Allergy can manifest in many different ways. Different symptoms may appear at the same time, or at different times in a sufferer's life :

Epidemiological studies have been shown that the life of an allergic individual starts at a very young age.

If an infant is atopic, he/she has a risk of developing allergies which is linked to familial factors but also to exposure to allergens. He/she will start his allergic life with sensitisation to foods.

These food allergies, which are very common in infants, then have a tendency to decrease or even disappear within the years.

He/she may after be sensitised to inhaled allergens resulting in respiratory allergies such as asthma or rhinitis. Dust mites are responsible for 80% of allergic asthma in children.

Thereafter, sensitisation to other allergies can occur in the individual. This is referred to as multiple sensitisations.

Respiratory diseases

Allergic rhinitis

Allergic rhinitis is a seasonal or perennial problem which manifests principally as the combination of nasal obstruction, a runny nose (rhinorrhea), repeated sneezing and itching of the nose or palate (pruritus of the nose or palate).

These symptoms reflect the inflammation triggered by interaction between one or more allergens and specific IgE antibodies, an interaction which provokes a series of complex cell-mediated processes, the allergic reaction.

                                                                    Learn more about rhinitis 

Allergic asthma

Allergic asthma is characterised by intense respiratory difficulty, wheezing and cough (most often at night).

These symptoms result from the inflammation of the bronchial tubes, which leads to a contraction of the muscles controlling their opening: the passage of air is disturbed, exhalation can no longer be performed normally and breathing results in wheezing. These symptoms are combined with a hypersecretion of mucus (causing the cough) and bronchial oedema. Asthma attacks can range from a simple shortness of breath to serious respiratory failure requiring hospitalisation. In children, asthma may inhibit chest development and have a negative impact on both family life and life at school.

                                                                    Learn more about asthma

Skin diseases

Eczema

• Atopic eczema Atopic eczema (also called atopic dermatitis) occurs very early in the life of the infant. It is characterised by epidermal induration (the skin is hard and unyielding), redness and itching, sometimes combined with edema. These patches typically appear on the face, scalp and at skin folds of joints (e.g. in the groin, the back of the knee or the armpits). Without treatment, atopic dermatitis leads to drying out of the skin. Certain proteins in cow's milk have often been suggested as the cause of this form of eczema ("allergy to proteins in cow's milk").
• Contact eczema Contact eczema tends to affect adults and is associated with a red patchy rash, tiny blisters (small pimples on the surface of the skin filled with fluid) and severe itching (doctors call this pruritus). The lesions are concentrated at the points of contact of the allergen with the skin and appear two to three days after contact.

 
Allergic urticaria Allergic urticaria often develops soon after a certain drug or food has been ingested. It shows up as a group of small red papules (small spots on the skin) or raised patches on the skin, together with severe itching, and can extend over the entire body.

Angioedema Angioedema is a special form of urticaria associated with edema. The onset of this condition is very sudden. It has a deep impact, extending from the skin to subcutaneous tissue, and sometimes even to the mucous membranes. Often confined to the face, a more serious form of the edema may affect the upper aerodigestive tract (the throat and larynx), in which case suffocation may ensue within a matter of minutes, with a drop in blood pressure and loss of consciousness. This phenomenon is called anaphylactic shock and requires emergency treatment (in particular, an epinephrine injection). Angioedema is linked to a food allergy, drug allergy or sensitisation to hymenoptera venom (bee, wasp or hornet).

Eye diseases

Allergic conjunctivitis is a condition that manifests itself through tearing, red eyes and smarting, increased sensitivity to light, and red and swollen eyelids.

It is often linked to allergic rhinitis this is referred to as allergic rhinoconjunctivitis.
 

Anaphylactic shock

Anaphylactic shock is an exacerbated allergic reaction, resulting in most cases in serious consequences and can be life-threatening.

It is a manifestation of immediate hypersensitivity due to the release of vasoactive mediators in a previously sensitised individual.

Anaphylactic shock may lead to a drop in blood pressure and an accelerated heart rate (tachycardia). Respiratory disorders and gastrointestinal disorders (nausea, vomiting, disorders of deglutition (swallowing), diarrhea) are associated.

Death may occur via circulatory collapse which stops the heart, or by a major spasm of the bronchial tubes, resulting in a state of asphyxiation, or by pulmonary edema.

The symptoms most often observed (isolated or in combination) are:

• Skin signs (skin rash, pruritus (itching) (of the lips, mouth, eyes), edema of the face)
• Respiratory signs (dyspnea, edema of the glottis, bronchospasm, sneezing, cough)
• Gastrointestinal signs (vomiting, nausea, abdominal pain),
• Dizziness, palpitations, chills and loss of consciousness that can lead to coma.

There are signs of cardiovascular collapse and hypotension.

 
Why is there such a large variety of symptoms?

To top