Lactation Anaphylaxis

Information found on this page is strictly for educational purposes. If you believe you have had or are having an allergic reaction related to milk removal, please call your healthcare provider or emergency services.

Here is the article I published with my colleague, Dixie Whetsell, in the European Lactation Consultant Association’s magazine, ELACTA.

Click here to view the information below in Russian.

What is lactation anaphylaxis?

Lactation anaphylaxis (LA), or breastfeeding anaphylaxis, is an allergic response to the milk ejection reflex (MER) or let down. The reaction usually occurs within minutes of latching, pumping, or hand expressing but can also occur after 30+ minutes.

It is important to know that with the right medical treatment most parents with this medical condition will be able to continue to breast or chest feed their children.

What causes lactation anaphylaxis?

The exact cause is unknown. The most common explanation is that the hormonal changes that occur in a lactating parent may trigger immune cells known as mast cells to release chemicals which can trigger an allergic reaction.

Why do some parents experience this while most do not? The number of mast cells in a person's body and how reactive those cells are may make some people more likely to have a reaction than others.

A bit about mast cells

Everybody has mast cells. During pregnancy, they multiply and are kept calm by the large amount progesterone (pregnancy hormone) circulating in the birther’s body.

Mast cells contain tiny chemicals called mediators. There are a lot of different kinds of mediators inside of a mast cell. Different mediators play different roles in the immune system. Histamine is one type of mediator. It causes the allergic symptoms listed below.

After birth, progesterone levels decrease quickly and so does its calming nature. The drop in progesterone levels is a big change for a person’s body. Not only does the change allow mast cells to release their mediators, it also allows milk to increase in amount and change its ingredients. With each latch/pump, hormones change to allow milk to flow rapidly (let down).

In some parents, these simultaneous changes may allow a repeated allergy response with each milk expression.

When does L.A. typically occur?

Most commonly, the more serious symptoms become noticeable about 3-4 days after birth when there is a large change in hormones and milk production rapidly increases in volume.

Symptoms usually start within minutes of latching or pumping but can also have a delayed reaction of 30+ min after latching or pumping.

Symptoms often start out mild and may not be associated with milk expression because they are slight. With each let down, symptoms may become more serious.

Symptoms

Similar to any kind of anaphylaxis, symptoms can vary. Symptoms that are typically associated with anaphylaxis are:

• Hives, rash

• Shortness of breath/difficulty breathing

• Wheezing

• Cough

• Hoarse voice

• Nausea, vomiting, and/or diarrhea; abdominal pain

• Sweating; clammy hands

• Facial swelling

*This is not a complete list. If you are concerned about your health, contact your healthcare provider or go to the closest emergency room.

What is the treatment for L.A.?

When a parent is experiencing the most severe symptoms of LA, the medications given in the hospital are the same as those given to anyone with anaphylaxis. They do not change because the person is lactating.

Epinephrine, steroids, and famotidine are common anaphylaxis medications and should not be withheld due to the concern of impacting the baby. Often an antihistamine such as Benadryl is also given. These medications may temporarily decrease milk supply.

The parent does not need to pump and dump after treatment with these particular medications as the milk is safe for the baby to consume. If you are unsure if any medication you take is safe for your baby, pump and save your milk until you can speak with a lactation consultant about the medication’s safety. Label the milk with the date and time of pumping, and also the date and time of the medications you took prior to pumping.

After the most severe symptoms are treated, many people continue breast or chest feeding while taking a daily antihistamine such as loratadine (Claritin) or cetirizine (Zyrtec).

Can I continue to breastfeed, chestfeed, or express milk?

Yes! With the right medications you can continue to breastfeed. If you have a desire to breastfeed your baby, speak up to the medical team about your feeding goals.

You may be able to stop the daily medications after your body stops reacting to let down.

Some parents may decide they don't want to continue to breast or chest feed because of the frightening experience of anaphylaxis. It is your decision to make and only you can make the best choice for your family.

What to do

If you think you have LA, go to the emergency room at your local hospital. Symptoms can progress quickly and are unpredictable.

Bring a breast pump with you and request lactation help if you need it in the hospital. Many hospitals have International Board Certified Lactation Consultants (IBCLC) available to help you.

If you have to stay in the hospital overnight, ask if you can stay in the postpartum unit. This unit will have the right supplies and knowledgeable staff to care for you and your baby if they are able to join you.

Who to contact

Go to the emergency room now if you are currently experiencing symptoms of anaphylaxis.

If your baby is less than 8 weeks old, contact your pregnancy care provider and tell them what is happening. If your baby is more than 8 weeks old, your primary healthcare provider may be a better person to call than your pregnancy care provider.

You may want to contact an IBCLC for lactation support. In addition, you may want to talk to a physician who specializes in Breastfeeding Medicine.

If you have questions, feel free to contact me.

References

If you’re looking for more information on lactation anaphylaxis, these are the references my colleague, Dixie Whetsell, MS, IBCLC, and I have collected. They are medical studies, journals, and websites and are geared toward medical professionals.

Updated October 2023