Infusion Therapies in Allergy and Immunology

There are disease states where medications taken by mouth do not offer enough benefit in either relieving symptoms, stopping the progression of a condition, or preventing complications of a disease. In these instances, medications may need to be administered by means of the parenteral route, such as using a needle or catheter to infuse the medication.

The 2 ways that the administration of medications via the parenteral route can be accomplished include:

1. Intravenous route: A needle or catheter is inserted into a vein and the medication is infused. A peripheral vein in the arms or legs is most commonly used. Rarely a “central” deeply situated vein may need to be catheterized for long-term medication administration.

2. Subcutaneous route: A needle or catheter is inserted just under the skin and the medication is infused. The liquid medication is gradually absorbed into the blood stream from the surrounding “subcutaneous” space.

One of the most common medications used by allergists/immunologists like the one’s at Black & Kletz Allergy are immunoglobulins (i.e., antibodies) which are given by infusion therapy to treat diseases where one’s own immune system is unable to manufacture antibodies to fight infections. These diseases are called primary immunodeficiency diseases (PIDD). Untreated, the patient experiences frequent, severe, and sometimes life-threatening infections. These infections can be prevented by replenishing the body with “outside” antibodies (i.e., antibodies collected from healthy donors) through either intravenous or subcutaneous infusions. In some instances, the therapy is begun as intravenous therapy and then it may be transitioned to the subcutaneous route.


The immunoglobulins that are used to treat these conditions are extracted from the plasma of healthy blood donors. They are usually pooled from thousands of donors, concentrated, and purified. They are treated to prevent transmission of blood borne diseases and then packaged in sterile conditions.


Intravenous infusions generally take approximately 3 to 4 hours each time to infuse. Subcutaneous infusions, on the other hand, can take up to 6 hours to get to the desired place because the solution is gradually absorbed from the site.


Intravenous infusions are usually given once every 4 weeks, whereas the interval between subcutaneous infusions can vary between 1 and 4 weeks depending on the specific product.

Intravenous infusions usually involve 1 needle stick in order to insert a catheter into the vein, whereas subcutaneous infusions may need 2 to 4 different sites (over the abdomen, thighs, etc.) depending on the volume of the solution that needs to be injected.


Patients can be trained to infuse the medications at home by using electric infusion pumps. The infusions are not usually painful. In complex situations, the treatments are given either in doctor’s offices or in infusion centers located in hospitals or free-standing infusion centers.


Intravenous infusions rarely cause systemic side effects. Headache is a commonly reported side effect. Some patients also experience chills and sweating during infusions. These side effects can often be mitigated by slowing down the rate of infusions. After the infusion is completed, some patients may experience fatigue and achiness for a day or two. These side effects can sometimes be prevented or minimized by being premedicated prior to the infusions.

Subcutaneous infusions usually cause fewer systemic side effects than intravenous infusions but they still may cause local reactions such as redness, swelling, and/or pain at the site of administration.


The doses of immunoglobulin infusions are adjusted based on the “trough” or lowest levels (i.e., immediately before the next dose) for IgG antibodies. The goal is to constantly maintain these IgG levels in the normal range.

The frequency and severity of the infections are also closely monitored to assess the effectiveness of the antibody replacement therapy.


In addition to immunoglobulins, other therapeutic agents such as antibiotics, corticosteroids, and biologicals can also be administered either intravenously or subcutaneously for conditions treated by allergists/immunologists. There are a multitude of biologicals on the market and more are becoming available to treat a slew of allergic or immunological conditions such as asthma, eczema (i.e., atopic dermatitis), chronic hives (i.e., urticaria), and chronic rhinitis with nasal polyps. The treatment of food allergies may be another allergic condition in which biologicals may be used in the future depending on the results from ongoing research.

The board certified allergists at Black & Kletz Allergy have treated numerous patients with conditions requiring treatment by the intravenous and subcutaneous routes in the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 50 years. We treat both children and adults and we have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. All 3 offices of Black & Kletz Allergy have on-site parking and the Washington, DC and McLean, VA offices are Metro accessible. There is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. If you would like to be seen for any allergy or immunology condition, please call us to make an appointment or alternatively, you can click Request an Appointment and we will respond to you within 24 hours of the next business day. Black & Kletz Allergy is proud to continue to provide high quality allergy, asthma, and immunology care to the Washington, DC metropolitan area.