Easily confused: Influenza infection and allergy

Wintertime is a cold season: You see people with coughs and runny noses everywhere. However, there is not always a flu-like infection behind the symptoms. “It often happens that a blocked nose, breathing difficulties or a cough in the winter months are mistaken for symptoms of a cold, although an allergy is the cause,” says Professor Dr Ludger Klimek from the Medical Association of German Allergists (ÄDA). The Wiesbaden ENT doctor and allergist reports that he unmasks several patients with alleged flu every week during the winter months as allergy sufferers.

Allergy or cold?

Eleven-year-old Felix had been suffering from a runny nose, cough, headache and heavy congestion for six weeks when he visited the practice of specialist Professor Ludger Klimek, accompanied by his mother. The family doctor had previously prescribed three different antibiotics, but none helped. Even expectorant, cough-suppressing medication and homoeopathic preparations gave Felix only brief relief. The boy was frustrated because absenteeism from school and his poor condition jeopardised his grades.

“Mother told me that Felix gets a long ‘cold’ every year at this time,” reports Klimek. “The regular occurrence of the same complaints at certain times of the year or in certain situations is an important indication for the allergy specialist.” Klimek carried out an allergy test on Felix and identified a severe allergy to house dust mites and cat hair as the cause of the regularly recurring complaints. “It is precisely the mite allergy that causes symptoms such as coughing and runny nose, especially in autumn at the beginning of the heating period, which can easily be mistaken for a flu-like infection,” explains Klimek.

Allergies can express themselves in different ways and have many other causes. Pollen, house dust mites, animal hair and mould can trigger an allergic cold and itchy eyes (hay fever) in sensitive people. However, if the bronchial mucosa reacts allergically, it can also lead to asthma, such as coughing, wheezing, and shortness of breath. In allergic asthma, the airways are narrowed by an allergic inflammation because the bronchial mucosa swells, thick mucus forms and the muscles in the airways cramp.

Symptoms of respiratory allergies and influenza infections are similar.

The symptoms of respiratory allergies can easily be mistaken for a common cold. Both diseases often cause a runny nose, sneezing, reddened eyes, coughing, difficulty breathing and exhaustion. “Infections with the flu are often accompanied by fever. Itching is common for allergies; for example, the nose or eyes can be itchy. Fever is rare,” says Professor Klimek. Signs of an allergy are also constant symptoms or symptoms that recur in certain situations or times.

Causal allergy therapy helps in the long-term

Those affected should consult an ear, nose, and throat doctor specialising in treating allergies if they are in doubt. A detailed questioning of the patient gives the doctor information about whether an allergy or an infection is present. Physical examination and laboratory tests provide additional clues. The specialist often finds purulent secretions and swollen lymphatic tissue in the case of flu-like infections or a non-allergic cold. Allergies can be detected with a skin test. A blood test also shows increased immunoglobulin E (IgE) antibodies typical of allergies.

Eleven-year-old Felix is ​​now receiving specific immunotherapy (SIT) with standardized mite allergens, so next year, he will probably not be absent from school for weeks because of his allergic “flu”. The cause of the allergy can be treated with SIT. The therapy accustoms the hypersensitive immune system of allergy sufferers to the allergy triggers in the long term. As a result, the symptoms reduce in the long term or do not occur at all. In addition, immunotherapy can significantly reduce the risk of developing asthma.