Lactose intolerance results from the inability to digest lactose, which is the sugar in milk. If you have discomfort -- including eczema -- when you drink milk, you may think you're lactose intolerant. However, eczema isn't a symptom of lactose intolerance, but is instead an indication that you may have a milk allergy.
Lactose
Lactose is milk sugar, and is an energy-providing compound that most humans can use without any difficulty. The sugar consists of two smaller sugar units, called glucose and galactose, that are chemically bonded together. To absorb the small sugars into the bloodstream, you have to break the bond between them, explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry." The enzyme lactase helps with this reaction, and if you don't produce enough lactase you'll have lactose intolerance.
Lactose Intolerance
Lactose intolerance is characterized by digestive discomfort when you consume lactose-containing foods. You may have gas, bloating, cramping, or diarrhea, explains MayoClinic.com. These result from lactose passing undigested into the lower gastrointestinal tract. There, bacteria break down the lactose, and as a byproduct of this reaction, produce large quantities of gas. Lactose intolerance isn't an allergy, and doesn't involve any activation of the immune system -- it's merely an inability to digest a component of food, and has purely digestive symptoms.
Eczema
Eczema results from an irritation of the skin, sometimes by something you've eaten to which you're allergic, and sometimes by something with which you've come in contact. If you experience eczema upon consuming milk, it's not an indicator of lactose intolerance, but is instead an indicator of a milk allergy, explains MayoClinic.com. Milk allergies are potentially much more severe than lactose intolerance, and can even be life threatening under some circumstances.
What To Do
If you have any symptoms that trouble you, whether they're as mild as a bit of stomach upset or as serious as eczema, when you consume milk, you should talk to your doctor. Your doctor can test your body's reaction to milk and can determine whether you have lactose intolerance, an allergy, both, or neither. You can take lactase supplements to avoid symptoms of lactose intolerance, but simply avoid milk if you have an allergy.
