Related diseases

In this section we will differentiate what is an ALLERGY (immunological hypersensitivity) from INTOLERANCE (non-immunological hypersensitivity) and we will focus on two types of allergic reactions that are related with lactose intolerance (LI): Celiac disease (CD), cow’s milk protein allergy (CMPA), Galactosemia (GL) and Hereditary fructose intolerance (HFI), and you will find the associations where to go if you want to know more.

Celiac disease CD
It affects 1% of the adult population and is permanent for life
Celiac disease is an immune-based chronic systemic disorder caused by gluten intake in people with a genetic predisposition. Celiac disease causes an inflammatory lesion and atrophy of the intestinal villi, causing a problem of malabsorption of nutrients and deficit of minerals such as iron, calcium, vitamins and fats. This deficit will consequently cause systemic problems: rheumatological, endocrinological, neurological, dermatological or reproductive. Gluten is a protein present in the grains of cereals wheat, barley, rye and oats, as well as in its natural and hybrid varieties, such as spelled and kamut (old varieties of wheat), triticale (hybrid of wheat and rye) and tritordeum (hybrid of wheat and barley). It is estimated that over 50% of celiac sufferers secondary lactose intolerance in their previous diagnosis phase. Lactase enzyme is one of the first enzymes to disappear from intestinal villi when damaged. When the diagnosed celiac begins the strict diet of exclusion, it recovers its villi and the enzyme lactase, so that a high percentage of celiacs recover and stop suffering from lactose intolerance as their villi and digestive enzymes recover.


Cow milk’s protein allergy CMPA
It affects 2% of the child population and evolves and may disappear
Cow milk protein allergy APLV occurs when an individual, after ingesting milk protein (basically casein) manifests an adverse response with symptoms and in that reaction there is a proven immune mechanism. After exposure to the allergen, the subject is sensitized and produces specific antibodies for some protein fractions of milk, these are the so-called specific immunoglobulins and IgE. In the second exposure, the antigen binds to IgE and a response of different magnitude is triggered, it is the allergic reaction. Symptoms often become apparent at the first apparent contact with milk, such as bottle feeding. Even sometimes during breastfeeding, symptoms are seen due to the passage of protein through the milk secretion, such as the exacerbation of dermatitis. In the case of IgE-mediated immediate hypersensitivity milk protein allergy, the clinic appears in less than 60 minutes from intake, and the severity of the symptoms of milk allergy is highly variable depending on the degree of sensitization and the amount ingested . In addition to ingestion, milk can produce symptoms by direct or indirect skin contact, kissing, rubbing, vomiting and also respiratory symptoms by inhalation. In order of frequency, the most common are skin symptoms, followed by digestive or association of both, and finally respiratory and anaphylaxis. As in other food allergies, the allergological study consists of the preparation of a clinical history, prick-test, blood determination of specific IgE and controlled exposure. Once the diagnosis is established, periodic reviews are performed in which the allergist evaluates the evolution. In the case of CMPA, as the onset usually occurs in the first semester of life, it is usual to perform a review six months after the initial picture. From then on and until 4 years of age, in most cases, the patient is reviewed annually, repeating the allergic study. CMPA, although it has the same food origin, has nothing to do with lactose intolerance.

Galactosemia GL

It affects 1 among 45,000 births (Rare disease)
The term “galactosemia” means galactose in the blood and results from an impaired ability to metabolize galactose. Galactosemia is an inborn error of metabolism. It is also considered a minority or rare disease, given the low prevalence. Galactose is mainly present in milk and dairy products, where it is present in the form of lactose. After ingestion, lactose breaks down into the two sugars galactose and glucose. Galactose is very important for the newborn, in that it represents 20% of the energy source. To be used by the body, galactose must first be converted to glucose-1-phosphate and UDP-galactose via Leloir (figure). Poor activity of any of the enzymes in the Leloir pathway leads to galactosemia. The most common is classical galactosemia (or type I galactosemia), which results from impaired GALT activity, and occurs at a frequency of 1: 16,000-60,000. Patients begin to develop symptoms a few days after birth that are resolved by replacing milk containing galactose with milk of a specific formula, usually soy. Babies with classic galactosemia, unable to metabolize galactose, suffer an accumulation of it in the body, so that it produces damage to organs such as the kidneys, liver, central nervous system or sight, among others. Unfortunately, early detection and prompt implementation of dietary treatment fail to prevent long-term complications, such as cognitive and ovarian abnormalities. PDF Explanatory

The other types of galactosemia
· Type II galactosemia results from GALK deficiency. The main clinical feature is cataracts in the neonatal period, which can be resolved or prevented with a galactose-restricted diet. Conclusive evidence indicating long-term complications is lacking.
· Type III galactosemia is the result of altered GALE activity and is described as a more benign form of periphery than the potentially fatal generalized form. Generalized neonatal presentation is adequate due to diet, but, in the medium and long term, it is ineffective as long-term complications develop.
Type IV galactosemia was first described in 2018 in several patients with a GALM defect.
There is also the so-called Galactosemia Duarte. In this case we find a higher enzymatic activity, and sometimes it can be asymptomatic.


Hereditary fructose intolerance HFI
It affects 1-9/ among 100.000 (Rare disease)
Hereditary fructose intolerance (HFI) is a rare autosomal recessive metabolic disease where there is a deficiency of the enzyme “ALDOLASA B”, an enzyme responsible for the metabolism of fructose (in the liver, kidneys and intestine). Its diagnosis is made by genetic testing (looking for genetic mutations in the gene that codes for the enzyme). Fructose is found naturally in fruits and many vegetables, as monosaccharide or in the form of sucrose (fructose-glucose disaccharide), in addition to the contraindication of other polyalcohols and / or sweeteners such as sorbitol (which is metabolized to fructose), maltitol, lactitol, isomaltitol, tagatose, etc. Consumption of any source of fructose in these patients can cause severe acute poisoning with nausea, vomiting, sweating, lethargy, coma, shock, dehydration, severe liver dysfunction and / or hypoglycemia. In addition, the consumption of small amounts continuously (due to poor adherence to the diet) can cause recurrent vomiting, hepatomegaly with different degrees of liver dysfunction, edema and / or ascites and failure to thrive. The only treatment currently available is the elimination of all sources of fructose from the diet (below 40 mg of fructose / kg / day) strictly and permanently throughout life, in this case having a good prognosis at long term. But this premise in practice can be difficult because there is little information on the amount of contraindicated sugars present in many foods (the nutritional composition only requires the declaration of sugars as a whole) and many published food tables have incomplete information or contradictory. It is very important not to be confused with fructose malabsorption (misnamed fructose intolerance, whose diagnosis is made by the expired hydrogen test), since the latter is due to a problem in the absorption of this sugar, mainly producing gastrointestinal symptoms (diarrhea, flatulence, etc.), although the rest of the symptoms will depend on the main cause of this malabsorption.