Angioedema is similar to hives but these raised swellings are deeper than merely on the surface of the skin, but in the deeper layers. Angioedema is an allergic reaction. Some of the causes for angioedema are certain foods like eggs, berries and nuts, animal dander, medicine allergies and pollen. In angioedema, there is rapid swelling just below the surface of the skin; usualy around the eyes and lips. These welts can be painful and may be accompanied by breathing difficulties and abdominal cramps. When they occur in the airways, the situation can be a medical emergency. Typically antihistamines or anti-inflammatory medicines are prescribed.
Heriditary angioedema: Genetically passed
Allergic angioedema: Reaction to an allergen
Drug-induced angioedema: Side effect to a medication
Idiopathic angioedema: Without any known trigger.
Hereditary Angioedema is a rare genetic condition that causes episodes of edema (swelling) in various parts of the body intermittently. The main target areas are usually limbs, throat, lips, eyelids and abdomen. These attacks may or may not occur frequently. But if left untreated, it can be life-threatening. However, the patient feels completely normal in between the attacks. This condition occurs as result of either deficiency or improper function of protein C1 esterase inhibitor (C1-INH) in plasma. C1 esterase inhibitor is responsible for regulating the production of a hormone called bradykinin. Higher amount of bradykinin is produced in the body when protein C1 esterase inhibitor does not function normally. Increased bradykinin hormone levels leak the fluid from blood vessels into the body tissues resulting in edema.
There are three different types of Hereditary Angioedema.
In Type I HAE, blood contains low level of C1 esterase leading to excess production of bradykinin, resulting in swelling attack.
With Type II HAE, blood contains normal levels of protein C1 esterase inhibitor but fails to function normally leading to to inflammation and swelling episodes.
Type III HAE is very rare, and isn't associated with functioning of C1 esterase inhibitor.
HAE is caused due to the mutations inherited from a parent. The gene is dominant, which means one abnormal copy is enough to cause HAE. However, one fourth of the Hereditary angioedema cases aren't inherited. They occur from spontaneous mutation that takes place at conception.
Symptoms of Hereditary Angioedema
Most often Hereditary Angioedema manifests into cutaneous swelling, on the face, hands and extremities. Though not common, it also causes abdominal swelling and the swelling of airway passage in few cases. The disease may become potentially life-threatening when upper respiratory system of the patient is attacked - asphyxiation. Early suspicion, recognition and treatment of this condition are important.
Certain triggers have been identified that leads to the episodes of swelling. Try and identify your triggers - certain foods, environmental factors, medications, anxiety or certain physical activities. They include physical injury, medical or dental procedures, psychological stress, menstruation, pregnancy, infections and certain medications such as exogenous estrogen (OCP) and angiotensin-converting enzyme inhibitors. Some patients do take preventive medication, after consulting their doctor. After a bout of HAE, take rest and hydrate yourself. Log your attacks.
Diagnosis and treatment
Since edema can indicate host of other conditions, it is difficult to diagnose HAE with clinical symptoms alone. Taking note of family history of swelling attacks and the frequency of attacks in the patient himself should be the starting point to diagnosis. Further, laboratory analysis of blood samples for C1, C2 and C4 levels along with genetic testing is required to confirm Hereditary Angioedema.
Currently there is no cure for Hereditary angioedema. However medicines are available for treating patients with acute HAE attacks to address the symptoms during attacks. HAE is also treated with prophylactic therapy (preventative HAE treatment).
Hives or urticaria is red itchy spots that appear on the skin, their bump-like appearance being the reason for the given name. They usually occur when a person develops an allergy to a drug, insect sting or food item. Infections or stress may also lead to the condition due to the release of certain chemicals such as histamine or mast in the body. Histamine is released when the body is in contact with toxins or pollen. This is a common condition that usually occurs in individuals who are more prone to allergies.
Normally hives lasts about one to two days and in this duration it may change rapidly in size and location by the hour. It may appear to have completed receded, only to quickly reappear in another spot. Hives may be accompanied by a deeper swelling known as angioedema and may also appear in mucous membranes, the eyes and lips.
Chronic urticaria lasts about six weeks and in about 80% of the cases cannot be traced to any allergic reaction. Urticaria may cause difficulty in breathing and shock but this occurs only in rare cases and hives hardly leads to life threatening situations. Hives affects 15 to 20% of the population at some time in the course of their lives. Acute hives in children may be caused due to a viral infection.
It is said that having hives may lead to stress, but stress does not lead to hives. However some studies show that emotional stress may cause hives, as do extreme hot or cold weather conditions. Chronic stress and tension may cause hives, so it is important to find ways to relax and take some time off your normal routine. Stress affects the immune system and may indirectly lead to hives especially when it persists for a long period of time. Stress is known to affect the hormonal balance and the body chemistry leading to hives.
Hives usually recedes by itself without any serious implications. In severe conditions, drugs or injections may be prescribed. Only in rare cases where a swelling blocks the airway and prevents the person from breathing properly, would it be described as an emergency.
Bibliography / Reference
Collection of Pages - Last revised Date: February 22, 2018