Information of interest

Cow´s milk allergy

Cow´s milk allergy 1024 576 Jaritzy Negrín González

Cow’s milk is the food that most frequently causes food allergies in children under 1 year of age.

Why is food allergy more common?

Because cow’s milk proteins are one of the first antigens (allergens) that the child comes into contact with in their diet.

How is cow’s milk composed?

Cow’s milk is composed of proteins that are classified into two groups: casein (80%) and whey proteins (20%). The main components of whey proteins are betalactoglobulins and alphalactalbumin.

These proteins are the allergens that trigger the production of antibodies.

Why is it called cow’s milk protein allergy?

These are clinical signs of an adverse reaction to cow’s milk with a proven immunological mechanism: reactions mediated by IgE antibodies or by another immunological mechanism (non-IgE). It is important to differentiate between both types because they present different pathophysiology, symptoms and evolution.

When do symptoms start?

It is variable, it can start during the period of exclusive breastfeeding but most cases begin when starting artificial breastfeeding after the period of breastfeeding. It begins in the vast majority of cases the first year of life with a maximum peak between 3-4 months of age. Exceptionally they can start after the second year of life.

What are the symptoms?

In 75-92% of children with cow’s milk protein allergy may have more than one symptom:

  1. Skin symptoms: this is the most common clinical condition characterized by erythema (redness), urticaria (wheal-like lesions) and angioedema (swelling). Initially it may appear in the perioral area and may or may not generalize to other parts of the body. Sometimes infants may have as their first and only clinical manifestation the refusal of cow’s milk bottle feedings or breastfeeding.
  2. Digestive symptoms: may be vomiting and diarrhea. In 30% of cases they are associated with other symptoms. Vomiting is a common clinical manifestation in IgE-mediated allergy.
  3. Respiratory symptoms: wheezing, cough, rhinoconjunctivitis are rare as an isolated symptom in the infant.
  4. Anaphylaxis: may be the debut in infants in 1% of cases. It is common in older children or adolescents with persistent cow’s milk allergy after accidental contact or transgression.

How is the allergy study carried out?

Allergy tests are indicated by making a personalized evaluation of each patient according to their clinical picture.

Initially in the consultation with your allergy specialist, a medical history is taken, detailed anamnesis of what happened is elaborated: type of symptoms, time of onset from ingestion of the food, if it is the first time it happens and it was referred spontaneously or with medication and of what type.

Subsequently, it is decided whether it is necessary to perform skin tests (prick tests) and blood tests to determine specific IgE for cow’s milk proteins.

According to the results, the performance of a controlled oral challenge test with cow’s milk will be assessed. This test consists of eating the food in progressive amounts under the supervision of an allergy specialist. Its goal is to confirm or rule out cow’s milk protein allergy. If the test result is positive, there is an allergy, it allows to know the threshold dose with which the patient presents symptoms when eating the food, avoiding unnecessary or very restrictive diets.

How is the evolution and prognosis of cow’s milk allergy?

Cow’s milk protein allergy tends to evolve into spontaneous remission in the short to medium term.

Clinical food tolerance is favorable in most infants and young children with IgE-mediated allergies. From 4 years of age, spontaneous tolerance is less likely. It is estimated that from 6-7 years of age cow’s milk protein allergy persists in 10%.

What is the treatment for cow’s milk allergy?

After the evaluating and diagnosing cow’s milk allergy, the elimination diet is the initial treatment of choice. This diet consists of the elimination of all cow’s milk proteins and foods that contain them. Cow’s milk can be replaced by hydrolyzed, elemental, soy or rice formulas.

For persistent cases that do not reach spontaneous tolerance, there is “Oral Immunotherapy” treatment, which consists of the progressive intake of food according to protocols and always supervised by an allergy specialist. Due to the risk involved, “oral immunotherapy” should be performed in the hospitall. The purpose of this treatment is to modify the allergic response by making the patient desensitized or tolerant to cow’s milk.

Remember to request the assessment of your allergy specialist if you suspect cow’s milk allergy, from ClinicAL we hope to have provided information about this allergy so frequent in the pediatric age.

Dra. Jaritzy Negrín González
Allergy Specialist

Allergy to the sun

Allergy to the sun 1920 1280 Federico de la Roca Pinzón

In summer, or even in spring, they consult us about “sun allergy” symptoms. In general, these are patients who, after being exposed to the sun for a couple of hours, have presented itchy skin and skin lesions that they describe as “rash or rash”.

Can the sun cause “allergy”?

Ultraviolet radiation from sunlight is one of the main environmental factors affecting human health. The most frequent reactions produced by sun exposure are sunburn and tanning. If exposure is repeated, chronic skin changes occur that can trigger cancer and photoaging. But solar radiation can also alter the immune system leading to an abnormal skin reaction after sun exposure. These abnormal reactions are known as “photodermatosis” and usually include those skin lesions that patients known as sun allergy.

What is photodermatosis?

As mentioned before, photodermatosis is an abnormal skin response caused, triggered or aggravated by exposure to radiation emitted by the sun. The clinical manifestations are very varied and range from itching, to skin lesions such as hives, exanthema (redness), eczema or even scabs.

Which are the most frequent photodermatoses?

The most frequent photodermatoses secondary to the interaction between solar radiation and the immune system are polymorphic light eruption, solar urticaria and chronic actinic dermatitis. Each of these manifests itself in a different way, but in some cases, especially those with many years of evolution, the skin lesions can overlap, generating confusion when establishing the diagnosis. It is important to remember that solar radiation can also worsen atopic dermatitis.

What is the Polymorphic Light Eruption?

It is the most common photodermatosis in our setting, being the adult population the most affected. Young women, especially those between the second and third decades of life, are the ones who present the most.

Polymorphic light eruption is the skin reaction that most patients describe as “sun allergy”. This is because symptoms can occur within a few hours of receiving sunlight and usually start with itchy skin that is then accompanied by papules, vesicles, eczema, plaques, erosions and scabs. It is because of these different forms of skin lesions that it is called “polymorphic eruption”. The face, neck, upper thorax, forearms and legs may be affected.

The main cause is sun exposure, it usually appears at the end of spring and improves as the summer progresses. This improvement is due to the fact that repeated exposure to the sun facilitates a phenomenon  called “hardening”. This phenomenon is a process of photoadaptation that the skin develops as sun exposure increases progressively, creating “resistance” or solar tolerance.

What is Solar Urticaria?

As in polymorphic light eruption, it is a common photodermatosis in young adults (especially between 20 and 30 years of age) and in females. Despite its “popularity” among reactions due to the sun, solar urticaria is a rare condition. It only represents 0.4% of all cases of urticaria.

Solar urticaria is characterized by skin itching accompanied by habonous lesions (wheals/hives). Syntomas usually starts very quickly after sun exposure. At first it is only itching and erythema (redness), but as time progresses, hives appear. The condition usually resolves spontaneously within 24 hours, without scarring.

The most affected sites are those known as “photoexposed areas” which include neck, arms and forearms. As also happens with polymorphic light eruption, in solar urticaria, repeated exposure to the sun facilitates the “hardening” of the skin, which is why the face and the back of the hands may not present lesions despite being areas more commonly exposed to sunlight. When large areas of the body are affected, the skin condition may be accompanied by headache, malaise, nausea, and cardiovascular symptoms, such as tachycardia, hypotension, and even shock.

What is Chronic Actinic Dermatitis?

It is the photodermatosis with the largest worldwide distribution, being more frequent in temperate regions and in men over 50 years. They are usually patients with a history of significant sun exposure.

Lesions appear on exposed skin areas with sharply separating cut lines where clothing protection begins. They are patchy lesions that appear in the form of eczema. In severe cases, lesions may become lichenified. When the condition is very intense, it can affect the palms and soles, there are even patients who can lose the hair of the eyelashes, eyebrows and scalp, generally secondary to scratching.

It is common to worsen in the summer, developing lesions within minutes or hours after exposure to the sun which, occasionally, may recur after several days, if exposure stops and the reaction is mild. In severe forms the patient may have lesions throughout the year.

How can photodermatoses be prevented?

The best prevention is adequate photoprotection. For this we must avoid direct sun exposure, wear clothing that covers the most photoexposed areas and apply sunscreens (UVA and UVB).

Is there a specific treatment for photodermatoses?

Currently there are many treatments for the control of photodermatoses. These range from antihistamines, corticosteroids, immunosuppressants and even ultraviolet radiation. Treatment must be individualized since, as we saw earlier, the clinical manifestations are diverse and can occur at different stages of the disease.

At ClinicAL ​​we hope to have provided information on the most frequent skin reactions caused by sun exposure, which are so frequent in these months.

¿Any doubts?

Contact with us

Dr Federico de la Roca
Especialista en Alergología.

Allergy to pine pollen and pine processionary caterpilar

Allergy to pine pollen and pine processionary caterpilar 1920 1280 Jaritzy Negrín González

Allergy to pine pollen is not common. It can become relevant in areas with high concentrations, for example in the Basque Country and Galicia.

Symptoms can be nasal, ocular or bronchial. Generally, the patient is monosensitive, that is, he has no allergy to other pollens.

What is the pine processionary caterpillar?

The processionary caterpillar is an insect that lives in pine trees and has 4 stages of development: moth, egg, larva and chrysalis. It receives the name of processionary because they parade as in a procession.

In their larval phase they have microscopic hairs whose function is to defend against possible predators. In the mature phase, after leaving the pine trees, the caterpillar can releases up to more than 1 million of these hairs

What are the symptoms produced by the pine processionary caterpillar?

More frequently, it causes itching and skin lesions in exposed areas (arms, legs and face) due to the penetration of the hairs. In children, injuries to the palms of the hands are typical because they try to catch the caterpillars.

Injuries can be:

-Dermatitis with scratching lesions and eczema.

-Contact urticaria which may be associated with angioedema of the eyelids.

-Less frequently, lesions such as vesicles or pustules.

It can also produce ocular symptoms such as conjunctivitis or keratitis.

Respiratory symptoms are less frequent, which can be associated with anaphylaxis.

Why do the symptoms occur?

The mechanism involved in the production of this reaction is usually mechanical or irritative, although it is sometimes produced by an IgE-mediated mechanism.

Who can affect?

It can produce symptoms in anyone who has been exposed to pine forest areas.

It has also been described as an occupational disease in resin collectors, lumberjacks, farmers or ranchers, due to their high exposure to caterpillars.

How can symptoms be treated?

If you present the symptoms described, you should request an assessment by your allergy specialist and the case will be evaluated.

Treatment is symptomatic according to the clinical picture: oral antihistamines, topical or oral corticosteroids. And in severe cases (anaphylaxis) it will be necessary to use adrenaline.

Do you have any doubt?

Dr Jaritzy Negrín González
Especialista en Alergología.

Allergic reactions and COVID-19 vaccines

Allergic reactions and COVID-19 vaccines 1270 768 Federico de la Roca Pinzón

We are currently immersed in a COVID-19 vaccination campaign (SRAS -CoV-2) and there are many doubts about this regard.

“From ClinicAL we want to convey that vaccination, with the different vaccines approved by the European Medicines Agency (EMA) and the Spanish Medicines and Health Products Agency (AEMPS), is safe.”

Currently, 4 vaccines have been approved for use in Spain, that of the Pfizer, Moderna, AstraZeneca, and Janssen laboratories. Although there is some fear in the population due to the adverse effects reported in recent days, especially with the AstraZeneca vaccine, it is our duty as physicians to remember that the benefit of being vaccinated is greater than the risk of not being vaccinated.

Side effects, although undesirable, are present in every one of the drugs available today. No medication is exempt from producing any adverse symptoms. It is very likely that at some point someone vaccinated will experience symptoms after administration of any of the approved vaccines. But to prevent these effects from being frequent and severe, all laboratories have had to carry out clinical trials with thousands and thousands of patients.

“It is important to remember that no medication in Europe is marketed without proper approval from the EMA. Due to the great responsibility that this entails, this agency is an independent institution and its resolutions are followed by all the member countries of the European Union. Under no circumstances is the latter the ones who issue orders on the EMA.”

In the case of allergic patients, scientific societies have made several recommendations for the administration of the various vaccines against COVID-19 (SARS -CoV-2). In general, all allergic patients can be vaccinated with the 4 vaccines we currently have. The only ones that would be exempt are those with an allergy to some component of the vaccine. The main recommendations are based on the observation period following administration of the vaccine. For those patients with rhinitis, asthma, food or drugs allergies (other than vaccine components) the post-vaccination monitoring time should be 30 minutes. For patients with a history of severe allergic reactions (anaphylaxis) the time under observation should be 45 minutes.

As always, from ClinicAl we remember that our consultations are available to those patients who have doubts about their allergic disease and especially for those who need more information about the vaccination campaign against COVID -19 (SARS -CoV-2) and its likely adverse effects.

Dr. Federico de la Roca Pinzón
Allergy Specialist

Pollen allergy

Pollen allergy 1270 768 Jaritzy Negrín González

Spring is coming and with it the symptoms in our pollen-allergic patients.

Pollens are microscopic grains, invisible to the human eye that are scattered in the air.

“In our area, the most frequent pollens are Cypress, Plane-tree, Parietaria, Grass, and Olive. Pollen levels increase depending on the time of year, for this reason not all pollen-allergic patients have symptoms in the same months of the year.”

You can know the pollen calendar and weekly count levels by accessing “Aerobiological Information Point of Catalonia” through this link:

“Pollen allergy can occur with rhinoconjunctival symptoms (sneezing, nasal or ocular itching, mucus, nasal congestion…) and/or bronchial symptoms (shortness of breath, cough, whistling…) You should go to your allergy specialist to find out which pollen or pollens are causing your symptoms and indicate proper treatment.”

If you are a patient allergic to pollen we can recommend:

  • Keep the windows of the house closed as possible. Ventilate the home for a short time and preferable first thing in the morning or at night.
  • Travel by car with the windows closed.
  • Hang clothes inside the house, not outside.
  • Avoid outdoor physical activities; especially when the pollen count is high.
  • The use of glasses is preferable to contact lenses, since pollen can be trapped between them and the eye.

Dr. Jaritzy Negrín González
Allergy Specialist