. A CT scan could also be used to look for structural issues. Structural problems usually include a deviated nasal septum, bony spurs or nasal polyps. Sinus endoscopy is an office procedure performed by an ENT specialist in which a clinician uses a thin tube attached to a camera to see inside the sinuses.

Treatment

Unfortunately, chronic sinusitis cannot be cured in most cases, but the symptoms can be managed so that they are not so burdensome. People with chronic sinusitis usually need life-long treatment to keep the symptoms in check. Several treatment options are available, but not all treatments are appropriate for all people. Health care providers usually recommend starting with aggressive treatment to get symptoms and inflammation under control and then changing to a less aggressive approach over time.

Potential treatments for chronic rhinosinusitis include:

Lifestyle modifications – People with chronic sinusitis who smoke cigarettes should stop. People who have environmental allergies should maximize avoidance strategies.

Daily nasal saline washing – Most people with chronic sinusitis find that washing their nasal passages daily with saline (salt water) helps reduce symptoms. Washing the nose before applying medications also clears away mucus and allows nasal medications to be absorbed better. A variety of devices, including squeeze bottles and Neti pots may be used to perform nasal irrigation. These are available without a prescription.

Steroid nasal sprays – Because all forms of chronic rhinosinusitis involve some degree of inflammation most people will need medications to reduce inflammation. Sprays do not reach deep into the sinus cavities, but they reduce swelling in the nasal passages and open the areas through which the sinuses drain.

Steroid pills – Are very effective anti-inflammatory drugs. They also decrease mucus production and help shrink nasal polyps. Oral steroids get into the circulation and deliver higher doses of drug compared with nasal sprays. This can result in better treatment of the inflammation and more dramatic improvement in symptoms. However, oral steroids can be associated with a variety of unwanted side effects and their use should be minimized.

Antibiotics – Although chronic sinusitis is often caused by inflammation rather than infection, sinus infections can develop and aggravate symptoms. As a result, you may need to take antibiotics. It is sometimes recommended to take a long course of antibiotics, lasting several weeks, to fully treat a sinus infection in a person with chronic sinusitis.

Surgery – Although health care providers usually attempt to get the symptoms of chronic sinusitis under control with medication first, some people need surgery to reopen the sinus passages and remove trapped mucus or polyps. Situations in which surgery is helpful include the following:

• When chronic rhinosinusitis symptoms do not improve enough with the medical treatments mentioned above and there is evidence of persistent sinus disease on sinus CT scan, such as complete blockage of one or more sinuses.
• When nasal polyps are present that do not sufficiently shrink with medical treatment.
• When there is severe deviation of the septum or other sinus anatomic problems causing nasal blockage or difficulty with sinus drainage.

Though surgery can be very useful in the treatment of chronic sinusitis by itself it is rarely enough to control symptoms long-term. The factors that caused the sinus linings to become irritated and swollen and produce extra mucus in the first place must still be addressed.

Can you prevent chronic sinusitis?

You may be able to prevent infections and chronic sinusitis if you:

• Treat the underlying conditions behind chronic sinusitis, like asthma and allergies.
• Avoid allergens (and irritants) such as animal dander, dust, pollen, smoke and mold that may trigger swelling in the sinuses.
• Quit smoking if you do smoke and avoid any secondhand smoke.
• Wash your hands thoroughly with soap and water.
• Rinse your nasal passages with saline solution
• Eat healthy foods, stay hydrated and exercise regularly to stay healthy overall.
• Use a humidifier to keep nasal tissues moist. Be sure to keep the humidifier clean and free of mold with regular, thorough cleaning.

See a doctor immediately if you have the following signs or symptoms, which could indicate a serious infection:

• Fever
• Swelling or redness around your eyes
• Severe headache
• Forehead swelling
• Confusion
• Double vision or other vision changes
• Stiff neck