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Federico de la Roca Pinzón

Bees and Wasps

Bees and Wasps 2560 1627 Federico de la Roca Pinzón

Bees and wasps belong to the insect order Hymenoptera. These get their name from their characteristic membranous wings. In the case of bees and wasps, there are 2 pairs of wings, the later ones being a little smaller than the previous ones. From an allergological point of view, their importance lies in the fact that they are responsible for the vast majority of allergic reactions due to insect bites.

Are bees and wasps dangerous insects?

No, both bees and the different species of wasps that inhabit the Iberian Peninsula are not considered dangerous insects. Although they can adopt an aggressive attitude, this usually only happens when they feel threatened, especially if we get too close to their nests.

Why do bees and wasps sting?

The bite of these insects is a defense measure rather than an attack. In many cases it can be a deterrent sting to prevent us from approaching the nest. If this measure does not work, the attitude can be more aggressive, thus leading to multiple bites by more than one insect at a time. This is what happens with wasps, which can sting more than once.

In the case of bees, they can only sting once since after the sting they die. This is because when the stinger is left at the site of the sting, it detaches from the insect, tearing its abdomen. After the sting, the bee dies by evisceration.

Are bee and wasp stings common?

Sí, al ser insectos que conviven en nuestro entorno las picaduras de abejas y avispas son frecuentes. Se estima que al menos el 56 al 94% de la población adulta ha sido picado alguna vez a lo largo de su vida por alguno de estos insectos

What types of reactions does the bite of these insects produce?

Reactions from bee and wasp stings can be divided according to the type of reaction between allergic and non-allergic, and according to the intensity of the reaction in local or systemic.

Most of the reactions that occur after the sting of a bee or wasp is a non-allergic reaction, which in most cases is a local reaction. These reactions are due to the components of the venom itself. An inflammatory reaction is observed at the sting site, characterized by edema (swelling), redness, and pain. The inflammation does not usually exceed 10 cm in diameter and usually subsides between 24 and 48 hours after the sting.

In the case of allergic reactions, these are rare, and only occur in people who have previously developed an immune response to the poison. These reactions are not due exclusively to the compounds of the venom but to the immune response that they produce in the person who suffers the sting.

Allergic reactions can be local or systemic depending on the intensity of the immune response to the poison. Symptoms of allergic local reactions are similar to non-allergic ones. If the edema and redness (inflammatory reaction) extend over 10 cm in diameter, covers 2 joints and persists for more than 24-48 hours, it is considered an extensive local reaction. In general, local reactions, even in allergic patients, are not severe.

Systemic reactions are rare, but they are the most severe. After the sting, in addition to the local inflammatory reaction, patients allergic to the venom may experience skin symptoms such as itching and “wheals” all over the body (acute urticaria), abdominal pain with nausea and vomiting, respiratory distress, low blood pressure (hypotension) and loss of consciousness (syncope). The presence of hypotension or syncope after a bee or wasp sting indicates that the patient is suffering from anaphylactic shock and requires immediate emergency attention since her life is in danger.

How does an allergic reaction differ from one that is not?

In general, the difference is established by the intensity of the symptoms. If it is limited to a local inflammatory reaction at the site of the sting that does not exceed 10 cm in diameter, it is very likely that we are facing a non-allergic local reaction. If the inflammation extends more than 10 cm in diameter or if it includes any other symptoms such as generalized itching, abdominal discomfort, respiratory distress or loss of consciousness, the probability that the patient is allergic is very high.

How do I know if I’ve been bitten by a bee or a wasp?

It is common for patients to have been stung by an insect, but cannot identify it, either because they did not see it at the time of the sting or because they cannot differentiate a bee from a wasp (or any other insect). If at the site of the sting the stinger is observed it is very likely that the insect responsible is a bee. Bees die after the sting so a bee can only sting once. If several bites are suffered at once and none of them shows the stinger, it is very likely that the sting is due to wasps.

How do I know if I am allergic to bee venom or wasp venom?

Whenever an allergic reaction to bee or wasp venom is suspected, an allergy specialist should be consulted. The symptoms that were had after the sting provide a lot of information about the type of reaction presented. If the symptoms are compatible with an allergic reaction, specific blood tests are carried out, as well as skin tests with the venoms of bees and wasps. These last tests are not exempt from risk, so they should only be carried out by experienced personnel and in facilities suitable for them. They are not tests that are performed routinely in outpatient clinic. As a whole, the information on the reaction after the sting, the values ​​of the blood tests and the results of the skin tests allow to diagnose those patients allergic to the venom of bees or wasps of those who are not.

If I am allergic to wasp venom, am I also allergic to bee venom?

No, generally not. Although some of the venom components of wasp venom are similar to that of bees, it is rare for a person allergic to wasp venom to be allergic to bee venom as well. It is more common to be allergic to two different species of wasps.

How are local sting reactions treated?

The first thing is to remove the stinger, if any. In bees, the stinger is attached to the sac that contains the venom, so even if the insect is dead, the sac can continue to release venom and introduce it into the skin through the stinger. Next, it is advisable to wash the bite sting and thus avoid the risk of future infections. Depending on the intensity of the symptoms, a topical corticosteroid cream and local cold (ice) can be applied. Oral antihistamines and corticosteroids are recommended if the discomfort is very intense or in case of extensive reactions. Massaging the sting area should be avoided, as well as the application of local heat.

How are systemic sting reactions treated?

In addition to general measures, such as removing the stinger (if any) and washing the sting site, the most effective measure to control and stop the progress of a severe allergic reaction to bee and wasp venom is the use of adrenaline. It is for this reason that every allergic patient should have an “emergency kit”. These kits must contain at least 2 adrenaline auto-injectors, antihistamines and oral corticosteroids.

In case of doubt, if a patient allergic to bee or wasp venom is stung, they should use the adrenaline autoinjector. The side effects produced by adrenaline are minimal, while the benefits are maximum. Adrenaline auto-injectors can save lives.

How can I prevent bee and wasp stings?

The best measure to avoid bee and wasp stings is to stay away from their nests. As we have mentioned before, these insects bite in most cases because they feel threatened and the sting is nothing more than a defence mechanism.

Most of the stings occur in the months of April to October. These are the months in which these insects increase their activity. Both bees and wasps are attracted to bright colours, floral fragrances, water surfaces, and fresh foods. Therefore, if we go out into the countryside in these months, we should avoid wearing bright colours, using colognes or fruity perfumes, not leaving sugary drinks such as juices or soft drinks exposed, avoiding riverbanks and dodge the fields with abundant flowers. If despite all these recommendations we are in close contact with a bee or wasp, we should not make sudden or rapid movements, nor should we try to kill the insect (especially if it is resting on any part of our body). The insect will most likely walk away on its own without causing any harm.

At ClinicAL ​​we hope to have provided information on the reactions caused by bee and wasp stings that are quite frequent in these months

Any doubt?

Contact with us


Dr Federico de la Roca
Allergy Specialist
ClinicAL

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.
ClinicAL

Differences between alergic rhintis and cold

Differences between alergic rhintis and cold 1920 1280 Federico de la Roca Pinzón

When we have congestion, runny nose and sneezing, most of us think we are facing a cold. But what about those people who have allergic rhinitis? In them nasal congestion and sneezing are very frequent symptoms. How can a person with allergic rhinitis differentiate the symptoms of a cold from those of rhinitis? In this post we try to answer this and other questions related to allergic rhinitis and cold.

What is rhinitis?

If we look for the definition of rhinitis we will find that it is inflammation of the nasal mucosa, which is usually accompanied by nasal discharge, congestion and sneezing. As you can see, any of these symptoms can occur in the cold as in allergic rhinitis. Therefore, what at first glance seems to be a very simple distinction in non-allergic people, the differentiation is more complex in those who suffer from allergic rhinitis and catch a cold (something very common in the autumn and winter months).

What is cold?

If we also review the different types of rhinitis we find that the common cold is also a type of rhinitis, an acute infectious rhinitis. Therefore, neither the definition of rhinitis nor its classification help us to solve a very frequent question in allergology consultations: I don’t know if what I have is rhinitis or a cold?

How to differentiate cold symptoms from those of allergic rhinitis?

Despite the fact that, as we have seen, the symptoms are very similar, there are small differences that can be helpful in distinguishing a cold from allergic rhinitis:

COMMON COLD

  • Mucous/thick nasal discharge.
  • Yellow or green discharge.
  • It can associate fever and malaise.
  • Sometimes it can be accompanied by a headache.
  • Sore throat and cough with expectoration may also appear.
  • It usually requires 5 to 10 days for recovery.

ALLERGIC RHINITIS

  • Runny nose.
  • White or clear discharge.
  • It is NOT associated with fever or malaise.
  • Sometimes it can be accompanied by itchy nose and eyes.
  • Sometimes there is itchy throat or a feeling of mucus in the throat
  • Symptoms may subside in less than 24 hours.

And if you can’t tell a cold from allergic rhinitis, what can I do?

If, despite the differences listed above, it is not  possible to  distinguish whether it is an allergic rhinitis or a cold, can I take my allergy medication, even if it is a cold? The answer is yes. Anti-allergic medication, nasal corticosteroids and oral antihistamines, can be taken in case of a cold. In fact, many flu medicines contain antihistamines, although usually in the middle of the usual dose. In addition, if we remember, the cold is a type of rhinitis, so inflammation of the nasal mucosa, even if it is of infectious origin, can be treated with nasal corticosteroids.

The problem could occur in the continued use of oral antihistamines in the case of a cold instead of allergic rhinitis. A good time to stop taking antihistamines is the presence of thick, yellow or green nasal secretions. These secretions respond better to nasal washes or mucolytic than to antihistamines.

What precautions can I take not to catch a cold?

There is no specific precaution to avoid colds. But as it is an infection of viral origin, it is recommended:

  • Frequent hand washing with soap and water for at least 20 seconds. If soap and water are not available, hydroalcoholic gel can be used if it contains at least 60% alcohol.
  • Avoid touching your face, eyes, nose or mouth with dirty hands.
  • Frequently clean and disinfect frequently touched surfaces (mobile devices, keyboards, doorknobs, etc.).
  • Avoid close contact with anyone who has symptoms suggestive of a cold.
  • If you have a cold or think you have a cold, cover your mouth when you sneeze or cough. Use tissues and throw them away immediately after use. Whenever you have contact with secretions you should wash your hands.
  • Currently the use of masks is increasingly common. Surgical masks can prevent transmission from a cold person. If you have a cold you can use this type of mask and you will protect those around you.

If I am allergic and catching a cold, what precautions should I take?

Cold symptoms in allergic people can be more intense and if not controlled can be complicated by sinusitis or trigger bronchial symptoms such as shortness of breath, choking sensation or wheezing. The recommendations to avoid these complications are:

  • If nasal congestion is important, intense nasal washes can be performed morning and night.
  • Make use of nasal corticosteroids according to the usual guideline prescribed by your allergology specialist.
  • Avoid taking oral antihistamines.
  • If you are asthmatic, you should monitor for any exacerbation of asthma. If you have bronchial symptoms you should return to your usual inhaler and perform it according to the guideline prescribed by your allergology specialist. If you are already being treated with an inhaler you can double the dose until it is evaluated by a physician.
  • If the nasal symptoms last for more than 10 days, associate high fever or difficulty breathing despite the use of a bronchial inhaler you should go to a medical evaluation.

At ClinicAL we hope to have responded to a very common situation in these cold months where colds are very frequent and their complications can be very important in patients with allergic rhinitis.

¿Tienes alguna duda?

Contacta con nosotros y te ayudaremos a resolverla.


Dr Federico de la Roca Pinzón
Especialista en Alergología.
ClinicAL

Nut allergy

Nut allergy 1920 1275 Federico de la Roca Pinzón

Nuts are, with fruits, the first cause of food allergy in adults and one of the first causes in children.

What are Nuts?

Nuts belong to different and unrelated botanical families. Most are fruits (almond, hazelnut, walnut, pistachio, chestnut and macadamia nut), some are seeds (sunflower seeds, pumpkin seeds and pine nut) and in recent years, Brazil nut and cashew, both considered fruits, have been included in our diet.

Nuts have a high nutritional power and are very important in the diet. They are consumed directly in dried form or as part of bakery and pastry products, in ice cream, in sauces or oils.

What are the nuts that produce the most allergy?

Unlike what is popularly thought, the repeated consumption of a food increases the risk of developing allergy to that food, it is for this reason that the nuts that produce the most allergy are the most consumed. In our midst, hazelnut, walnut and almond are the nuts that most often cause allergic reactions.

Why are they a major cause of food allergy?

Nuts are important in the field of allergy for several reasons, including:

a) they are one of the main causes of allergic reactions to food,

b) They frequently produce severe reactions, which can be life-threatening

c) It is one of the most frequent causes of anaphylaxis

d) They are hidden allergens and small amounts can produce serious reactions and

e) They are a frequent cause of cross-reactivity with other nuts or with other plant foods.

Who is responsible for nut allergy?

Foods are made up of a diversity of nutrients, such as carbohydrates, vitamins and proteins. It is the latter, proteins, that have the ability to develop reactions in allergic people. In the case of nuts there are 2 main groups of proteins, storage proteins and lipid transfer proteins (LTP). LTP’s are the proteins that are most often related to severe reactions in the Mediterranean area.

What about peanuts?

Peanuts, although consumed as a nut, belongs to the legume family. Legumes are plants characterized by the fact that their fruits are enclosed in pods.

Peanut allergy is a real public health problem in Anglo-Saxon countries due to its high consumption. It is estimated that in these countries 50% of peanut allergy reactions are severe, associating respiratory distress, arterial hypotension, and in some cases death. In our environment the consumption of peanuts is increasing day by day, so in the coming years it is expected that cases of peanut allergy will also increase.

Unlike other foods, in which the increase in temperature during cooking degrades the proteins responsible for allergic reactions, in the case of peanuts it has been proven that heat increases the ability to develop allergic reactions, that is, once roasted, the peanut becomes more “allergenic” and increases its resistance to gastric digestion processes.

What symptoms does nut allergy produce?

Symptoms can vary from individual to individual, as well as their severity and intensity. Some allergy patientes may have itching in the oral cavity, tongue, and lips (oral allergy syndrome). In addition to itching, the presence of lip edema, lip and cheek erythema is common. The itching can spread to the ear canals and throat. In general, these symptoms appear when the oral mucosa comes into contact with the nut.

Sometimes oral symptoms may be followed by skin manifestations with the presence of redness, itching and hives (urticaria). Digestive tract involvement can present as abdominal pain, vomiting and diarrhea. The airway could also be compromised producing cough, tightness of the chest, choking and wheezing. Finally, when the reaction is severe, it can alter blood pressure, producing a rapid drop in blood pressure (anaphylactic shock) that is usually accompanied by generalized paleness and cold sweating. Some allergy patients may also have rhinoconjunctival symptoms, such as sneezing, mucus, nasal congestion, itchy eyes, and watery eyes.

Symptoms can develop minutes after ingesting the nut, or take a few hours. The symptoms that appear immediately, before 15 minutes of ingestion of the food, are usually of mild intensity and disappear within a few minutes of its onset (oral allergy syndrome). The progress of oral symptoms with involvement of the skin, digestive and respiratory system are signs of poor prognosis, since in the case of serious reactions that affect more than one system (anaphylaxis) their resolution requires emergency medical attention. In general, most reactions due to allergy to nuts occur in the first 60 minutes after ingestion of the food, although there are cases in which the reactions have occurred 3-4 hours later.

Who can have more severe reactions?

Patients with multiple food allergies are considered to have a higher risk of more severe reactions than those with only a certain food allergy. In the Anglo-Saxon population, peanut allergy is considered a risk factor for developing serious or fatal reactions, being one of the most frequent causes of anaphylaxis.

Severe reactions to nuts are more frequent in asthmatics, with previous episodes of severe reactions and in those who have had reactions with minimal amounts of nuts (traces).

As with other food allergies, the severity of nut allergy reactions can be influenced by cofactors such as sleep deprivation, physical exercise, menstruation, or the concomitant use of alcohol or non-steroidal anti-inflammatory drugs ( NSAIDs). All of these cofactors increase the risk of serious reactions.

Are there differences between children and adults?

Allergy to a single nut is more common in children of younger age, while adult patients have allergy to multiple nuts. It is believed that these differences are due to the fact that, during growth and development, from childhood to adult life, there is a progressive exposure to these foods, this repeated exposure being responsible for the development of new allergies.

How is nut allergy diagnosed?

The medical history plays a fundamental role in the diagnosis of food allergy. A detailed clinical history can exclude multiple causes of allergic reactions, thus allowing all efforts to be concentrated on those most suspicious agents.

Skin tests (prick test) with suspicious foods is the first step in the allergy study, but it must be remembered that a positive result only indicates “sensitization” and not necessarily allergy. This is followed by the detection of specific antibodies in the blood. Currently, it is possible to detect specific antibodies for the main proteins responsible for allergic reactions (molecular diagnosis).

In some cases it is necessary to do skin tests with fresh food (prick by prick). This technique is used in situations when skin tests and antibody detection are not available for the suspect food or when there are divergences between the tests results.

Finally, an oral challenge test may be performed to confirm or rule out allergy to the suspected nut. This test carries risks, so it is performed only in some cases, in a controlled environment, in a hospital facility and always under the supervision of an allergy specialist..

Is there any treatment?

As with other types of food allergy, the only treatment currently available is strict avoidance of the food involved. Therefore, the first recommendation involves eliminating implicated nut rom the diet.

Allergic reactions to nuts are treated like any allergic reaction. The use of adrenaline can save lives in cases of severe reactions. If the patient has suffered a severe reaction to nuts or there is a risk of accidental ingestion, it is advisable to have self-injectable adrenaline devices.

In recent years, “vaccines” have been tested to treat peanut and hazelnut allergy. These “vaccines” have managed to significantly increase the amount of nuts that allergy patients can tolerate, thus reducing the risk of severe allergic reactions caused by ingestion. At the moment it is a line of treatment that is under investigation and that is not yet commercialized.

Programs are also being developed using monoclonal anti-IgE antibodies. These antibodies can modify the immune system and create tolerance to foods that were previously allergic to. At the moment this treatment is limited to children and adolescents with severe food reactions, which are life-threatening.

Can nut allergy be prevented?

At the moment there is no measure to prevent the development of food allergies, but there are measures to avoid the accidental consumption of certain potentially allergenic foods. For some years now, all foods containing peanuts and nuts that are marketed in the European area must specify this on the label. This rule applies both to packaged foods, as well as to those presented unpackaged, as well as to foods prepared for immediate consumption (restaurant menu).

What about nut-free diets?

In the past, it was proposed, as a measure to avoid future allergy in children, the elimination by the mother of foods considered to be more allergenic (milk, egg, nuts) during the third trimester of gestation and during breastfeeding, as well as the delay in the introduction of high-risk foods into the child’s diet. The current international consensus does not recommend these measures, since it has not shown any effect on the prevention of allergic diseases, while it can lead to a nutritional deficit for mother and child.

One last recommendation?

Patients allergic to peanuts must take special care in reading the labels of manufactured products, since it is one of the legumes (along with soy) that are most commonly found as part of additives from other foods (hidden allergens).

We must take into account the widespread use of nuts in sauces, ice cream, pastries or oils, which can be sources of hidden allergens causing accidental reactions.

Minimal amounts (traces) can be tolerated by most people allergic to nuts, but there is a small group of allergy patientes who may have allergic reactions with these amounts; so the recommendations about the consumption or avoidance of traces must be individualized for each case.



Dr Federico de la Roca Pinzón

Allergy Specialist
ClinicAL

Autumn allergies: molds

Autumn allergies: molds 1920 1280 Federico de la Roca Pinzón

Molds are microorganisms invisible to the human eye, but their accumulation in the form of colonies makes them visible as moisture stains on walls or in the moldy appearance in colonized food.

Molds alone does not induce allergy symptoms, they require spores to reach the mucous membranes of allergic patients. Spores are the reproductive particles of molds, but due to their small size they can travel through the atmosphere until they are deposited in the airway. It is for this reason that patients with mold allergy worsen storm days since it is the wind currents that facilitate the movement of spores in the atmosphere.

There are several factors that condition the growth of molds such as humidity, temperature, nutrients, light, oxygenation, geography, etc. Humidity, which is the amount of water present in the air, is the main factor for the development of molds. It is estimated that from 70% humidity an environment conducive to the growth of molds is created. Due to the close relationship between molds and moisture, sometimes both terms are mixed generating confusion.

Therefore, humidity or what is the same, the water of the environment does not produce allergy symptoms, it is the molds and specifically the spores of these that are responsible for the allergic disease.

Temperature is also important for mold growth. In general, they prefer warm temperatures, which is why molds develop best in spring though autumn. Rain influences spore concentrations, this is because the vibration generated by the impact of the drops on colonized surfaces releases spores. Warm temperatures and rain are two elements very present in late summer and early autumn. In these months is when the largest number of spores in the atmosphere is recorded.

Molds get their nutrients from any organic compound, mainly those of plant origin. The main sources of spores that are released into the atmosphere come from decaying leaves, grass fields, hay  and grain storage.

What molds cause allergic diseases?

Among the molds that are most frequently associated with allergic diseases are Alternaria,  Cladosporium,  Penicilium,  Aspergillus  and  Candida species.

Alternaria is a very ubiquitous and universally distributed mold. It is also one of the molds with the greatest capacity to induce allergy symptoms. Patients allergic to  Alternaria  are at increased risk of asthma, severe asthma, and even fatal asthma. It has been observed that exposure to this mold is closely related to an increase in visits to emergency services for asthma, especially in the pediatric population.  Alternaria spores can be found practically all year round, with maximum exposures in hot months. In Catalonia the highest concentration of spores is detected in the months of April to November.

Aspergillus is the second most important mold to produce allergy symptoms after  Alternaria.  It is also very distributed and its presence is almost constant in the atmosphere. It has great  resistance to extreme temperatures, being able to develop at temperatures between 12 to 52ºC (being the optimal 40ºC). It even resists pasteurization.

Cladosporium is not as aggressive as  Alternaria  or  Aspergillus. There is not always direct relationship between spore counts and the presence of symptoms. The concentration of spores in indoor environments is a reflection of their high presence outside. Together with  Alternaria  they are the most responsible for allergy symptoms at home. It is the dominant species in dry inland Spain, although to a lesser extent than in the Mediterranean area.

Penicilium is widely distributed and its function is to contribute to the decomposition of organic matter. It predominates in temperate climates, forests, meadows and on the surface of crops. Seasonal variations do not seem to influence spore count, but spore peaks usually occur in spring and autumn months, especially in urban areas. Its growth temperature is 23ºC.

Due to the abundant amount of nutrients, environmental factors, ideal temperatures and ease of condensation, molds usually predominate in outdoor environments. Although mold spores can be found inside the house most of the spores come from the outside.

Molds inside home

In enclosed spaces the factors that contribute the most to growth of molds are humidity, lack of ventilation and darkness. Humidity above 65% facilitates the growth of molds inside homes. In winter, warm air condenses on cooler surfaces, producing moist areas. On the contrary, in summer, poorly ventilated basements without direct sunlight are relatively cool compared to the outside air thus facilitating condensation.

The condensation of water inside the houses facilitates the growth of molds, which is why it is very common to find them in areas where the wall-ceiling and the floor meet, in the corners of the rooms, areas near the windows where cold air circulates, in airtight windows with rubber bands and behind the furniture. Other sites where molds can grow inside homes are wet textile materials, wood, stored food, and drainage pipes.

The spores are usually found as part of the household dust present in carpets, bedding, furniture or wallpaper. In low humidity conditions the spores do not have the ability to induce allergy symptoms, this is because the spore load is very low in the air. If humidity increases the number of spores, it also increases the presence of spores in the environment, thus generating symptoms in those allergic patients.

The most frequent places where we can find mold spores in indoor environments are second homes (closed for much of the year), basements, storage rooms with humidity, poorly ventilated bathrooms or in houses with wallpaper on their walls.

While outside the presence of spores and therefore the involvement of allergic patients is greater from spring to autumn, spores inside homes can cause symptoms throughout the year. It is considered that the amount of spores inside homes is directly related to the severity of symptoms regardless of the season of the year. Studies have also shown that the simple observation of damp spots or musty smell is related to symptoms of rhinitis and asthma.

Although molds are microscopic and can only be observed when they form colonies, it is possible to identify the species according to certain characteristics they present on the surface they colonize. Alternaria  can be identified as black spots on diseased or dead plants. Penicilium  is visible as bluish-green colonies on stale bread or decaying citrus fruits.

How to avoid molds?

It is impossible to completely eliminate spores from home, but there are simple measures that can help lower their levels such as ventilating rooms, reduce humidity and increase sun exposure. It is preferable to use outside air to ventilate homes. The outside air equalizes the temperature between the house and the external environment avoiding the formation of condensations. The use of air conditioning reduces humidity substantially, as well as dehumidifiers, but these must be cleaned frequently to prevent the growth of molds inside. Sun exposure also reduces the formation of colonies as it dries out surfaces making it difficult for molds to survive. In very humid houses it is recommended to use air extractors when cooking, avoid the placement of carpets  and ventilate the bathrooms properly.

Other less economical measures, but also useful, are the installation of windows with thermo-paneled glass that prevent condensation.  Using insulating building materials that prevent condensation on cold surfaces (windows, exterior walls, water pipes, ceilings or floors) is usually an effective measure.

If, despite all the preventive measures, moisture stains are detected, they have to be cleaned and the source of moisture removed. For this purpose you can use water and detergents followed by thorough drying. Bleach removes molds effectively. Alcohol can also be used to eliminate colonies.

Which patients are allergic to molds?

It is estimated that up to 10% of the general population has positive tests for molds and of these, about half will develop respiratory allergy.   The pediatric population and young adults appear to be the most frequently exhibited these positive tests. Some studies have shown that children who live in damp homes have an increased risk of developing respiratory allergies, especially asthma. In allergic patients to molds with asthma  this is usually more severe compared to those with allergy to other allergens (pollens, mites, etc.).

It has also been observed that climate change influences patients with mold allergy. There are studies that have shown a strong association between emergency room visits for asthma attacks due to the increase in mold spores triggered by thunderstorms. Other publications correlate the high concentrations of  Alternaria  and  Cladosporium spores found on stormy days with the rate of admission to the emergency room for asthma. The mechanism by which storms increase exposure to spores is the strength of wind, electric discharges and rain, all contributing to the fragmentation of spores thus facilitating the release of their allergens and their atmospheric transport.


Dr. Federico de la Roca Pinzón
Allergy Specialist
ClinicAL

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
ClinicAL