Lactose intolerance does not cause hives but an allergic reaction to dairy does. MayoClinic.com states that a milk allergy and lactose intolerance are commonly confused conditions because they can cause similar symptoms. If you develop hives after consuming dairy products and you've been thinking it was related to lactose intolerance, you need to see an allergist. It is possible to have both conditions, but hives are always a sign of an allergic reaction, not intolerance.
Lactose Intolerance
Lactose intolerance is a digestive condition that makes it difficulty to digest the sugar found in diary products. If you're lactose intolerant, your digestive system doesn't create lactase, the enzyme that breaks lactose down into more simple sugars, according to the National Digestive Diseases Information Clearinghouse. Lacking lactase will lead to the inability of the body to absorb the sugar. The undigested lactose goes throughout the digestive system until it enters the colon. In the colon, it interacts with bacterium, which leads to common symptoms, such as gas, bloating, diarrhea and cramping.
Milk Allergy
A milk allergy is a very different condition in comparison with lactose intolerance. Lactose intolerance is caused by a digestive defect, while a milk allergy is the result of an overreaction of the immune system. Milk allergies can cause life-threatening symptoms to form, while lactose intolerance does not cause any permanent damage. During an allergic reaction to milk, the immune system mistakes the proteins in the product as dangerous and begins to defend the body by producing antibodies and histamine. These chemicals cause inflammation, irritation and swelling in soft tissues throughout the body.
Hives
Hives are one of the most common food allergy symptoms that can form within minutes of consuming dairy products. Hives are triggered by increased amounts of histamine in the skin. Hives develop as welts in clusters in different shapes and sizes and can migrate from area of the body to another, according to PubMed Health. Hives commonly first develop on the face, arms or legs. Hives may be a sign of a severe allergic reaction that could be life-threatening.
Anaphylaxis
Anaphylaxis is a severe allergic reaction, commonly associated with food allergies. Hives is a common symptom of anaphylaxis accompanied with other symptoms, such as the inability to breathe, lightheadedness, an increased heart rate, dizziness, a metallic taste in your mouth, a drop in blood pressure, throat swelling and facial swelling. Call 911 if you develop one or more of these symptoms.
