Distinguishing HAE From Other Medical Problems

HAE is caused by a problem in a person’s genetic code for a single protein, known as C1-INH.

As you may remember from high school biology, each person receives half their genetic code from their mother and half from their father. In some diseases, such as cystic fibrosis or sickle cell anemia, a child must receive the abnormal, disease-causing gene from both parents. Biologists call these autosomal (AW toe ZOAM ul) recessive genes. Unfortunately, HAE may mimic other types of medical conditions. For example, it may be mistaken for an allergic reaction. However, there are some clues that help physicians identify HAE and distinguish it from other medical problems.

How do you know if you have HAE? The ABCs of HAE can identify whether or not your symptoms are suspicious of HAE.

Again and Again
HAE attacks tend to occur again and again. These recurrent attacks may have begun in childhood and may have worsened over the years.

Body Part
HAE can occur in different body parts during different attacks. Additionally, swelling can move from one site to another. For example, a facial attack can move to the throat. Physicians refer to these as migratory attacks, and these travelling attacks tend to last several days longer than attacks of edema that affect only one site. The most common sites for attacks are:

• Extremities (hands, feet, arms, legs)
• Intestines (abdomen)
• Face
• Genitals
• Larynx or voice box

Furthermore, attacks may affect only one side of the body. For example, only one hand or one foot may be swollen at a time. In allergic reactions, both sides of the body tend to be equally involved.

Conjunctiva
The conjunctiva is the membrane covering the eyeball and under the surface of the eyelid. In allergic reactions, the eyes tend to be watery and itchy. Although people with HAE may also have allergies, itchy, watery eyes are not a symptom of an HAE attack.

Drugs
Allergic reactions to foods, drugs, or insect bites tend to respond quickly and dramatically to drugs, such as epinephrine, antihistamines, and corticosteroids. On their own, HAE attacks spontaneously improve over time, and it may even appear that these anti-allergy drugs are effective in HAE attacks. Even if the medications appear to work, they will lack the dramatic response seen in an allergic reaction.

Edema (swelling)
Although the location of an HAE attack can vary, it always includes swelling, also known as edema (EH deem uh). Doctors call this type of edema, non-pitting edema, because if you use your index finger to press on the area, the skin bounces back and does not leave an indentation or pit.

Family history
Although it is possible to be the first person in your family to have a change in the gene that causes HAE, in most cases other family members also have had similar attacks. In a recent survey of people with HAE, about 85% of the respondents were able to identify other family members who had HAE.

Even if no one in your family has been diagnosed with HAE, speak with family members (parents, aunts, uncles, etc.) to see if they have had swelling episodes that sound as though they might be related to HAE. For example, a grandparent, aunt, or uncle who “choked to death” may have had a laryngeal attack.

Gastrointestinal surgery
When people with HAE are not properly diagnosed, they may undergo unnecessary abdominal surgeries. Some may have had unnecessary surgeries to remove their appendix or have undergone exploratory laparoscopies (small cameras inserted into the abdomen) in search of a cause for their abdominal pain.

If your symptoms are suspicious of HAE, an HAE expert can order the appropriate blood tests to confirm the diagnosis.