Anaphylaxis is a severe, life-threatening allergic reaction that affects a number of different body systems. Anaphylaxis is most often caused by food allergy especially peanuts and tree nuts. Other causes of anaphylaxis include insect stings, latex and certain medications such as penicillin.
Symptoms of anaphylaxis can vary in severity. Sometimes, the symptoms are not life-threatening, but in some people it can be extreme and lead to death. Anaphylaxis symptoms usually occur rapidly and may include the following:
- Skin reactions, including hives along with itching, redness, and swelling
- Nose: sneezing; runny nose; stuffy nose (congestion)
- Mouth: Itching, swelling of the lips, tongue or mouth
- Throat: Difficulty swallowing, itching, swelling and throat tightness
- Respiratory symptoms that may be present include coughing, wheezing, shortness of breath, chest tightness, and chest pain
- Cardiac effects from anaphylaxis include weak pulse, passing out and shock
- Gastrointestinal symptoms may include abdominal cramps, vomiting and diarrhea
- Nervous system symptoms include dizziness or fainting
Your allergist will ask for a detailed medical history to identify the specific allergen that caused anaphylaxis. You may be tested for allergies with skin tests or blood tests to identify and confirm allergy triggers so that you can take steps to prevent future reactions.
An anaphylactic reaction can occur as:
- A single reaction that generally begins immediately after exposure to a trigger. This condition usually resolves within minutes to hours with or without any specific treatment and symptoms may not reoccur later relative to that episode.
- Two reactions: Here the person has a reaction that resolves and then recurs. The second reaction usually occurs within eight hours, but may occur up to 72 hours after the initial symptoms.
- A single, long-lasting reaction that persists for hours or even days after the initial reaction
If you or someone around you have an allergic reaction that might be anaphylaxis, call 911 for emergency medical services and seek immediate medical attention. An epinephrine auto-injector may be used if available to inject the medication into the thigh muscle. After injecting epinephrine you are positioned in a reclining position with the feet raised to help restore normal circulation. Your healthcare provider also may give secondary treatments with medications such as corticosteroids and antihistamines, supplemental oxygen therapy, and intravenous fluids.
As anaphylaxis is a life-threatening allergic reaction, if you experience these symptoms you should see a doctor who specializes in allergies and immunology.
Hives also called urticaria is a common skin disorder characterized by well defined, raised patches with a red margin that forms on the skin surface. It usually occurs due to allergy to certain foods or medicines. Hives can affect any part of the body but most commonly occur on the arms and legs and are often itchy.
Hives may be of two forms:
- Acute hives – condition lasts for less than 6 weeks.
- Chronic hives – condition lasts for more than 6 weeks.
Hives appear suddenly as a skin rash with smooth, raised reddish bumps called wheals, similar to an insect bite. The rash is very itchy. The redness of the rash seems to disappear when you apply pressure on it. This is referred to as blanching.
In most cases, the exact cause for acute urticaria remains unknown. Some possible causes for the acute form of urticaria are listed below.
- Infections – Fungal or viral infections of organ systems
- Insect bites
- Allergy to certain foods such as shellfish, fish, eggs, cheese, chocolate, nuts, berries, and tomatoes
- Medicines such as penicillins, antihistamines, and non-steroidal anti-inflammatory drugs (NSAIDs),sleeping pills, blood pressure medications
- Environmental factors – pollens, chemicals, plants, animal danders, dust, and molds
- Allergy to latex products
- Exposure to extremes of cold or heat
- Emotional stress
Chronic Urticaria may be caused by all the factors which cause the acute form. In addition, other causes can include autoimmune disorders, emotional stress, heat, exercise, and chronic illnesses such as thyroid diseases, cancer and lupus.
Recurrent urticaria can occur because of chronic sun exposure, exercise and stress.
Your doctor will take a complete medical history and perform a physical examination of the rash. A previous history of allergy will suggest hives. Your doctor may order basic laboratory tests such as complete blood count and erythrocyte sedimentation rate (ESR) to confirm the condition. A punch biopsy will be done if the lesion persists for more than 24 hours accompanied by intense pain and itching.
Medications that your doctor may prescribe include:
- H1-receptor antagonists (antihistamines): Acute forms of urticaria will be treated with H1 antihistamine drugs. Some of the common H1 antihistamines are Hydroxyzine hydrochloride (Atarax®, Vistaril®), Diphenhydramine (Benadryl®, Benylin®, Diphen®).
- H2 antihistamines such as Famotidine (Pepcid®), Ranitidine (Zantac®) Cimetidine (Tagamet®) will be added in persistent cases.
- Chronic forms of urticaria are treated with glucocorticosteroids. A tricyclic antidepressant, doxepin, also helps in persistent cases.
- Skin creams – Doxepin cream 5% (Zonalon®) or capsaicin may also be recommended.
Some of these preventive methods can help prevent the occurrence of hives.
- Avoid taking over-the-counter medication such as cold and sinus tablets and decongestants, medication for headaches, cough medicines, lozenges, mouth washes, laxatives, douches, hemorrhoid medications and suppositories, vaginal suppositories and medications, vitamins and tonic water
- Avoid exposure to allergic substances (medication, food, environmental factors).
- Avoid wearing tight clothes.
- Avoid hot baths or showers.
- Avoid vigorously rubbing your skin with a towel after a bath instead just pat your skin dry.
- Apply moisturizer to your skin frequently to prevent dryness of skin as it often worsens hives.
- Manage physical and emotional stress by relaxation methods and meditation.
Urticaria affecting deeper layers of the skin is referred to as angioedema. Angioedema usually involves the skin around the eyes, cheeks or lips. However, it can also involve the hands, feet, genitals and the mucosa of the throat and bowel in severe cases. Angioedema and urticaria can occur disjointedly or at the same time.
The symptoms of angioedema include:
- Swelling of the skin
- Pain and local rise of temperature of the affected region
- Discrete welts
- In severe cases, patients may experience difficulty in breathing or swallowing due to swelling of the inner lining of the throat and air tubes
- Patients may also experience distortion of vision secondary to swelling of the conjunctiva
Types of angioedema
The four major types of angioedema include:
- Allergic angioedema- caused due to allergic reactions, such as reaction to ingestion of peanuts
- Idiopathic angioedema- the underlying cause is not known; certain factors such as stress or infection may be involved
- Drug-induced angioedema- caused secondary to a reaction to some medications
- Hereditary angioedema- caused due to faulty genes inherited from their parents. This form of angioedema is not associated with urticaria.
Angioedema may be caused due to the allergic reaction resulting in the release of histamine and other chemicals into the bloodstream. In a majority of the cases the cause of angioedema is not known. The following are the common causes of angioedema:
- Allergies to food, medication, cosmetic, soaps, detergents and pet dander
- Insect stings and bites
- Emotional and physical stress
- Exposure to physical agents such as sunlight, heat, cold and pressure
- Infections and certain diseases such as lupus, lymphoma and leukemia
The diagnosis of angioedema involves the physical examination of the skin. The doctor will inquire about exposure to any irritating substance. In a few cases, blood tests may also be conducted. Physical examination may also reveal abnormal breath sounds such as stridor.
Mild angioedema may not require any treatment. In moderate to severe cases medications may be required to relieve the symptoms. Cold compresses can help relieve pain. The other approaches used for the management of angioedema are listed below:
- In case of allergic angioedema eliminate the exposure to the allergen which can include food, medication, contact allergen etc.
- For drug induced angioedema, the offending medication can be substituted by an alternative medication.
- Antihistamines provide symptomatic relief
- A prophylactic approach is recommended in hereditary angioedema as it does not respond well to the commonly used medications.
- Adrenaline and steroid shot may be used in severe cases
- In the case of severe breathing difficulty, the patient may be intubated.
In cases of severe angioedema that does not respond to treatment contact your physician immediately.