Medication

Sodium cromolyn is not absorbed into the body and likely works by stabilizing mast cells where it is applied (i.e., digestive system, eyes, nose, etc.).

Taken by mouth

Sodium cromolyn is available in liquid or capsules and is taken before meals.

Eye drops

Nasal spray

Inhalation (nebulizer)

Taken by mouth

Ketotifen is available as a syrup or tablet. The timing is not related to meals. It is absorbed into the body and works as a mast cell stabilizer and an H1 antihistamine (see below for an explanation). Prevention of allergic asthma is the most common use.

Eye Drops

Used to treat allergic conjunctivitis (allergic reaction in the eye).

Antihistamine medication blocks the effect of histamine. Mast cells are like tiny balloons filled with inflammatory chemicals – such as histamine. There are mast cells throughout the body, especially where the body meets the outside world (e.g., digestive, respiratory, urogenital systems & skin). Inflammatory chemicals leak out of mast cells (called mast cell activation or degranulation) primarily during an immune response (e.g., defending the body against germs) or allergic reaction. Histamine is the most well-known inflammatory chemical. Histamine moves through the body in the blood. The organs have four different receptors for histamine. A very simplified summary is:

• When histamine binds to H1 receptors: 1) blood vessels dilate and become leaky (fluid leaks from blood vessels into surrounding tissue, contributing to tissue swelling) 2) nerves tingle (itching), 3) respiratory tubes contract (difficulty breathing) 4) mucus production increases. 5) Etc.
• H2 receptor stimulation increases stomach acid production and may lead to digestive upset, such as heartburn.
• The effect of H3 & H4 receptor stimulation is not well understood, but probably affects the central nervous system.

Antihistamine medications bind to the receptors, which prevents histamine from binding and changing how the organ functions (e.g., blocking the H1 receptors will reduce the blood vessel dilation).  Also, mast cells have histamine receptors. Stimulation of these receptors can lead to mast cell activation, so antihistamine medications could also be classified as mast cell stabilizers.

There are many reports on the internet that antihistamine medications cause the body to produce more histamine. To my knowledge, there is no research to prove or disprove this. However, if this were true, the side effect of H1 antihistamines would be increased stomach ulcers, and reflux (i.e., increased acid) and the side effect of H2 antihistamines would be increased allergic symptoms. These are not common side effects listed with these medications.

H1 Antihistamines (block H1 receptors)

Taken by mouth:

First Generation: Diphenhydramine was the first antihistamine developed. It is the fastest acting and is often used to treat acute allergic reactions (in conjunction with epinephrine, see below). Diphenhydramine is in many cold medications, but I’ve only listed the medications which are 100% diphenhydramine.

Second Generation: These antihistamines were developed later and had fewer side effects (especially less sedation). Each of these medications is a different chemical and binds to H1 receptors differently. Therefore, the side effects and effectiveness can vary between individuals. Work with your doctor and pharmacist to experiment and find the best one for you.

Eye drops:

Nasal Spray:

H2 Antihistamines (block H2 receptors)

These chemicals bind to H2 receptors. They are commonly used to treat ulcers and gastroesophageal reflux.

Leukotrienes are a group of inflammatory chemicals produced during mast cell activation, so the effects are more delayed compared with histamine (because histamine is stored in mast cells and is released immediately upon activation). Leukotrienes have diverse effects throughout the body, including swelling and narrowing of the respiratory tubes. The most common use of leukotriene inhibitors is asthma and season allergies.

Prostaglandins are another group of inflammatory chemicals produced during mast cell activation. Non-steroidal anti-inflammatory medications (NSAID’s) block the enzymes which produce prostaglandins. Several different types are listed below. Aspirin is the most commonly prescribed NSAID in mast cell disease . In addition to reducing inflammation, NSAID medications reduce pain, and some also reduce fevers.

Corticosteroids reduce inflammation by suppressing the immune system. They are a synthetic version of cortisol, which is a hormone produced by the immune system. In most cases, they are used for short term treatment.

Taken by mouth

Corticosteroids are absorbed into the body and are used to reduce inflammation throughout the body.

Creams

Reduces inflammatory skin rashes.

Nasal sprays

Reduces inflammation in the nasal passages, sinuses and surrounding tissues.

Inhaled through the mouth

Eye drops

Reduces inflammation in the eyes, eye lids and surrounding tissue.

An epinephrine auto-injector may be prescribed if a patient has experienced anaphylactic symptoms. Epinephrine (also called adrenaline) is a hormone that is released in the body when we are scared (flight or fright syndrome). It can temporarily reduce anaphylactic symptoms, by opening the airways, improving blood pressure and increasing the heart rate.